LCOV - differential code coverage report
Current view: top level - src/backend/postmaster - autovacuum.c (source / functions) Coverage Total Hit UNC LBC UIC UBC GBC GIC GNC CBC EUB ECB DUB DCB
Current: Differential Code Coverage HEAD vs 15 Lines: 79.7 % 964 768 44 34 129 22 43 488 81 156 124 503 6 43
Current Date: 2023-04-08 17:13:01 Functions: 97.1 % 35 34 1 30 4 1 33 1
Baseline: 15 Line coverage date bins:
Baseline Date: 2023-04-08 15:09:40 [..60] days: 85.9 % 78 67 11 1 66 3
Legend: Lines: hit not hit (60,120] days: 100.0 % 3 3 3
(120,180] days: 100.0 % 5 5 5
(180,240] days: 100.0 % 8 8 1 7 1
(240..) days: 78.7 % 870 685 34 129 22 42 487 156 124 499
Function coverage date bins:
[..60] days: 75.0 % 4 3 3 1
(180,240] days: 50.0 % 2 1 1 1
(240..) days: 51.7 % 58 30 1 30 1 26

 Age         Owner                  TLA  Line data    Source code
                                  1                 : /*-------------------------------------------------------------------------
                                  2                 :  *
                                  3                 :  * autovacuum.c
                                  4                 :  *
                                  5                 :  * PostgreSQL Integrated Autovacuum Daemon
                                  6                 :  *
                                  7                 :  * The autovacuum system is structured in two different kinds of processes: the
                                  8                 :  * autovacuum launcher and the autovacuum worker.  The launcher is an
                                  9                 :  * always-running process, started by the postmaster when the autovacuum GUC
                                 10                 :  * parameter is set.  The launcher schedules autovacuum workers to be started
                                 11                 :  * when appropriate.  The workers are the processes which execute the actual
                                 12                 :  * vacuuming; they connect to a database as determined in the launcher, and
                                 13                 :  * once connected they examine the catalogs to select the tables to vacuum.
                                 14                 :  *
                                 15                 :  * The autovacuum launcher cannot start the worker processes by itself,
                                 16                 :  * because doing so would cause robustness issues (namely, failure to shut
                                 17                 :  * them down on exceptional conditions, and also, since the launcher is
                                 18                 :  * connected to shared memory and is thus subject to corruption there, it is
                                 19                 :  * not as robust as the postmaster).  So it leaves that task to the postmaster.
                                 20                 :  *
                                 21                 :  * There is an autovacuum shared memory area, where the launcher stores
                                 22                 :  * information about the database it wants vacuumed.  When it wants a new
                                 23                 :  * worker to start, it sets a flag in shared memory and sends a signal to the
                                 24                 :  * postmaster.  Then postmaster knows nothing more than it must start a worker;
                                 25                 :  * so it forks a new child, which turns into a worker.  This new process
                                 26                 :  * connects to shared memory, and there it can inspect the information that the
                                 27                 :  * launcher has set up.
                                 28                 :  *
                                 29                 :  * If the fork() call fails in the postmaster, it sets a flag in the shared
                                 30                 :  * memory area, and sends a signal to the launcher.  The launcher, upon
                                 31                 :  * noticing the flag, can try starting the worker again by resending the
                                 32                 :  * signal.  Note that the failure can only be transient (fork failure due to
                                 33                 :  * high load, memory pressure, too many processes, etc); more permanent
                                 34                 :  * problems, like failure to connect to a database, are detected later in the
                                 35                 :  * worker and dealt with just by having the worker exit normally.  The launcher
                                 36                 :  * will launch a new worker again later, per schedule.
                                 37                 :  *
                                 38                 :  * When the worker is done vacuuming it sends SIGUSR2 to the launcher.  The
                                 39                 :  * launcher then wakes up and is able to launch another worker, if the schedule
                                 40                 :  * is so tight that a new worker is needed immediately.  At this time the
                                 41                 :  * launcher can also balance the settings for the various remaining workers'
                                 42                 :  * cost-based vacuum delay feature.
                                 43                 :  *
                                 44                 :  * Note that there can be more than one worker in a database concurrently.
                                 45                 :  * They will store the table they are currently vacuuming in shared memory, so
                                 46                 :  * that other workers avoid being blocked waiting for the vacuum lock for that
                                 47                 :  * table.  They will also fetch the last time the table was vacuumed from
                                 48                 :  * pgstats just before vacuuming each table, to avoid vacuuming a table that
                                 49                 :  * was just finished being vacuumed by another worker and thus is no longer
                                 50                 :  * noted in shared memory.  However, there is a small window (due to not yet
                                 51                 :  * holding the relation lock) during which a worker may choose a table that was
                                 52                 :  * already vacuumed; this is a bug in the current design.
                                 53                 :  *
                                 54                 :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
                                 55                 :  * Portions Copyright (c) 1994, Regents of the University of California
                                 56                 :  *
                                 57                 :  *
                                 58                 :  * IDENTIFICATION
                                 59                 :  *    src/backend/postmaster/autovacuum.c
                                 60                 :  *
                                 61                 :  *-------------------------------------------------------------------------
                                 62                 :  */
                                 63                 : #include "postgres.h"
                                 64                 : 
                                 65                 : #include <signal.h>
                                 66                 : #include <sys/time.h>
                                 67                 : #include <unistd.h>
                                 68                 : 
                                 69                 : #include "access/heapam.h"
                                 70                 : #include "access/htup_details.h"
                                 71                 : #include "access/multixact.h"
                                 72                 : #include "access/reloptions.h"
                                 73                 : #include "access/tableam.h"
                                 74                 : #include "access/transam.h"
                                 75                 : #include "access/xact.h"
                                 76                 : #include "catalog/dependency.h"
                                 77                 : #include "catalog/namespace.h"
                                 78                 : #include "catalog/pg_database.h"
                                 79                 : #include "commands/dbcommands.h"
                                 80                 : #include "commands/vacuum.h"
                                 81                 : #include "lib/ilist.h"
                                 82                 : #include "libpq/pqsignal.h"
                                 83                 : #include "miscadmin.h"
                                 84                 : #include "nodes/makefuncs.h"
                                 85                 : #include "pgstat.h"
                                 86                 : #include "postmaster/autovacuum.h"
                                 87                 : #include "postmaster/fork_process.h"
                                 88                 : #include "postmaster/interrupt.h"
                                 89                 : #include "postmaster/postmaster.h"
                                 90                 : #include "storage/bufmgr.h"
                                 91                 : #include "storage/ipc.h"
                                 92                 : #include "storage/latch.h"
                                 93                 : #include "storage/lmgr.h"
                                 94                 : #include "storage/pmsignal.h"
                                 95                 : #include "storage/proc.h"
                                 96                 : #include "storage/procsignal.h"
                                 97                 : #include "storage/sinvaladt.h"
                                 98                 : #include "storage/smgr.h"
                                 99                 : #include "tcop/tcopprot.h"
                                100                 : #include "utils/fmgroids.h"
                                101                 : #include "utils/fmgrprotos.h"
                                102                 : #include "utils/guc_hooks.h"
                                103                 : #include "utils/lsyscache.h"
                                104                 : #include "utils/memutils.h"
                                105                 : #include "utils/ps_status.h"
                                106                 : #include "utils/rel.h"
                                107                 : #include "utils/snapmgr.h"
                                108                 : #include "utils/syscache.h"
                                109                 : #include "utils/timeout.h"
                                110                 : #include "utils/timestamp.h"
                                111                 : 
                                112                 : 
                                113                 : /*
                                114                 :  * GUC parameters
                                115                 :  */
                                116                 : bool        autovacuum_start_daemon = false;
                                117                 : int         autovacuum_max_workers;
                                118                 : int         autovacuum_work_mem = -1;
                                119                 : int         autovacuum_naptime;
                                120                 : int         autovacuum_vac_thresh;
                                121                 : double      autovacuum_vac_scale;
                                122                 : int         autovacuum_vac_ins_thresh;
                                123                 : double      autovacuum_vac_ins_scale;
                                124                 : int         autovacuum_anl_thresh;
                                125                 : double      autovacuum_anl_scale;
                                126                 : int         autovacuum_freeze_max_age;
                                127                 : int         autovacuum_multixact_freeze_max_age;
                                128                 : 
                                129                 : double      autovacuum_vac_cost_delay;
                                130                 : int         autovacuum_vac_cost_limit;
                                131                 : 
                                132                 : int         Log_autovacuum_min_duration = 600000;
                                133                 : 
                                134                 : /* the minimum allowed time between two awakenings of the launcher */
                                135                 : #define MIN_AUTOVAC_SLEEPTIME 100.0 /* milliseconds */
                                136                 : #define MAX_AUTOVAC_SLEEPTIME 300   /* seconds */
                                137                 : 
                                138                 : /* Flags to tell if we are in an autovacuum process */
                                139                 : static bool am_autovacuum_launcher = false;
                                140                 : static bool am_autovacuum_worker = false;
                                141                 : 
                                142                 : /*
                                143                 :  * Variables to save the cost-related storage parameters for the current
                                144                 :  * relation being vacuumed by this autovacuum worker. Using these, we can
                                145                 :  * ensure we don't overwrite the values of vacuum_cost_delay and
                                146                 :  * vacuum_cost_limit after reloading the configuration file. They are
                                147                 :  * initialized to "invalid" values to indicate that no cost-related storage
                                148                 :  * parameters were specified and will be set in do_autovacuum() after checking
                                149                 :  * the storage parameters in table_recheck_autovac().
                                150                 :  */
                                151                 : static double av_storage_param_cost_delay = -1;
                                152                 : static int  av_storage_param_cost_limit = -1;
                                153                 : 
                                154                 : /* Flags set by signal handlers */
                                155                 : static volatile sig_atomic_t got_SIGUSR2 = false;
                                156                 : 
                                157                 : /* Comparison points for determining whether freeze_max_age is exceeded */
                                158                 : static TransactionId recentXid;
                                159                 : static MultiXactId recentMulti;
                                160                 : 
                                161                 : /* Default freeze ages to use for autovacuum (varies by database) */
                                162                 : static int  default_freeze_min_age;
                                163                 : static int  default_freeze_table_age;
                                164                 : static int  default_multixact_freeze_min_age;
                                165                 : static int  default_multixact_freeze_table_age;
                                166                 : 
                                167                 : /* Memory context for long-lived data */
                                168                 : static MemoryContext AutovacMemCxt;
                                169                 : 
                                170                 : /* struct to keep track of databases in launcher */
                                171                 : typedef struct avl_dbase
                                172                 : {
                                173                 :     Oid         adl_datid;      /* hash key -- must be first */
                                174                 :     TimestampTz adl_next_worker;
                                175                 :     int         adl_score;
                                176                 :     dlist_node  adl_node;
                                177                 : } avl_dbase;
                                178                 : 
                                179                 : /* struct to keep track of databases in worker */
                                180                 : typedef struct avw_dbase
                                181                 : {
                                182                 :     Oid         adw_datid;
                                183                 :     char       *adw_name;
                                184                 :     TransactionId adw_frozenxid;
                                185                 :     MultiXactId adw_minmulti;
                                186                 :     PgStat_StatDBEntry *adw_entry;
                                187                 : } avw_dbase;
                                188                 : 
                                189                 : /* struct to keep track of tables to vacuum and/or analyze, in 1st pass */
                                190                 : typedef struct av_relation
                                191                 : {
                                192                 :     Oid         ar_toastrelid;  /* hash key - must be first */
                                193                 :     Oid         ar_relid;
                                194                 :     bool        ar_hasrelopts;
                                195                 :     AutoVacOpts ar_reloptions;  /* copy of AutoVacOpts from the main table's
                                196                 :                                  * reloptions, or NULL if none */
                                197                 : } av_relation;
                                198                 : 
                                199                 : /* struct to keep track of tables to vacuum and/or analyze, after rechecking */
                                200                 : typedef struct autovac_table
                                201                 : {
                                202                 :     Oid         at_relid;
                                203                 :     VacuumParams at_params;
                                204                 :     double      at_storage_param_vac_cost_delay;
                                205                 :     int         at_storage_param_vac_cost_limit;
                                206                 :     bool        at_dobalance;
                                207                 :     bool        at_sharedrel;
                                208                 :     char       *at_relname;
                                209                 :     char       *at_nspname;
                                210                 :     char       *at_datname;
                                211                 : } autovac_table;
                                212                 : 
                                213                 : /*-------------
                                214                 :  * This struct holds information about a single worker's whereabouts.  We keep
                                215                 :  * an array of these in shared memory, sized according to
                                216                 :  * autovacuum_max_workers.
                                217                 :  *
                                218                 :  * wi_links     entry into free list or running list
                                219                 :  * wi_dboid     OID of the database this worker is supposed to work on
                                220                 :  * wi_tableoid  OID of the table currently being vacuumed, if any
                                221                 :  * wi_sharedrel flag indicating whether table is marked relisshared
                                222                 :  * wi_proc      pointer to PGPROC of the running worker, NULL if not started
                                223                 :  * wi_launchtime Time at which this worker was launched
                                224                 :  * wi_dobalance Whether this worker should be included in balance calculations
                                225                 :  *
                                226                 :  * All fields are protected by AutovacuumLock, except for wi_tableoid and
                                227                 :  * wi_sharedrel which are protected by AutovacuumScheduleLock (note these
                                228                 :  * two fields are read-only for everyone except that worker itself).
                                229                 :  *-------------
                                230                 :  */
                                231                 : typedef struct WorkerInfoData
                                232                 : {
                                233                 :     dlist_node  wi_links;
                                234                 :     Oid         wi_dboid;
                                235                 :     Oid         wi_tableoid;
                                236                 :     PGPROC     *wi_proc;
                                237                 :     TimestampTz wi_launchtime;
                                238                 :     pg_atomic_flag wi_dobalance;
                                239                 :     bool        wi_sharedrel;
                                240                 : } WorkerInfoData;
                                241                 : 
                                242                 : typedef struct WorkerInfoData *WorkerInfo;
                                243                 : 
                                244                 : /*
                                245                 :  * Possible signals received by the launcher from remote processes.  These are
                                246                 :  * stored atomically in shared memory so that other processes can set them
                                247                 :  * without locking.
                                248                 :  */
                                249                 : typedef enum
                                250                 : {
                                251                 :     AutoVacForkFailed,          /* failed trying to start a worker */
                                252                 :     AutoVacRebalance,           /* rebalance the cost limits */
                                253                 :     AutoVacNumSignals           /* must be last */
                                254                 : }           AutoVacuumSignal;
                                255                 : 
                                256                 : /*
                                257                 :  * Autovacuum workitem array, stored in AutoVacuumShmem->av_workItems.  This
                                258                 :  * list is mostly protected by AutovacuumLock, except that if an item is
                                259                 :  * marked 'active' other processes must not modify the work-identifying
                                260                 :  * members.
                                261                 :  */
                                262                 : typedef struct AutoVacuumWorkItem
                                263                 : {
                                264                 :     AutoVacuumWorkItemType avw_type;
                                265                 :     bool        avw_used;       /* below data is valid */
                                266                 :     bool        avw_active;     /* being processed */
                                267                 :     Oid         avw_database;
                                268                 :     Oid         avw_relation;
                                269                 :     BlockNumber avw_blockNumber;
                                270                 : } AutoVacuumWorkItem;
                                271                 : 
                                272                 : #define NUM_WORKITEMS   256
                                273                 : 
                                274                 : /*-------------
                                275                 :  * The main autovacuum shmem struct.  On shared memory we store this main
                                276                 :  * struct and the array of WorkerInfo structs.  This struct keeps:
                                277                 :  *
                                278                 :  * av_signal        set by other processes to indicate various conditions
                                279                 :  * av_launcherpid   the PID of the autovacuum launcher
                                280                 :  * av_freeWorkers   the WorkerInfo freelist
                                281                 :  * av_runningWorkers the WorkerInfo non-free queue
                                282                 :  * av_startingWorker pointer to WorkerInfo currently being started (cleared by
                                283                 :  *                  the worker itself as soon as it's up and running)
                                284                 :  * av_workItems     work item array
                                285                 :  * av_nworkersForBalance the number of autovacuum workers to use when
                                286                 :  *                  calculating the per worker cost limit
                                287                 :  *
                                288                 :  * This struct is protected by AutovacuumLock, except for av_signal and parts
                                289                 :  * of the worker list (see above).
                                290                 :  *-------------
                                291                 :  */
                                292                 : typedef struct
                                293                 : {
                                294                 :     sig_atomic_t av_signal[AutoVacNumSignals];
                                295                 :     pid_t       av_launcherpid;
                                296                 :     dlist_head  av_freeWorkers;
                                297                 :     dlist_head  av_runningWorkers;
                                298                 :     WorkerInfo  av_startingWorker;
                                299                 :     AutoVacuumWorkItem av_workItems[NUM_WORKITEMS];
                                300                 :     pg_atomic_uint32 av_nworkersForBalance;
                                301                 : } AutoVacuumShmemStruct;
                                302                 : 
                                303                 : static AutoVacuumShmemStruct *AutoVacuumShmem;
                                304                 : 
                                305                 : /*
                                306                 :  * the database list (of avl_dbase elements) in the launcher, and the context
                                307                 :  * that contains it
                                308                 :  */
                                309                 : static dlist_head DatabaseList = DLIST_STATIC_INIT(DatabaseList);
                                310                 : static MemoryContext DatabaseListCxt = NULL;
                                311                 : 
                                312                 : /* Pointer to my own WorkerInfo, valid on each worker */
                                313                 : static WorkerInfo MyWorkerInfo = NULL;
                                314                 : 
                                315                 : /* PID of launcher, valid only in worker while shutting down */
                                316                 : int         AutovacuumLauncherPid = 0;
                                317                 : 
                                318                 : #ifdef EXEC_BACKEND
                                319                 : static pid_t avlauncher_forkexec(void);
                                320                 : static pid_t avworker_forkexec(void);
                                321                 : #endif
                                322                 : NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]) pg_attribute_noreturn();
                                323                 : NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]) pg_attribute_noreturn();
                                324                 : 
                                325                 : static Oid  do_start_worker(void);
                                326                 : static void HandleAutoVacLauncherInterrupts(void);
                                327                 : static void AutoVacLauncherShutdown(void) pg_attribute_noreturn();
                                328                 : static void launcher_determine_sleep(bool canlaunch, bool recursing,
                                329                 :                                      struct timeval *nap);
                                330                 : static void launch_worker(TimestampTz now);
                                331                 : static List *get_database_list(void);
                                332                 : static void rebuild_database_list(Oid newdb);
                                333                 : static int  db_comparator(const void *a, const void *b);
                                334                 : static void autovac_recalculate_workers_for_balance(void);
                                335                 : 
                                336                 : static void do_autovacuum(void);
                                337                 : static void FreeWorkerInfo(int code, Datum arg);
                                338                 : 
                                339                 : static autovac_table *table_recheck_autovac(Oid relid, HTAB *table_toast_map,
                                340                 :                                             TupleDesc pg_class_desc,
                                341                 :                                             int effective_multixact_freeze_max_age);
                                342                 : static void recheck_relation_needs_vacanalyze(Oid relid, AutoVacOpts *avopts,
                                343                 :                                               Form_pg_class classForm,
                                344                 :                                               int effective_multixact_freeze_max_age,
                                345                 :                                               bool *dovacuum, bool *doanalyze, bool *wraparound);
                                346                 : static void relation_needs_vacanalyze(Oid relid, AutoVacOpts *relopts,
                                347                 :                                       Form_pg_class classForm,
                                348                 :                                       PgStat_StatTabEntry *tabentry,
                                349                 :                                       int effective_multixact_freeze_max_age,
                                350                 :                                       bool *dovacuum, bool *doanalyze, bool *wraparound);
                                351                 : 
                                352                 : static void autovacuum_do_vac_analyze(autovac_table *tab,
                                353                 :                                       BufferAccessStrategy bstrategy);
                                354                 : static AutoVacOpts *extract_autovac_opts(HeapTuple tup,
                                355                 :                                          TupleDesc pg_class_desc);
                                356                 : static void perform_work_item(AutoVacuumWorkItem *workitem);
                                357                 : static void autovac_report_activity(autovac_table *tab);
                                358                 : static void autovac_report_workitem(AutoVacuumWorkItem *workitem,
                                359                 :                                     const char *nspname, const char *relname);
                                360                 : static void avl_sigusr2_handler(SIGNAL_ARGS);
                                361                 : 
                                362                 : 
                                363                 : 
                                364                 : /********************************************************************
                                365                 :  *                    AUTOVACUUM LAUNCHER CODE
                                366                 :  ********************************************************************/
                                367                 : 
                                368                 : #ifdef EXEC_BACKEND
                                369                 : /*
                                370                 :  * forkexec routine for the autovacuum launcher process.
                                371                 :  *
                                372                 :  * Format up the arglist, then fork and exec.
                                373                 :  */
                                374                 : static pid_t
                                375                 : avlauncher_forkexec(void)
                                376                 : {
                                377                 :     char       *av[10];
                                378                 :     int         ac = 0;
                                379                 : 
                                380                 :     av[ac++] = "postgres";
                                381                 :     av[ac++] = "--forkavlauncher";
                                382                 :     av[ac++] = NULL;            /* filled in by postmaster_forkexec */
                                383                 :     av[ac] = NULL;
                                384                 : 
                                385                 :     Assert(ac < lengthof(av));
                                386                 : 
                                387                 :     return postmaster_forkexec(ac, av);
                                388                 : }
                                389                 : 
                                390                 : /*
                                391                 :  * We need this set from the outside, before InitProcess is called
                                392                 :  */
                                393                 : void
                                394                 : AutovacuumLauncherIAm(void)
                                395                 : {
                                396                 :     am_autovacuum_launcher = true;
                                397                 : }
                                398                 : #endif
                                399                 : 
                                400                 : /*
                                401                 :  * Main entry point for autovacuum launcher process, to be called from the
                                402                 :  * postmaster.
                                403                 :  */
                                404                 : int
 5897 alvherre                  405 GIC         493 : StartAutoVacLauncher(void)
                                406                 : {
                                407                 :     pid_t       AutoVacPID;
                                408                 : 
                                409                 : #ifdef EXEC_BACKEND
                                410                 :     switch ((AutoVacPID = avlauncher_forkexec()))
                                411                 : #else
 6385 bruce                     412             493 :     switch ((AutoVacPID = fork_process()))
                                413                 : #endif
                                414                 :     {
 6478 tgl                       415 UIC           0 :         case -1:
                                416               0 :             ereport(LOG,
                                417                 :                     (errmsg("could not fork autovacuum launcher process: %m")));
 6478 tgl                       418 LBC           0 :             return 0;
                                419                 : 
                                420                 : #ifndef EXEC_BACKEND
 6478 tgl                       421 GIC         306 :         case 0:
                                422                 :             /* in postmaster child ... */
 3008 andres                    423             306 :             InitPostmasterChild();
                                424                 : 
 6478 tgl                       425 ECB             :             /* Close the postmaster's sockets */
 6478 tgl                       426 GIC         306 :             ClosePostmasterPorts(false);
                                427                 : 
 5897 alvherre                  428 GBC         306 :             AutoVacLauncherMain(0, NULL);
 6478 tgl                       429 EUB             :             break;
                                430                 : #endif
 6478 tgl                       431 GBC         493 :         default:
 6478 tgl                       432 GIC         493 :             return (int) AutoVacPID;
                                433                 :     }
 6478 tgl                       434 ECB             : 
                                435                 :     /* shouldn't get here */
                                436                 :     return 0;
                                437                 : }
                                438                 : 
                                439                 : /*
                                440                 :  * Main loop for the autovacuum launcher process.
                                441                 :  */
                                442                 : NON_EXEC_STATIC void
 5897 alvherre                  443 GIC         306 : AutoVacLauncherMain(int argc, char *argv[])
 6478 tgl                       444 ECB             : {
 5897 alvherre                  445                 :     sigjmp_buf  local_sigjmp_buf;
                                446                 : 
 5897 alvherre                  447 GIC         306 :     am_autovacuum_launcher = true;
                                448                 : 
 1124 peter                     449             306 :     MyBackendType = B_AUTOVAC_LAUNCHER;
                                450             306 :     init_ps_display(NULL);
                                451                 : 
 2221 tgl                       452             306 :     ereport(DEBUG1,
                                453                 :             (errmsg_internal("autovacuum launcher started")));
                                454                 : 
 5646 alvherre                  455             306 :     if (PostAuthDelay)
 5646 alvherre                  456 LBC           0 :         pg_usleep(PostAuthDelay * 1000000L);
                                457                 : 
 5897 alvherre                  458 GIC         306 :     SetProcessingMode(InitProcessing);
                                459                 : 
 5897 alvherre                  460 ECB             :     /*
                                461                 :      * Set up signal handlers.  We operate on databases much like a regular
 4969 tgl                       462                 :      * backend, so we use the same signal handling.  See equivalent code in
                                463                 :      * tcop/postgres.c.
                                464                 :      */
 1209 rhaas                     465 CBC         306 :     pqsignal(SIGHUP, SignalHandlerForConfigReload);
 4969 tgl                       466 GIC         306 :     pqsignal(SIGINT, StatementCancelHandler);
 1209 rhaas                     467             306 :     pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
  935 tgl                       468 ECB             :     /* SIGQUIT handler was already set up by InitPostmasterChild */
 4969 tgl                       469 EUB             : 
 3919 alvherre                  470 GIC         306 :     InitializeTimeouts();       /* establishes SIGALRM handler */
 5897 alvherre                  471 ECB             : 
 5897 alvherre                  472 GIC         306 :     pqsignal(SIGPIPE, SIG_IGN);
 4969 tgl                       473             306 :     pqsignal(SIGUSR1, procsignal_sigusr1_handler);
                                474             306 :     pqsignal(SIGUSR2, avl_sigusr2_handler);
 5897 alvherre                  475             306 :     pqsignal(SIGFPE, FloatExceptionHandler);
                                476             306 :     pqsignal(SIGCHLD, SIG_DFL);
                                477                 : 
 5897 alvherre                  478 ECB             :     /*
                                479                 :      * Create a per-backend PGPROC struct in shared memory, except in the
                                480                 :      * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
                                481                 :      * this before we can use LWLocks (and in the EXEC_BACKEND case we already
                                482                 :      * had to do some stuff with LWLocks).
                                483                 :      */
                                484                 : #ifndef EXEC_BACKEND
 4969 tgl                       485 CBC         306 :     InitProcess();
 5897 alvherre                  486 ECB             : #endif
                                487                 : 
  612 andres                    488                 :     /* Early initialization */
  612 andres                    489 CBC         306 :     BaseInit();
                                490                 : 
  258 tgl                       491 GIC         306 :     InitPostgres(NULL, InvalidOid, NULL, InvalidOid, false, false, NULL);
                                492                 : 
 4969                           493             306 :     SetProcessingMode(NormalProcessing);
                                494                 : 
                                495                 :     /*
                                496                 :      * Create a memory context that we will do all our work in.  We do this so
                                497                 :      * that we can reset the context during error recovery and thereby avoid
 5897 alvherre                  498 ECB             :      * possible memory leaks.
                                499                 :      */
 5837 alvherre                  500 GIC         306 :     AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
                                501                 :                                           "Autovacuum Launcher",
 2416 tgl                       502 ECB             :                                           ALLOCSET_DEFAULT_SIZES);
 5837 alvherre                  503 GIC         306 :     MemoryContextSwitchTo(AutovacMemCxt);
 5897 alvherre                  504 ECB             : 
                                505                 :     /*
                                506                 :      * If an exception is encountered, processing resumes here.
                                507                 :      *
                                508                 :      * This code is a stripped down version of PostgresMain error recovery.
                                509                 :      *
                                510                 :      * Note that we use sigsetjmp(..., 1), so that the prevailing signal mask
                                511                 :      * (to wit, BlockSig) will be restored when longjmp'ing to here.  Thus,
                                512                 :      * signals other than SIGQUIT will be blocked until we complete error
  935 tgl                       513                 :      * recovery.  It might seem that this policy makes the HOLD_INTERRUPTS()
                                514                 :      * call redundant, but it is not since InterruptPending might be set
                                515                 :      * already.
 5897 alvherre                  516                 :      */
 5897 alvherre                  517 GIC         306 :     if (sigsetjmp(local_sigjmp_buf, 1) != 0)
                                518                 :     {
                                519                 :         /* since not using PG_TRY, must reset error stack by hand */
 5897 alvherre                  520 UIC           0 :         error_context_stack = NULL;
                                521                 : 
                                522                 :         /* Prevents interrupts while cleaning up */
                                523               0 :         HOLD_INTERRUPTS();
                                524                 : 
                                525                 :         /* Forget any pending QueryCancel or timeout request */
 3919                           526               0 :         disable_all_timeouts(false);
 2118 tgl                       527               0 :         QueryCancelPending = false; /* second to avoid race condition */
                                528                 : 
                                529                 :         /* Report the error to the server log */
 5897 alvherre                  530 LBC           0 :         EmitErrorReport();
                                531                 : 
                                532                 :         /* Abort the current transaction in order to recover */
 4969 tgl                       533 UBC           0 :         AbortCurrentTransaction();
                                534                 : 
                                535                 :         /*
 2063 alvherre                  536 EUB             :          * Release any other resources, for the case where we were not in a
                                537                 :          * transaction.
                                538                 :          */
 2063 alvherre                  539 UBC           0 :         LWLockReleaseAll();
                                540               0 :         pgstat_report_wait_end();
 2063 alvherre                  541 UIC           0 :         UnlockBuffers();
 1726 tgl                       542 EUB             :         /* this is probably dead code, but let's be safe: */
 1726 tgl                       543 UIC           0 :         if (AuxProcessResourceOwner)
                                544               0 :             ReleaseAuxProcessResources(false);
 2063 alvherre                  545 UBC           0 :         AtEOXact_Buffers(false);
 2063 alvherre                  546 UIC           0 :         AtEOXact_SMgr();
 1807 tgl                       547               0 :         AtEOXact_Files(false);
 2063 alvherre                  548               0 :         AtEOXact_HashTables(false);
                                549                 : 
                                550                 :         /*
 5897 alvherre                  551 EUB             :          * Now return to normal top-level context and clear ErrorContext for
                                552                 :          * next time.
                                553                 :          */
 5837 alvherre                  554 UIC           0 :         MemoryContextSwitchTo(AutovacMemCxt);
 5897 alvherre                  555 UBC           0 :         FlushErrorState();
 5897 alvherre                  556 EUB             : 
                                557                 :         /* Flush any leaked data in the top-level context */
 5837 alvherre                  558 UBC           0 :         MemoryContextResetAndDeleteChildren(AutovacMemCxt);
 5837 alvherre                  559 EUB             : 
                                560                 :         /* don't leave dangling pointers to freed memory */
 5837 alvherre                  561 UIC           0 :         DatabaseListCxt = NULL;
 3827                           562               0 :         dlist_init(&DatabaseList);
                                563                 : 
                                564                 :         /* Now we can allow interrupts again */
 5897                           565               0 :         RESUME_INTERRUPTS();
 5897 alvherre                  566 EUB             : 
 2923                           567                 :         /* if in shutdown mode, no need for anything further; just go away */
 1209 rhaas                     568 UIC           0 :         if (ShutdownRequestPending)
                                569               0 :             AutoVacLauncherShutdown();
 2923 alvherre                  570 EUB             : 
                                571                 :         /*
                                572                 :          * Sleep at least 1 second after any error.  We don't want to be
 5897                           573                 :          * filling the error logs as fast as we can.
                                574                 :          */
 5897 alvherre                  575 UIC           0 :         pg_usleep(1000000L);
                                576                 :     }
 5897 alvherre                  577 EUB             : 
                                578                 :     /* We can now handle ereport(ERROR) */
 5897 alvherre                  579 GIC         306 :     PG_exception_stack = &local_sigjmp_buf;
 5897 alvherre                  580 EUB             : 
 5837                           581                 :     /* must unblock signals before calling rebuild_database_list */
   65 tmunro                    582 GNC         306 :     sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
                                583                 : 
                                584                 :     /*
                                585                 :      * Set always-secure search path.  Launcher doesn't connect to a database,
                                586                 :      * so this has no effect.
 1868 noah                      587 EUB             :      */
 1868 noah                      588 GIC         306 :     SetConfigOption("search_path", "", PGC_SUSET, PGC_S_OVERRIDE);
                                589                 : 
                                590                 :     /*
 4149 tgl                       591 ECB             :      * Force zero_damaged_pages OFF in the autovac process, even if it is set
                                592                 :      * in postgresql.conf.  We don't really want such a dangerous option being
                                593                 :      * applied non-interactively.
                                594                 :      */
 4149 tgl                       595 GIC         306 :     SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
                                596                 : 
                                597                 :     /*
                                598                 :      * Force settable timeouts off to avoid letting these settings prevent
                                599                 :      * regular maintenance from being executed.
 4149 tgl                       600 ECB             :      */
 4149 tgl                       601 GIC         306 :     SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
 3676                           602             306 :     SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
 2489                           603             306 :     SetConfigOption("idle_in_transaction_session_timeout", "0",
                                604                 :                     PGC_SUSET, PGC_S_OVERRIDE);
                                605                 : 
                                606                 :     /*
 3955 bruce                     607 ECB             :      * Force default_transaction_isolation to READ COMMITTED.  We don't want
                                608                 :      * to pay the overhead of serializable mode, nor add any risk of causing
                                609                 :      * deadlocks or delaying other transactions.
                                610                 :      */
 4149 tgl                       611 GIC         306 :     SetConfigOption("default_transaction_isolation", "read committed",
                                612                 :                     PGC_SUSET, PGC_S_OVERRIDE);
 4149 tgl                       613 ECB             : 
  368 andres                    614                 :     /*
                                615                 :      * Even when system is configured to use a different fetch consistency,
                                616                 :      * for autovac we always want fresh stats.
                                617                 :      */
  368 andres                    618 GIC         306 :     SetConfigOption("stats_fetch_consistency", "none", PGC_SUSET, PGC_S_OVERRIDE);
                                619                 : 
                                620                 :     /*
                                621                 :      * In emergency mode, just start a worker (unless shutdown was requested)
                                622                 :      * and go away.
 2923 alvherre                  623 ECB             :      */
 5676 tgl                       624 GIC         306 :     if (!AutoVacuumingActive())
                                625                 :     {
 1209 rhaas                     626 UIC           0 :         if (!ShutdownRequestPending)
 2923 alvherre                  627               0 :             do_start_worker();
 5624 bruce                     628               0 :         proc_exit(0);           /* done */
                                629                 :     }
 5837 alvherre                  630 ECB             : 
 5837 alvherre                  631 GIC         306 :     AutoVacuumShmem->av_launcherpid = MyProcPid;
                                632                 : 
                                633                 :     /*
                                634                 :      * Create the initial database list.  The invariant we want this list to
                                635                 :      * keep is that it's ordered by decreasing next_time.  As soon as an entry
 5837 alvherre                  636 ECB             :      * is updated to a higher time, it will be moved to the front (which is
                                637                 :      * correct because the only operation is to add autovacuum_naptime to the
 5837 alvherre                  638 EUB             :      * entry, and time always increases).
 5897                           639                 :      */
 5837 alvherre                  640 GBC         306 :     rebuild_database_list(InvalidOid);
                                641                 : 
                                642                 :     /* loop until shutdown request */
 1209 rhaas                     643 CBC        1620 :     while (!ShutdownRequestPending)
                                644                 :     {
                                645                 :         struct timeval nap;
 5837 alvherre                  646 GIC        1619 :         TimestampTz current_time = 0;
                                647                 :         bool        can_launch;
                                648                 : 
                                649                 :         /*
                                650                 :          * This loop is a bit different from the normal use of WaitLatch,
                                651                 :          * because we'd like to sleep before the first launch of a child
 4260 tgl                       652 ECB             :          * process.  So it's WaitLatch, then ResetLatch, then check for
                                653                 :          * wakening conditions.
                                654                 :          */
 5897 alvherre                  655                 : 
 3827 alvherre                  656 GIC        1619 :         launcher_determine_sleep(!dlist_is_empty(&AutoVacuumShmem->av_freeWorkers),
 5271 tgl                       657            1619 :                                  false, &nap);
 5779 alvherre                  658 ECB             : 
                                659                 :         /*
                                660                 :          * Wait until naptime expires or we get some type of signal (all the
                                661                 :          * signal handlers will wake us by calling SetLatch).
                                662                 :          */
 1598 tmunro                    663 GIC        1619 :         (void) WaitLatch(MyLatch,
                                664                 :                          WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
                                665            1619 :                          (nap.tv_sec * 1000L) + (nap.tv_usec / 1000L),
                                666                 :                          WAIT_EVENT_AUTOVACUUM_MAIN);
                                667                 : 
 3007 andres                    668 CBC        1616 :         ResetLatch(MyLatch);
 5837 alvherre                  669 ECB             : 
 1209 rhaas                     670 GIC        1616 :         HandleAutoVacLauncherInterrupts();
                                671                 : 
                                672                 :         /*
                                673                 :          * a worker finished, or postmaster signaled failure to start a worker
                                674                 :          */
 4969 tgl                       675 CBC        1314 :         if (got_SIGUSR2)
                                676                 :         {
                                677              32 :             got_SIGUSR2 = false;
                                678                 : 
                                679                 :             /* rebalance cost limits, if needed */
 5767 alvherre                  680              32 :             if (AutoVacuumShmem->av_signal[AutoVacRebalance])
                                681                 :             {
 5837                           682              16 :                 LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
 5767 alvherre                  683 GIC          16 :                 AutoVacuumShmem->av_signal[AutoVacRebalance] = false;
    2 dgustafsson               684 GNC          16 :                 autovac_recalculate_workers_for_balance();
 5837 alvherre                  685 GIC          16 :                 LWLockRelease(AutovacuumLock);
                                686                 :             }
 5767 alvherre                  687 ECB             : 
 5767 alvherre                  688 GIC          32 :             if (AutoVacuumShmem->av_signal[AutoVacForkFailed])
 5767 alvherre                  689 ECB             :             {
                                690                 :                 /*
                                691                 :                  * If the postmaster failed to start a new worker, we sleep
                                692                 :                  * for a little while and resend the signal.  The new worker's
                                693                 :                  * state is still in memory, so this is sufficient.  After
                                694                 :                  * that, we restart the main loop.
                                695                 :                  *
                                696                 :                  * XXX should we put a limit to the number of times we retry?
                                697                 :                  * I don't think it makes much sense, because a future start
                                698                 :                  * of a worker will continue to fail in the same way.
                                699                 :                  */
 5767 alvherre                  700 LBC           0 :                 AutoVacuumShmem->av_signal[AutoVacForkFailed] = false;
 4790 bruce                     701 UIC           0 :                 pg_usleep(1000000L);    /* 1s */
 5767 alvherre                  702               0 :                 SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
                                703               0 :                 continue;
                                704                 :             }
                                705                 :         }
                                706                 : 
                                707                 :         /*
                                708                 :          * There are some conditions that we need to check before trying to
                                709                 :          * start a worker.  First, we need to make sure that there is a worker
                                710                 :          * slot available.  Second, we need to make sure that no other worker
                                711                 :          * failed while starting up.
 5897 alvherre                  712 EUB             :          */
 5837                           713                 : 
 5767 alvherre                  714 GBC        1314 :         current_time = GetCurrentTimestamp();
 5897                           715            1314 :         LWLockAcquire(AutovacuumLock, LW_SHARED);
                                716                 : 
 3827 alvherre                  717 GIC        1314 :         can_launch = !dlist_is_empty(&AutoVacuumShmem->av_freeWorkers);
                                718                 : 
 5271 tgl                       719            1314 :         if (AutoVacuumShmem->av_startingWorker != NULL)
                                720                 :         {
                                721                 :             int         waittime;
 5271 tgl                       722 UIC           0 :             WorkerInfo  worker = AutoVacuumShmem->av_startingWorker;
                                723                 : 
                                724                 :             /*
                                725                 :              * We can't launch another worker when another one is still
 5767 alvherre                  726 ECB             :              * starting up (or failed while doing so), so just sleep for a bit
                                727                 :              * more; that worker will wake us up again as soon as it's ready.
                                728                 :              * We will only wait autovacuum_naptime seconds (up to a maximum
 5624 bruce                     729                 :              * of 60 seconds) for this to happen however.  Note that failure
                                730                 :              * to connect to a particular database is not a problem here,
                                731                 :              * because the worker removes itself from the startingWorker
                                732                 :              * pointer before trying to connect.  Problems detected by the
                                733                 :              * postmaster (like fork() failure) are also reported and handled
 5624 bruce                     734 EUB             :              * differently.  The only problems that may cause this code to
                                735                 :              * fire are errors in the earlier sections of AutoVacWorkerMain,
                                736                 :              * before the worker removes the WorkerInfo from the
                                737                 :              * startingWorker pointer.
                                738                 :              */
 5767 alvherre                  739 UIC           0 :             waittime = Min(autovacuum_naptime, 60) * 1000;
 5821                           740               0 :             if (TimestampDifferenceExceeds(worker->wi_launchtime, current_time,
                                741                 :                                            waittime))
                                742                 :             {
 5837                           743               0 :                 LWLockRelease(AutovacuumLock);
                                744               0 :                 LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
                                745                 : 
                                746                 :                 /*
                                747                 :                  * No other process can put a worker in starting mode, so if
                                748                 :                  * startingWorker is still INVALID after exchanging our lock,
                                749                 :                  * we assume it's the same one we saw above (so we don't
                                750                 :                  * recheck the launch time).
 5837 alvherre                  751 EUB             :                  */
 5271 tgl                       752 UBC           0 :                 if (AutoVacuumShmem->av_startingWorker != NULL)
                                753                 :                 {
 5271 tgl                       754 UIC           0 :                     worker = AutoVacuumShmem->av_startingWorker;
 5837 alvherre                  755 UBC           0 :                     worker->wi_dboid = InvalidOid;
                                756               0 :                     worker->wi_tableoid = InvalidOid;
 2525 alvherre                  757 UIC           0 :                     worker->wi_sharedrel = false;
 5646                           758               0 :                     worker->wi_proc = NULL;
 5837                           759               0 :                     worker->wi_launchtime = 0;
 3825 tgl                       760               0 :                     dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
                                761                 :                                     &worker->wi_links);
 5271                           762               0 :                     AutoVacuumShmem->av_startingWorker = NULL;
  503 alvherre                  763               0 :                     ereport(WARNING,
  503 alvherre                  764 EUB             :                             errmsg("autovacuum worker took too long to start; canceled"));
                                765                 :                 }
 5837                           766                 :             }
 5897                           767                 :             else
 5837 alvherre                  768 UBC           0 :                 can_launch = false;
 5897 alvherre                  769 EUB             :         }
 5624 bruce                     770 GBC        1314 :         LWLockRelease(AutovacuumLock);  /* either shared or exclusive */
 5897 alvherre                  771 EUB             : 
 5767                           772                 :         /* if we can't do anything, just go back to sleep */
 5767 alvherre                  773 GIC        1314 :         if (!can_launch)
 5767 alvherre                  774 UBC           0 :             continue;
 5897 alvherre                  775 EUB             : 
                                776                 :         /* We're OK to start a new worker */
                                777                 : 
 3827 alvherre                  778 GIC        1314 :         if (dlist_is_empty(&DatabaseList))
                                779                 :         {
 5767 alvherre                  780 EUB             :             /*
                                781                 :              * Special case when the list is empty: start a worker right away.
 5767 alvherre                  782 ECB             :              * This covers the initial case, when no database is in pgstats
                                783                 :              * (thus the list is empty).  Note that the constraints in
                                784                 :              * launcher_determine_sleep keep us from starting workers too
                                785                 :              * quickly (at most once every autovacuum_naptime when the list is
 5767 alvherre                  786 EUB             :              * empty).
                                787                 :              */
 5767 alvherre                  788 GIC          24 :             launch_worker(current_time);
                                789                 :         }
 3827 alvherre                  790 ECB             :         else
                                791                 :         {
                                792                 :             /*
                                793                 :              * because rebuild_database_list constructs a list with most
                                794                 :              * distant adl_next_worker first, we obtain our database from the
                                795                 :              * tail of the list.
                                796                 :              */
                                797                 :             avl_dbase  *avdb;
                                798                 : 
 3827 alvherre                  799 GIC        1290 :             avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
 3827 alvherre                  800 ECB             : 
                                801                 :             /*
                                802                 :              * launch a worker if next_worker is right now or it is in the
                                803                 :              * past
                                804                 :              */
 3827 alvherre                  805 GIC        1290 :             if (TimestampDifferenceExceeds(avdb->adl_next_worker,
                                806                 :                                            current_time, 0))
                                807              16 :                 launch_worker(current_time);
                                808                 :         }
                                809                 :     }
                                810                 : 
 1209 rhaas                     811 CBC           1 :     AutoVacLauncherShutdown();
                                812                 : }
                                813                 : 
                                814                 : /*
                                815                 :  * Process any new interrupts.
                                816                 :  */
 1209 rhaas                     817 ECB             : static void
 1209 rhaas                     818 GIC        1616 : HandleAutoVacLauncherInterrupts(void)
 1209 rhaas                     819 ECB             : {
                                820                 :     /* the normal shutdown case */
 1209 rhaas                     821 GIC        1616 :     if (ShutdownRequestPending)
                                822             302 :         AutoVacLauncherShutdown();
 1209 rhaas                     823 ECB             : 
 1209 rhaas                     824 GIC        1314 :     if (ConfigReloadPending)
                                825                 :     {
                                826              25 :         ConfigReloadPending = false;
                                827              25 :         ProcessConfigFile(PGC_SIGHUP);
                                828                 : 
                                829                 :         /* shutdown requested in config file? */
 1209 rhaas                     830 CBC          25 :         if (!AutoVacuumingActive())
 1209 rhaas                     831 UIC           0 :             AutoVacLauncherShutdown();
                                832                 : 
 1209 rhaas                     833 ECB             :         /* rebuild the list in case the naptime changed */
 1209 rhaas                     834 CBC          25 :         rebuild_database_list(InvalidOid);
                                835                 :     }
                                836                 : 
 1207 rhaas                     837 ECB             :     /* Process barrier events */
 1207 rhaas                     838 GBC        1314 :     if (ProcSignalBarrierPending)
 1207 rhaas                     839 GIC          20 :         ProcessProcSignalBarrier();
                                840                 : 
  544 fujii                     841 ECB             :     /* Perform logging of memory contexts of this process */
  544 fujii                     842 GIC        1314 :     if (LogMemoryContextPending)
  544 fujii                     843 UIC           0 :         ProcessLogMemoryContextInterrupt();
                                844                 : 
 1209 rhaas                     845 ECB             :     /* Process sinval catchup interrupts that happened while sleeping */
 1209 rhaas                     846 CBC        1314 :     ProcessCatchupInterrupt();
 1209 rhaas                     847 GIC        1314 : }
                                848                 : 
 1209 rhaas                     849 ECB             : /*
 1209 rhaas                     850 EUB             :  * Perform a normal exit from the autovac launcher.
                                851                 :  */
                                852                 : static void
 1053 noah                      853 CBC         303 : AutoVacLauncherShutdown(void)
 1209 rhaas                     854 ECB             : {
 2221 tgl                       855 GIC         303 :     ereport(DEBUG1,
                                856                 :             (errmsg_internal("autovacuum launcher shutting down")));
 5837 alvherre                  857             303 :     AutoVacuumShmem->av_launcherpid = 0;
                                858                 : 
 5624 bruce                     859             303 :     proc_exit(0);               /* done */
 5897 alvherre                  860 ECB             : }
                                861                 : 
 5837                           862                 : /*
                                863                 :  * Determine the time to sleep, based on the database list.
                                864                 :  *
                                865                 :  * The "canlaunch" parameter indicates whether we can start a worker right now,
 5779                           866                 :  * for example due to the workers being all busy.  If this is false, we will
                                867                 :  * cause a long sleep, which will be interrupted when a worker exits.
                                868                 :  */
                                869                 : static void
 2118 tgl                       870 GIC        1619 : launcher_determine_sleep(bool canlaunch, bool recursing, struct timeval *nap)
                                871                 : {
                                872                 :     /*
                                873                 :      * We sleep until the next scheduled vacuum.  We trust that when the
                                874                 :      * database list was built, care was taken so that no entries have times
                                875                 :      * in the past; if the first entry has too close a next_worker value, or a
                                876                 :      * time in the past, we will sleep a small nominal time.
 5837 alvherre                  877 ECB             :      */
 5837 alvherre                  878 GIC        1619 :     if (!canlaunch)
                                879                 :     {
 5779 alvherre                  880 UIC           0 :         nap->tv_sec = autovacuum_naptime;
                                881               0 :         nap->tv_usec = 0;
                                882                 :     }
 3827 alvherre                  883 GIC        1619 :     else if (!dlist_is_empty(&DatabaseList))
                                884                 :     {
 5624 bruce                     885 CBC        1571 :         TimestampTz current_time = GetCurrentTimestamp();
                                886                 :         TimestampTz next_wakeup;
 3825 tgl                       887 EUB             :         avl_dbase  *avdb;
 5624 bruce                     888                 :         long        secs;
                                889                 :         int         usecs;
 5837 alvherre                  890 ECB             : 
 3827 alvherre                  891 GIC        1571 :         avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
 3827 alvherre                  892 ECB             : 
 5837 alvherre                  893 GIC        1571 :         next_wakeup = avdb->adl_next_worker;
                                894            1571 :         TimestampDifference(current_time, next_wakeup, &secs, &usecs);
                                895                 : 
 5779                           896            1571 :         nap->tv_sec = secs;
                                897            1571 :         nap->tv_usec = usecs;
 5837 alvherre                  898 ECB             :     }
                                899                 :     else
                                900                 :     {
                                901                 :         /* list is empty, sleep for whole autovacuum_naptime seconds  */
 5779 alvherre                  902 GIC          48 :         nap->tv_sec = autovacuum_naptime;
 5779 alvherre                  903 CBC          48 :         nap->tv_usec = 0;
 5837 alvherre                  904 ECB             :     }
                                905                 : 
                                906                 :     /*
                                907                 :      * If the result is exactly zero, it means a database had an entry with
                                908                 :      * time in the past.  Rebuild the list so that the databases are evenly
                                909                 :      * distributed again, and recalculate the time to sleep.  This can happen
                                910                 :      * if there are more tables needing vacuum than workers, and they all take
                                911                 :      * longer to vacuum than autovacuum_naptime.
                                912                 :      *
                                913                 :      * We only recurse once.  rebuild_database_list should always return times
                                914                 :      * in the future, but it seems best not to trust too much on that.
                                915                 :      */
 5761 tgl                       916 GIC        1619 :     if (nap->tv_sec == 0 && nap->tv_usec == 0 && !recursing)
                                917                 :     {
 5837 alvherre                  918 UIC           0 :         rebuild_database_list(InvalidOid);
 5779                           919               0 :         launcher_determine_sleep(canlaunch, true, nap);
                                920               0 :         return;
                                921                 :     }
                                922                 : 
 5052 alvherre                  923 ECB             :     /* The smallest time we'll allow the launcher to sleep. */
 5052 alvherre                  924 GIC        1619 :     if (nap->tv_sec <= 0 && nap->tv_usec <= MIN_AUTOVAC_SLEEPTIME * 1000)
 5837 alvherre                  925 EUB             :     {
 5761 tgl                       926 GBC           3 :         nap->tv_sec = 0;
 5052 alvherre                  927               3 :         nap->tv_usec = MIN_AUTOVAC_SLEEPTIME * 1000;
                                928                 :     }
                                929                 : 
                                930                 :     /*
 2851 alvherre                  931 ECB             :      * If the sleep time is too large, clamp it to an arbitrary maximum (plus
                                932                 :      * any fractional seconds, for simplicity).  This avoids an essentially
                                933                 :      * infinite sleep in strange cases like the system clock going backwards a
                                934                 :      * few years.
                                935                 :      */
 2851 alvherre                  936 GIC        1619 :     if (nap->tv_sec > MAX_AUTOVAC_SLEEPTIME)
                                937              11 :         nap->tv_sec = MAX_AUTOVAC_SLEEPTIME;
                                938                 : }
                                939                 : 
                                940                 : /*
                                941                 :  * Build an updated DatabaseList.  It must only contain databases that appear
                                942                 :  * in pgstats, and must be sorted by next_worker from highest to lowest,
 5837 alvherre                  943 ECB             :  * distributed regularly across the next autovacuum_naptime interval.
                                944                 :  *
                                945                 :  * Receives the Oid of the database that made this list be generated (we call
                                946                 :  * this the "new" database, because when the database was already present on
                                947                 :  * the list, we expect that this function is not called at all).  The
                                948                 :  * preexisting list, if any, will be used to preserve the order of the
                                949                 :  * databases in the autovacuum_naptime period.  The new database is put at the
                                950                 :  * end of the interval.  The actual values are not saved, which should not be
                                951                 :  * much of a problem.
                                952                 :  */
                                953                 : static void
 5837 alvherre                  954 GIC         337 : rebuild_database_list(Oid newdb)
                                955                 : {
                                956                 :     List       *dblist;
                                957                 :     ListCell   *cell;
                                958                 :     MemoryContext newcxt;
                                959                 :     MemoryContext oldcxt;
                                960                 :     MemoryContext tmpcxt;
 5837 alvherre                  961 ECB             :     HASHCTL     hctl;
                                962                 :     int         score;
                                963                 :     int         nelems;
                                964                 :     HTAB       *dbhash;
                                965                 :     dlist_iter  iter;
                                966                 : 
 5837 alvherre                  967 GIC         337 :     newcxt = AllocSetContextCreate(AutovacMemCxt,
                                968                 :                                    "Autovacuum database list",
                                969                 :                                    ALLOCSET_DEFAULT_SIZES);
                                970             337 :     tmpcxt = AllocSetContextCreate(newcxt,
                                971                 :                                    "Autovacuum database list (tmp)",
                                972                 :                                    ALLOCSET_DEFAULT_SIZES);
                                973             337 :     oldcxt = MemoryContextSwitchTo(tmpcxt);
 5837 alvherre                  974 ECB             : 
                                975                 :     /*
                                976                 :      * Implementing this is not as simple as it sounds, because we need to put
                                977                 :      * the new database at the end of the list; next the databases that were
                                978                 :      * already on the list, and finally (at the tail of the list) all the
                                979                 :      * other databases that are not on the existing list.
                                980                 :      *
                                981                 :      * To do this, we build an empty hash table of scored databases.  We will
                                982                 :      * start with the lowest score (zero) for the new database, then
                                983                 :      * increasing scores for the databases in the existing list, in order, and
                                984                 :      * lastly increasing scores for all databases gotten via
                                985                 :      * get_database_list() that are not already on the hash.
                                986                 :      *
                                987                 :      * Then we will put all the hash elements into an array, sort the array by
                                988                 :      * score, and finally put the array elements into the new doubly linked
                                989                 :      * list.
                                990                 :      */
 5837 alvherre                  991 GIC         337 :     hctl.keysize = sizeof(Oid);
                                992             337 :     hctl.entrysize = sizeof(avl_dbase);
                                993             337 :     hctl.hcxt = tmpcxt;
  332 tgl                       994             337 :     dbhash = hash_create("autovacuum db hash", 20, &hctl, /* magic number here
                                995                 :                                                              * FIXME */
                                996                 :                          HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
                                997                 : 
 5837 alvherre                  998 ECB             :     /* start by inserting the new database */
 5837 alvherre                  999 CBC         337 :     score = 0;
                               1000             337 :     if (OidIsValid(newdb))
 5837 alvherre                 1001 ECB             :     {
                               1002                 :         avl_dbase  *db;
                               1003                 :         PgStat_StatDBEntry *entry;
                               1004                 : 
                               1005                 :         /* only consider this database if it has a pgstat entry */
 5837 alvherre                 1006 CBC           6 :         entry = pgstat_fetch_stat_dbentry(newdb);
                               1007               6 :         if (entry != NULL)
                               1008                 :         {
                               1009                 :             /* we assume it isn't found because the hash was just created */
 5837 alvherre                 1010 GIC           6 :             db = hash_search(dbhash, &newdb, HASH_ENTER, NULL);
                               1011                 : 
                               1012                 :             /* hash_search already filled in the key */
 5837 alvherre                 1013 CBC           6 :             db->adl_score = score++;
 5837 alvherre                 1014 ECB             :             /* next_worker is filled in later */
                               1015                 :         }
                               1016                 :     }
                               1017                 : 
                               1018                 :     /* Now insert the databases from the existing list */
 3827 alvherre                 1019 GIC         381 :     dlist_foreach(iter, &DatabaseList)
 5837 alvherre                 1020 ECB             :     {
 3827 alvherre                 1021 GIC          44 :         avl_dbase  *avdb = dlist_container(avl_dbase, adl_node, iter.cur);
                               1022                 :         avl_dbase  *db;
                               1023                 :         bool        found;
                               1024                 :         PgStat_StatDBEntry *entry;
                               1025                 : 
 3827 alvherre                 1026 ECB             :         /*
                               1027                 :          * skip databases with no stat entries -- in particular, this gets rid
 3602 bruce                    1028                 :          * of dropped databases
                               1029                 :          */
 3827 alvherre                 1030 GIC          44 :         entry = pgstat_fetch_stat_dbentry(avdb->adl_datid);
                               1031              44 :         if (entry == NULL)
 3827 alvherre                 1032 UIC           0 :             continue;
                               1033                 : 
 3827 alvherre                 1034 GIC          44 :         db = hash_search(dbhash, &(avdb->adl_datid), HASH_ENTER, &found);
                               1035                 : 
                               1036              44 :         if (!found)
 3827 alvherre                 1037 ECB             :         {
                               1038                 :             /* hash_search already filled in the key */
 3827 alvherre                 1039 GBC          44 :             db->adl_score = score++;
                               1040                 :             /* next_worker is filled in later */
 5837 alvherre                 1041 ECB             :         }
                               1042                 :     }
                               1043                 : 
                               1044                 :     /* finally, insert all qualifying databases not previously inserted */
 5837 alvherre                 1045 GIC         337 :     dblist = get_database_list();
 5837 alvherre                 1046 CBC        1496 :     foreach(cell, dblist)
                               1047                 :     {
 5837 alvherre                 1048 GIC        1159 :         avw_dbase  *avdb = lfirst(cell);
                               1049                 :         avl_dbase  *db;
                               1050                 :         bool        found;
                               1051                 :         PgStat_StatDBEntry *entry;
 5837 alvherre                 1052 ECB             : 
                               1053                 :         /* only consider databases with a pgstat entry */
 5837 alvherre                 1054 GIC        1159 :         entry = pgstat_fetch_stat_dbentry(avdb->adw_datid);
 5837 alvherre                 1055 CBC        1159 :         if (entry == NULL)
 5837 alvherre                 1056 GIC         710 :             continue;
                               1057                 : 
                               1058             449 :         db = hash_search(dbhash, &(avdb->adw_datid), HASH_ENTER, &found);
                               1059                 :         /* only update the score if the database was not already on the hash */
                               1060             449 :         if (!found)
 5837 alvherre                 1061 ECB             :         {
                               1062                 :             /* hash_search already filled in the key */
 5837 alvherre                 1063 CBC         399 :             db->adl_score = score++;
                               1064                 :             /* next_worker is filled in later */
 5837 alvherre                 1065 ECB             :         }
                               1066                 :     }
 5837 alvherre                 1067 CBC         337 :     nelems = score;
                               1068                 : 
                               1069                 :     /* from here on, the allocated memory belongs to the new list */
                               1070             337 :     MemoryContextSwitchTo(newcxt);
 3827 alvherre                 1071 GIC         337 :     dlist_init(&DatabaseList);
                               1072                 : 
 5837                          1073             337 :     if (nelems > 0)
 5837 alvherre                 1074 ECB             :     {
                               1075                 :         TimestampTz current_time;
                               1076                 :         int         millis_increment;
 5624 bruce                    1077                 :         avl_dbase  *dbary;
                               1078                 :         avl_dbase  *db;
                               1079                 :         HASH_SEQ_STATUS seq;
                               1080                 :         int         i;
                               1081                 : 
                               1082                 :         /* put all the hash elements into an array */
 5837 alvherre                 1083 GIC         313 :         dbary = palloc(nelems * sizeof(avl_dbase));
                               1084                 : 
                               1085             313 :         i = 0;
                               1086             313 :         hash_seq_init(&seq, dbhash);
                               1087             762 :         while ((db = hash_seq_search(&seq)) != NULL)
                               1088             449 :             memcpy(&(dbary[i++]), db, sizeof(avl_dbase));
                               1089                 : 
 5837 alvherre                 1090 ECB             :         /* sort the array */
 5837 alvherre                 1091 GIC         313 :         qsort(dbary, nelems, sizeof(avl_dbase), db_comparator);
 5837 alvherre                 1092 ECB             : 
 5052                          1093                 :         /*
 5050 bruce                    1094                 :          * Determine the time interval between databases in the schedule. If
                               1095                 :          * we see that the configured naptime would take us to sleep times
                               1096                 :          * lower than our min sleep time (which launcher_determine_sleep is
                               1097                 :          * coded not to allow), silently use a larger naptime (but don't touch
 5052 alvherre                 1098                 :          * the GUC variable).
                               1099                 :          */
 5837 alvherre                 1100 GIC         313 :         millis_increment = 1000.0 * autovacuum_naptime / nelems;
 5052                          1101             313 :         if (millis_increment <= MIN_AUTOVAC_SLEEPTIME)
 5052 alvherre                 1102 UIC           0 :             millis_increment = MIN_AUTOVAC_SLEEPTIME * 1.1;
                               1103                 : 
 5837 alvherre                 1104 GIC         313 :         current_time = GetCurrentTimestamp();
                               1105                 : 
                               1106                 :         /*
 1371 michael                  1107 ECB             :          * move the elements from the array into the dlist, setting the
 5837 alvherre                 1108                 :          * next_worker while walking the array
 5837 alvherre                 1109 EUB             :          */
 5837 alvherre                 1110 GIC         762 :         for (i = 0; i < nelems; i++)
 5837 alvherre                 1111 ECB             :         {
  226 drowley                  1112 GNC         449 :             db = &(dbary[i]);
                               1113                 : 
 5837 alvherre                 1114 GIC         449 :             current_time = TimestampTzPlusMilliseconds(current_time,
                               1115                 :                                                        millis_increment);
                               1116             449 :             db->adl_next_worker = current_time;
 5837 alvherre                 1117 ECB             : 
                               1118                 :             /* later elements should go closer to the head of the list */
 3827 alvherre                 1119 CBC         449 :             dlist_push_head(&DatabaseList, &db->adl_node);
                               1120                 :         }
 5837 alvherre                 1121 ECB             :     }
                               1122                 : 
                               1123                 :     /* all done, clean up memory */
 5837 alvherre                 1124 GIC         337 :     if (DatabaseListCxt != NULL)
                               1125              31 :         MemoryContextDelete(DatabaseListCxt);
 5837 alvherre                 1126 CBC         337 :     MemoryContextDelete(tmpcxt);
 5837 alvherre                 1127 GIC         337 :     DatabaseListCxt = newcxt;
                               1128             337 :     MemoryContextSwitchTo(oldcxt);
                               1129             337 : }
                               1130                 : 
 5837 alvherre                 1131 ECB             : /* qsort comparator for avl_dbase, using adl_score */
                               1132                 : static int
 5837 alvherre                 1133 CBC         183 : db_comparator(const void *a, const void *b)
 5837 alvherre                 1134 ECB             : {
 4228 peter_e                  1135 CBC         183 :     if (((const avl_dbase *) a)->adl_score == ((const avl_dbase *) b)->adl_score)
 5837 alvherre                 1136 LBC           0 :         return 0;
                               1137                 :     else
 4228 peter_e                  1138 GIC         183 :         return (((const avl_dbase *) a)->adl_score < ((const avl_dbase *) b)->adl_score) ? 1 : -1;
                               1139                 : }
 5837 alvherre                 1140 ECB             : 
                               1141                 : /*
 5861                          1142                 :  * do_start_worker
 5861 alvherre                 1143 EUB             :  *
                               1144                 :  * Bare-bones procedure for starting an autovacuum worker from the launcher.
 5861 alvherre                 1145 ECB             :  * It determines what database to work on, sets up shared memory stuff and
                               1146                 :  * signals postmaster to start the worker.  It fails gracefully if invoked when
                               1147                 :  * autovacuum_workers are already active.
                               1148                 :  *
                               1149                 :  * Return value is the OID of the database that the worker is going to process,
                               1150                 :  * or InvalidOid if no worker was actually started.
                               1151                 :  */
                               1152                 : static Oid
 5861 alvherre                 1153 GIC          40 : do_start_worker(void)
                               1154                 : {
                               1155                 :     List       *dblist;
                               1156                 :     ListCell   *cell;
                               1157                 :     TransactionId xidForceLimit;
                               1158                 :     MultiXactId multiForceLimit;
                               1159                 :     bool        for_xid_wrap;
 3728 alvherre                 1160 ECB             :     bool        for_multi_wrap;
                               1161                 :     avw_dbase  *avdb;
                               1162                 :     TimestampTz current_time;
 5837 alvherre                 1163 GIC          40 :     bool        skipit = false;
 5688                          1164              40 :     Oid         retval = InvalidOid;
                               1165                 :     MemoryContext tmpcxt,
                               1166                 :                 oldcxt;
                               1167                 : 
                               1168                 :     /* return quickly when there are no free workers */
 5837                          1169              40 :     LWLockAcquire(AutovacuumLock, LW_SHARED);
 3827 alvherre                 1170 CBC          40 :     if (dlist_is_empty(&AutoVacuumShmem->av_freeWorkers))
 5837 alvherre                 1171 ECB             :     {
 5837 alvherre                 1172 UIC           0 :         LWLockRelease(AutovacuumLock);
                               1173               0 :         return InvalidOid;
                               1174                 :     }
 5837 alvherre                 1175 GIC          40 :     LWLockRelease(AutovacuumLock);
 5837 alvherre                 1176 ECB             : 
 5688                          1177                 :     /*
                               1178                 :      * Create and switch to a temporary context to avoid leaking the memory
 5688 alvherre                 1179 EUB             :      * allocated for the database list.
                               1180                 :      */
 5688 alvherre                 1181 GIC          40 :     tmpcxt = AllocSetContextCreate(CurrentMemoryContext,
  503 alvherre                 1182 ECB             :                                    "Autovacuum start worker (tmp)",
                               1183                 :                                    ALLOCSET_DEFAULT_SIZES);
 5688 alvherre                 1184 GIC          40 :     oldcxt = MemoryContextSwitchTo(tmpcxt);
                               1185                 : 
                               1186                 :     /* Get a list of databases */
 5837                          1187              40 :     dblist = get_database_list();
 5861 alvherre                 1188 ECB             : 
                               1189                 :     /*
                               1190                 :      * Determine the oldest datfrozenxid/relfrozenxid that we will allow to
 5624 bruce                    1191                 :      * pass without forcing a vacuum.  (This limit can be tightened for
                               1192                 :      * particular tables, but not loosened.)
                               1193                 :      */
  783 tmunro                   1194 CBC          40 :     recentXid = ReadNextTransactionId();
 5861 alvherre                 1195 GIC          40 :     xidForceLimit = recentXid - autovacuum_freeze_max_age;
                               1196                 :     /* ensure it's a "normal" XID, else TransactionIdPrecedes misbehaves */
                               1197                 :     /* this can cause the limit to go backwards by 3, but that's OK */
                               1198              40 :     if (xidForceLimit < FirstNormalTransactionId)
 5861 alvherre                 1199 UIC           0 :         xidForceLimit -= FirstNormalTransactionId;
                               1200                 : 
 3728 alvherre                 1201 ECB             :     /* Also determine the oldest datminmxid we will consider. */
 3728 alvherre                 1202 CBC          40 :     recentMulti = ReadNextMultiXactId();
 2893 rhaas                    1203 GIC          40 :     multiForceLimit = recentMulti - MultiXactMemberFreezeThreshold();
 3728 alvherre                 1204              40 :     if (multiForceLimit < FirstMultiXactId)
 3728 alvherre                 1205 LBC           0 :         multiForceLimit -= FirstMultiXactId;
 3728 alvherre                 1206 EUB             : 
                               1207                 :     /*
                               1208                 :      * Choose a database to connect to.  We pick the database that was least
 5861 alvherre                 1209 ECB             :      * recently auto-vacuumed, or one that needs vacuuming to prevent Xid
 3728                          1210                 :      * wraparound-related data loss.  If any db at risk of Xid wraparound is
 5861                          1211                 :      * found, we pick the one with oldest datfrozenxid, independently of
 3728 alvherre                 1212 EUB             :      * autovacuum times; similarly we pick the one with the oldest datminmxid
                               1213                 :      * if any is in MultiXactId wraparound.  Note that those in Xid wraparound
                               1214                 :      * danger are given more priority than those in multi wraparound danger.
                               1215                 :      *
                               1216                 :      * Note that a database with no stats entry is not considered, except for
                               1217                 :      * Xid wraparound purposes.  The theory is that if no one has ever
                               1218                 :      * connected to it since the stats were last initialized, it doesn't need
                               1219                 :      * vacuuming.
                               1220                 :      *
                               1221                 :      * XXX This could be improved if we had more info about whether it needs
                               1222                 :      * vacuuming before connecting to it.  Perhaps look through the pgstats
                               1223                 :      * data for the database's tables?  One idea is to keep track of the
                               1224                 :      * number of new and dead tuples per database in pgstats.  However it
                               1225                 :      * isn't clear how to construct a metric that measures that and not cause
                               1226                 :      * starvation for less busy databases.
                               1227                 :      */
 5837 alvherre                 1228 GIC          40 :     avdb = NULL;
 5861                          1229              40 :     for_xid_wrap = false;
 3728                          1230              40 :     for_multi_wrap = false;
 5837                          1231              40 :     current_time = GetCurrentTimestamp();
 5861                          1232             202 :     foreach(cell, dblist)
                               1233                 :     {
 5837                          1234             162 :         avw_dbase  *tmp = lfirst(cell);
 3602 bruce                    1235 ECB             :         dlist_iter  iter;
 5861 alvherre                 1236                 : 
                               1237                 :         /* Check to see if this one is at risk of wraparound */
 5837 alvherre                 1238 CBC         162 :         if (TransactionIdPrecedes(tmp->adw_frozenxid, xidForceLimit))
 5861 alvherre                 1239 ECB             :         {
 5837 alvherre                 1240 UIC           0 :             if (avdb == NULL ||
 3728 alvherre                 1241 LBC           0 :                 TransactionIdPrecedes(tmp->adw_frozenxid,
                               1242                 :                                       avdb->adw_frozenxid))
 5837 alvherre                 1243 UIC           0 :                 avdb = tmp;
 5861                          1244               0 :             for_xid_wrap = true;
 5861 alvherre                 1245 CBC         132 :             continue;
                               1246                 :         }
 5861 alvherre                 1247 GBC         162 :         else if (for_xid_wrap)
 5861 alvherre                 1248 UBC           0 :             continue;           /* ignore not-at-risk DBs */
 3492 alvherre                 1249 GIC         162 :         else if (MultiXactIdPrecedes(tmp->adw_minmulti, multiForceLimit))
 3728 alvherre                 1250 EUB             :         {
 3728 alvherre                 1251 UBC           0 :             if (avdb == NULL ||
 3492 alvherre                 1252 LBC           0 :                 MultiXactIdPrecedes(tmp->adw_minmulti, avdb->adw_minmulti))
 3728 alvherre                 1253 UIC           0 :                 avdb = tmp;
 3728 alvherre                 1254 LBC           0 :             for_multi_wrap = true;
 3728 alvherre                 1255 UBC           0 :             continue;
 3728 alvherre                 1256 ECB             :         }
 3728 alvherre                 1257 GIC         162 :         else if (for_multi_wrap)
 3728 alvherre                 1258 UBC           0 :             continue;           /* ignore not-at-risk DBs */
 5861 alvherre                 1259 EUB             : 
 5676                          1260                 :         /* Find pgstat entry if any */
 5676 alvherre                 1261 GBC         162 :         tmp->adw_entry = pgstat_fetch_stat_dbentry(tmp->adw_datid);
 5676 alvherre                 1262 EUB             : 
                               1263                 :         /*
 5676 alvherre                 1264 ECB             :          * Skip a database with no pgstat entry; it means it hasn't seen any
 5676 alvherre                 1265 EUB             :          * activity.
                               1266                 :          */
 5837 alvherre                 1267 GIC         162 :         if (!tmp->adw_entry)
 5837 alvherre                 1268 CBC         106 :             continue;
                               1269                 : 
                               1270                 :         /*
                               1271                 :          * Also, skip a database that appears on the database list as having
                               1272                 :          * been processed recently (less than autovacuum_naptime seconds ago).
                               1273                 :          * We do this so that we don't select a database which we just
 5837 alvherre                 1274 ECB             :          * selected, but that pgstat hasn't gotten around to updating the last
                               1275                 :          * autovacuum time yet.
                               1276                 :          */
 5837 alvherre                 1277 GIC          56 :         skipit = false;
                               1278                 : 
 3827                          1279             124 :         dlist_reverse_foreach(iter, &DatabaseList)
                               1280                 :         {
                               1281             110 :             avl_dbase  *dbp = dlist_container(avl_dbase, adl_node, iter.cur);
                               1282                 : 
 5837                          1283             110 :             if (dbp->adl_datid == tmp->adw_datid)
 5837 alvherre                 1284 ECB             :             {
                               1285                 :                 /*
 5821                          1286                 :                  * Skip this database if its next_worker value falls between
                               1287                 :                  * the current time and the current time plus naptime.
 5837                          1288                 :                  */
 5816 alvherre                 1289 GIC          42 :                 if (!TimestampDifferenceExceeds(dbp->adl_next_worker,
 5624 bruce                    1290 CBC          26 :                                                 current_time, 0) &&
 5821 alvherre                 1291 GIC          26 :                     !TimestampDifferenceExceeds(current_time,
                               1292                 :                                                 dbp->adl_next_worker,
                               1293                 :                                                 autovacuum_naptime * 1000))
 5837                          1294              26 :                     skipit = true;
                               1295                 : 
 5837 alvherre                 1296 CBC          42 :                 break;
 5837 alvherre                 1297 ECB             :             }
                               1298                 :         }
 5837 alvherre                 1299 GIC          56 :         if (skipit)
 5861                          1300              26 :             continue;
 5861 alvherre                 1301 ECB             : 
                               1302                 :         /*
 5624 bruce                    1303                 :          * Remember the db with oldest autovac time.  (If we are here, both
                               1304                 :          * tmp->entry and db->entry must be non-null.)
                               1305                 :          */
 5837 alvherre                 1306 CBC          30 :         if (avdb == NULL ||
                               1307              14 :             tmp->adw_entry->last_autovac_time < avdb->adw_entry->last_autovac_time)
 5837 alvherre                 1308 GIC          16 :             avdb = tmp;
                               1309                 :     }
                               1310                 : 
                               1311                 :     /* Found a database -- process it */
                               1312              40 :     if (avdb != NULL)
 5861 alvherre                 1313 ECB             :     {
 5837                          1314                 :         WorkerInfo  worker;
 3827                          1315                 :         dlist_node *wptr;
                               1316                 : 
 5861 alvherre                 1317 GIC          16 :         LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
                               1318                 : 
 5837 alvherre                 1319 ECB             :         /*
                               1320                 :          * Get a worker entry from the freelist.  We checked above, so there
                               1321                 :          * really should be a free slot.
                               1322                 :          */
 3827 alvherre                 1323 GIC          16 :         wptr = dlist_pop_head_node(&AutoVacuumShmem->av_freeWorkers);
 5837 alvherre                 1324 ECB             : 
 3827 alvherre                 1325 GIC          16 :         worker = dlist_container(WorkerInfoData, wi_links, wptr);
 5837                          1326              16 :         worker->wi_dboid = avdb->adw_datid;
 5646                          1327              16 :         worker->wi_proc = NULL;
 5837                          1328              16 :         worker->wi_launchtime = GetCurrentTimestamp();
                               1329                 : 
 5271 tgl                      1330 CBC          16 :         AutoVacuumShmem->av_startingWorker = worker;
                               1331                 : 
 5861 alvherre                 1332              16 :         LWLockRelease(AutovacuumLock);
 5861 alvherre                 1333 ECB             : 
 5861 alvherre                 1334 CBC          16 :         SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
 5837 alvherre                 1335 ECB             : 
 5688 alvherre                 1336 GIC          16 :         retval = avdb->adw_datid;
 5837 alvherre                 1337 ECB             :     }
 5837 alvherre                 1338 GIC          24 :     else if (skipit)
 5837 alvherre                 1339 ECB             :     {
                               1340                 :         /*
                               1341                 :          * If we skipped all databases on the list, rebuild it, because it
                               1342                 :          * probably contains a dropped database.
                               1343                 :          */
 5837 alvherre                 1344 UIC           0 :         rebuild_database_list(InvalidOid);
 5837 alvherre                 1345 ECB             :     }
                               1346                 : 
 5688 alvherre                 1347 GIC          40 :     MemoryContextSwitchTo(oldcxt);
                               1348              40 :     MemoryContextDelete(tmpcxt);
                               1349                 : 
                               1350              40 :     return retval;
 5837 alvherre                 1351 EUB             : }
                               1352                 : 
                               1353                 : /*
 5837 alvherre                 1354 ECB             :  * launch_worker
                               1355                 :  *
                               1356                 :  * Wrapper for starting a worker from the launcher.  Besides actually starting
                               1357                 :  * it, update the database list to reflect the next time that another one will
                               1358                 :  * need to be started on the selected database.  The actual database choice is
                               1359                 :  * left to do_start_worker.
                               1360                 :  *
                               1361                 :  * This routine is also expected to insert an entry into the database list if
                               1362                 :  * the selected database was previously absent from the list.
                               1363                 :  */
                               1364                 : static void
 5837 alvherre                 1365 GIC          40 : launch_worker(TimestampTz now)
                               1366                 : {
                               1367                 :     Oid         dbid;
                               1368                 :     dlist_iter  iter;
                               1369                 : 
                               1370              40 :     dbid = do_start_worker();
                               1371              40 :     if (OidIsValid(dbid))
 5837 alvherre                 1372 ECB             :     {
 3602 bruce                    1373 GIC          16 :         bool        found = false;
                               1374                 : 
                               1375                 :         /*
                               1376                 :          * Walk the database list and update the corresponding entry.  If the
 5837 alvherre                 1377 ECB             :          * database is not on the list, we'll recreate the list.
                               1378                 :          */
 3827 alvherre                 1379 GIC          48 :         dlist_foreach(iter, &DatabaseList)
 5837 alvherre                 1380 ECB             :         {
 3827 alvherre                 1381 GIC          42 :             avl_dbase  *avdb = dlist_container(avl_dbase, adl_node, iter.cur);
                               1382                 : 
 5837                          1383              42 :             if (avdb->adl_datid == dbid)
                               1384                 :             {
 3827                          1385              10 :                 found = true;
 3827 alvherre                 1386 ECB             : 
                               1387                 :                 /*
 5837                          1388                 :                  * add autovacuum_naptime seconds to the current time, and use
                               1389                 :                  * that as the new "next_worker" field for this database.
                               1390                 :                  */
 5837 alvherre                 1391 GIC          10 :                 avdb->adl_next_worker =
 5837 alvherre                 1392 CBC          10 :                     TimestampTzPlusMilliseconds(now, autovacuum_naptime * 1000);
                               1393                 : 
 3827 alvherre                 1394 GIC          10 :                 dlist_move_head(&DatabaseList, iter.cur);
 5837                          1395              10 :                 break;
                               1396                 :             }
                               1397                 :         }
 5837 alvherre                 1398 ECB             : 
                               1399                 :         /*
                               1400                 :          * If the database was not present in the database list, we rebuild
 5624 bruce                    1401                 :          * the list.  It's possible that the database does not get into the
                               1402                 :          * list anyway, for example if it's a database that doesn't have a
                               1403                 :          * pgstat entry, but this is not a problem because we don't want to
                               1404                 :          * schedule workers regularly into those in any case.
                               1405                 :          */
 3827 alvherre                 1406 GIC          16 :         if (!found)
 5837                          1407               6 :             rebuild_database_list(dbid);
                               1408                 :     }
 5861                          1409              40 : }
                               1410                 : 
                               1411                 : /*
                               1412                 :  * Called from postmaster to signal a failure to fork a process to become
 3260 bruce                    1413 ECB             :  * worker.  The postmaster should kill(SIGUSR2) the launcher shortly
 5767 alvherre                 1414                 :  * after calling this function.
                               1415                 :  */
                               1416                 : void
 5767 alvherre                 1417 UIC           0 : AutoVacWorkerFailed(void)
                               1418                 : {
                               1419               0 :     AutoVacuumShmem->av_signal[AutoVacForkFailed] = true;
                               1420               0 : }
                               1421                 : 
                               1422                 : /* SIGUSR2: a worker is up and running, or just finished, or failed to fork */
                               1423                 : static void
 4969 tgl                      1424 GBC          32 : avl_sigusr2_handler(SIGNAL_ARGS)
                               1425                 : {
 4260                          1426              32 :     int         save_errno = errno;
 4260 tgl                      1427 EUB             : 
 4969 tgl                      1428 GIC          32 :     got_SIGUSR2 = true;
 3007 andres                   1429              32 :     SetLatch(MyLatch);
                               1430                 : 
 4260 tgl                      1431 CBC          32 :     errno = save_errno;
 5837 alvherre                 1432 GIC          32 : }
 5837 alvherre                 1433 ECB             : 
                               1434                 : 
 5897                          1435                 : /********************************************************************
 5624 bruce                    1436                 :  *                    AUTOVACUUM WORKER CODE
                               1437                 :  ********************************************************************/
 5897 alvherre                 1438                 : 
 6478 tgl                      1439                 : #ifdef EXEC_BACKEND
                               1440                 : /*
                               1441                 :  * forkexec routines for the autovacuum worker.
                               1442                 :  *
                               1443                 :  * Format up the arglist, then fork and exec.
                               1444                 :  */
                               1445                 : static pid_t
                               1446                 : avworker_forkexec(void)
                               1447                 : {
                               1448                 :     char       *av[10];
                               1449                 :     int         ac = 0;
                               1450                 : 
                               1451                 :     av[ac++] = "postgres";
                               1452                 :     av[ac++] = "--forkavworker";
                               1453                 :     av[ac++] = NULL;            /* filled in by postmaster_forkexec */
                               1454                 :     av[ac] = NULL;
                               1455                 : 
                               1456                 :     Assert(ac < lengthof(av));
                               1457                 : 
                               1458                 :     return postmaster_forkexec(ac, av);
                               1459                 : }
                               1460                 : 
                               1461                 : /*
                               1462                 :  * We need this set from the outside, before InitProcess is called
                               1463                 :  */
                               1464                 : void
                               1465                 : AutovacuumWorkerIAm(void)
                               1466                 : {
                               1467                 :     am_autovacuum_worker = true;
                               1468                 : }
                               1469                 : #endif
                               1470                 : 
                               1471                 : /*
                               1472                 :  * Main entry point for autovacuum worker process.
                               1473                 :  *
                               1474                 :  * This code is heavily based on pgarch.c, q.v.
                               1475                 :  */
                               1476                 : int
 5897 alvherre                 1477 GIC          16 : StartAutoVacWorker(void)
                               1478                 : {
                               1479                 :     pid_t       worker_pid;
                               1480                 : 
                               1481                 : #ifdef EXEC_BACKEND
                               1482                 :     switch ((worker_pid = avworker_forkexec()))
                               1483                 : #else
 5897 alvherre                 1484 CBC          16 :     switch ((worker_pid = fork_process()))
                               1485                 : #endif
                               1486                 :     {
 5897 alvherre                 1487 UIC           0 :         case -1:
                               1488               0 :             ereport(LOG,
                               1489                 :                     (errmsg("could not fork autovacuum worker process: %m")));
                               1490               0 :             return 0;
 5897 alvherre                 1491 ECB             : 
                               1492                 : #ifndef EXEC_BACKEND
 5897 alvherre                 1493 GIC          16 :         case 0:
 5897 alvherre                 1494 EUB             :             /* in postmaster child ... */
 3008 andres                   1495 GBC          16 :             InitPostmasterChild();
                               1496                 : 
 5897 alvherre                 1497 EUB             :             /* Close the postmaster's sockets */
 5897 alvherre                 1498 GIC          16 :             ClosePostmasterPorts(false);
                               1499                 : 
 5897 alvherre                 1500 CBC          16 :             AutoVacWorkerMain(0, NULL);
                               1501                 :             break;
 5897 alvherre                 1502 ECB             : #endif
 5897 alvherre                 1503 GIC          16 :         default:
                               1504              16 :             return (int) worker_pid;
 5897 alvherre                 1505 ECB             :     }
                               1506                 : 
                               1507                 :     /* shouldn't get here */
                               1508                 :     return 0;
                               1509                 : }
 6478 tgl                      1510                 : 
                               1511                 : /*
                               1512                 :  * AutoVacWorkerMain
                               1513                 :  */
                               1514                 : NON_EXEC_STATIC void
 5897 alvherre                 1515 GIC          16 : AutoVacWorkerMain(int argc, char *argv[])
                               1516                 : {
                               1517                 :     sigjmp_buf  local_sigjmp_buf;
                               1518                 :     Oid         dbid;
                               1519                 : 
                               1520              16 :     am_autovacuum_worker = true;
                               1521                 : 
 1124 peter                    1522 CBC          16 :     MyBackendType = B_AUTOVAC_WORKER;
 1124 peter                    1523 GIC          16 :     init_ps_display(NULL);
                               1524                 : 
 6450 tgl                      1525              16 :     SetProcessingMode(InitProcessing);
                               1526                 : 
 6478 tgl                      1527 ECB             :     /*
                               1528                 :      * Set up signal handlers.  We operate on databases much like a regular
 6385 bruce                    1529                 :      * backend, so we use the same signal handling.  See equivalent code in
                               1530                 :      * tcop/postgres.c.
                               1531                 :      */
 1209 rhaas                    1532 CBC          16 :     pqsignal(SIGHUP, SignalHandlerForConfigReload);
                               1533                 : 
                               1534                 :     /*
                               1535                 :      * SIGINT is used to signal canceling the current table's vacuum; SIGTERM
                               1536                 :      * means abort and exit cleanly, and SIGQUIT means abandon ship.
                               1537                 :      */
 6478 tgl                      1538 GIC          16 :     pqsignal(SIGINT, StatementCancelHandler);
 6478 tgl                      1539 CBC          16 :     pqsignal(SIGTERM, die);
                               1540                 :     /* SIGQUIT handler was already set up by InitPostmasterChild */
                               1541                 : 
 3919 alvherre                 1542 GIC          16 :     InitializeTimeouts();       /* establishes SIGALRM handler */
                               1543                 : 
 6478 tgl                      1544              16 :     pqsignal(SIGPIPE, SIG_IGN);
 5000 tgl                      1545 CBC          16 :     pqsignal(SIGUSR1, procsignal_sigusr1_handler);
 6478                          1546              16 :     pqsignal(SIGUSR2, SIG_IGN);
 6450 tgl                      1547 GIC          16 :     pqsignal(SIGFPE, FloatExceptionHandler);
 6478                          1548              16 :     pqsignal(SIGCHLD, SIG_DFL);
 6478 tgl                      1549 ECB             : 
                               1550                 :     /*
 6031 bruce                    1551                 :      * Create a per-backend PGPROC struct in shared memory, except in the
                               1552                 :      * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
                               1553                 :      * this before we can use LWLocks (and in the EXEC_BACKEND case we already
                               1554                 :      * had to do some stuff with LWLocks).
 6304 tgl                      1555                 :      */
                               1556                 : #ifndef EXEC_BACKEND
 6304 tgl                      1557 GIC          16 :     InitProcess();
                               1558                 : #endif
                               1559                 : 
                               1560                 :     /* Early initialization */
  612 andres                   1561              16 :     BaseInit();
                               1562                 : 
                               1563                 :     /*
 6478 tgl                      1564 ECB             :      * If an exception is encountered, processing resumes here.
                               1565                 :      *
                               1566                 :      * Unlike most auxiliary processes, we don't attempt to continue
                               1567                 :      * processing after an error; we just clean up and exit.  The autovac
  940                          1568                 :      * launcher is responsible for spawning another worker later.
                               1569                 :      *
                               1570                 :      * Note that we use sigsetjmp(..., 1), so that the prevailing signal mask
                               1571                 :      * (to wit, BlockSig) will be restored when longjmp'ing to here.  Thus,
                               1572                 :      * signals other than SIGQUIT will be blocked until we exit.  It might
                               1573                 :      * seem that this policy makes the HOLD_INTERRUPTS() call redundant, but
                               1574                 :      * it is not since InterruptPending might be set already.
                               1575                 :      */
 6478 tgl                      1576 GIC          16 :     if (sigsetjmp(local_sigjmp_buf, 1) != 0)
                               1577                 :     {
                               1578                 :         /* since not using PG_TRY, must reset error stack by hand */
 1264 michael                  1579 UIC           0 :         error_context_stack = NULL;
                               1580                 : 
                               1581                 :         /* Prevents interrupts while cleaning up */
 6478 tgl                      1582               0 :         HOLD_INTERRUPTS();
 6478 tgl                      1583 ECB             : 
                               1584                 :         /* Report the error to the server log */
 6478 tgl                      1585 UIC           0 :         EmitErrorReport();
 6478 tgl                      1586 EUB             : 
                               1587                 :         /*
                               1588                 :          * We can now go away.  Note that because we called InitProcess, a
 5927 alvherre                 1589                 :          * callback was registered to do ProcKill, which will clean up
                               1590                 :          * necessary state.
                               1591                 :          */
 6478 tgl                      1592 UBC           0 :         proc_exit(0);
                               1593                 :     }
                               1594                 : 
                               1595                 :     /* We can now handle ereport(ERROR) */
 6478 tgl                      1596 GIC          16 :     PG_exception_stack = &local_sigjmp_buf;
                               1597                 : 
   65 tmunro                   1598 GNC          16 :     sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
 6478 tgl                      1599 EUB             : 
                               1600                 :     /*
                               1601                 :      * Set always-secure search path, so malicious users can't redirect user
                               1602                 :      * code (e.g. pg_index.indexprs).  (That code runs in a
 1868 noah                     1603 ECB             :      * SECURITY_RESTRICTED_OPERATION sandbox, so malicious users could not
                               1604                 :      * take control of the entire autovacuum worker in any case.)
                               1605                 :      */
 1868 noah                     1606 GIC          16 :     SetConfigOption("search_path", "", PGC_SUSET, PGC_S_OVERRIDE);
                               1607                 : 
                               1608                 :     /*
                               1609                 :      * Force zero_damaged_pages OFF in the autovac process, even if it is set
                               1610                 :      * in postgresql.conf.  We don't really want such a dangerous option being
                               1611                 :      * applied non-interactively.
                               1612                 :      */
 6242 tgl                      1613 CBC          16 :     SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
                               1614                 : 
                               1615                 :     /*
                               1616                 :      * Force settable timeouts off to avoid letting these settings prevent
                               1617                 :      * regular maintenance from being executed.
                               1618                 :      */
 5837 alvherre                 1619 GIC          16 :     SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
 3676 tgl                      1620 CBC          16 :     SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
 2489 tgl                      1621 GIC          16 :     SetConfigOption("idle_in_transaction_session_timeout", "0",
                               1622                 :                     PGC_SUSET, PGC_S_OVERRIDE);
                               1623                 : 
                               1624                 :     /*
                               1625                 :      * Force default_transaction_isolation to READ COMMITTED.  We don't want
 3955 bruce                    1626 ECB             :      * to pay the overhead of serializable mode, nor add any risk of causing
                               1627                 :      * deadlocks or delaying other transactions.
 4149 tgl                      1628                 :      */
 4149 tgl                      1629 GIC          16 :     SetConfigOption("default_transaction_isolation", "read committed",
                               1630                 :                     PGC_SUSET, PGC_S_OVERRIDE);
                               1631                 : 
                               1632                 :     /*
                               1633                 :      * Force synchronous replication off to allow regular maintenance even if
                               1634                 :      * we are waiting for standbys to connect. This is important to ensure we
                               1635                 :      * aren't blocked from performing anti-wraparound tasks.
 4417 simon                    1636 ECB             :      */
 4388 simon                    1637 GIC          16 :     if (synchronous_commit > SYNCHRONOUS_COMMIT_LOCAL_FLUSH)
 4149 tgl                      1638              16 :         SetConfigOption("synchronous_commit", "local",
                               1639                 :                         PGC_SUSET, PGC_S_OVERRIDE);
                               1640                 : 
                               1641                 :     /*
                               1642                 :      * Even when system is configured to use a different fetch consistency,
                               1643                 :      * for autovac we always want fresh stats.
  368 andres                   1644 ECB             :      */
  368 andres                   1645 CBC          16 :     SetConfigOption("stats_fetch_consistency", "none", PGC_SUSET, PGC_S_OVERRIDE);
                               1646                 : 
                               1647                 :     /*
                               1648                 :      * Get the info about the database we're going to work on.
                               1649                 :      */
 5837 alvherre                 1650 GIC          16 :     LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
                               1651                 : 
 5837 alvherre                 1652 ECB             :     /*
                               1653                 :      * beware of startingWorker being INVALID; this should normally not
                               1654                 :      * happen, but if a worker fails after forking and before this, the
                               1655                 :      * launcher might have decided to remove it from the queue and start
                               1656                 :      * again.
                               1657                 :      */
 5271 tgl                      1658 GIC          16 :     if (AutoVacuumShmem->av_startingWorker != NULL)
                               1659                 :     {
                               1660              16 :         MyWorkerInfo = AutoVacuumShmem->av_startingWorker;
 5821 alvherre                 1661              16 :         dbid = MyWorkerInfo->wi_dboid;
 5646                          1662              16 :         MyWorkerInfo->wi_proc = MyProc;
                               1663                 : 
                               1664                 :         /* insert into the running list */
 3827 alvherre                 1665 CBC          16 :         dlist_push_head(&AutoVacuumShmem->av_runningWorkers,
 3827 alvherre                 1666 GIC          16 :                         &MyWorkerInfo->wi_links);
 5762 alvherre                 1667 ECB             : 
 5821                          1668                 :         /*
 5819 tgl                      1669                 :          * remove from the "starting" pointer, so that the launcher can start
                               1670                 :          * a new worker if required
                               1671                 :          */
 5271 tgl                      1672 CBC          16 :         AutoVacuumShmem->av_startingWorker = NULL;
 5821 alvherre                 1673              16 :         LWLockRelease(AutovacuumLock);
                               1674                 : 
 5821 alvherre                 1675 GIC          16 :         on_shmem_exit(FreeWorkerInfo, 0);
                               1676                 : 
                               1677                 :         /* wake up the launcher */
                               1678              16 :         if (AutoVacuumShmem->av_launcherpid != 0)
 4969 tgl                      1679 CBC          16 :             kill(AutoVacuumShmem->av_launcherpid, SIGUSR2);
 5821 alvherre                 1680 ECB             :     }
                               1681                 :     else
 5819 tgl                      1682                 :     {
                               1683                 :         /* no worker entry for me, go away */
 5767 alvherre                 1684 UIC           0 :         elog(WARNING, "autovacuum worker started without a worker entry");
 5819 tgl                      1685 LBC           0 :         dbid = InvalidOid;
 5821 alvherre                 1686               0 :         LWLockRelease(AutovacuumLock);
                               1687                 :     }
                               1688                 : 
 5897 alvherre                 1689 GIC          16 :     if (OidIsValid(dbid))
                               1690                 :     {
 4988 tgl                      1691 EUB             :         char        dbname[NAMEDATALEN];
 5897 alvherre                 1692                 : 
 6446 tgl                      1693                 :         /*
                               1694                 :          * Report autovac startup to the cumulative stats system.  We
                               1695                 :          * deliberately do this before InitPostgres, so that the
  332 tgl                      1696 ECB             :          * last_autovac_time will get updated even if the connection attempt
                               1697                 :          * fails.  This is to prevent autovac from getting "stuck" repeatedly
                               1698                 :          * selecting an unopenable database, rather than making any progress
                               1699                 :          * on stuff it can connect to.
                               1700                 :          */
 5897 alvherre                 1701 GIC          16 :         pgstat_report_autovac(dbid);
                               1702                 : 
                               1703                 :         /*
                               1704                 :          * Connect to the selected database, specifying no particular user
                               1705                 :          *
                               1706                 :          * Note: if we have selected a just-deleted database (due to using
                               1707                 :          * stale stats info), we'll fail and exit here.
 6478 tgl                      1708 ECB             :          */
  258 tgl                      1709 GIC          16 :         InitPostgres(NULL, dbid, NULL, InvalidOid, false, false,
                               1710                 :                      dbname);
 6478                          1711              16 :         SetProcessingMode(NormalProcessing);
 1124 peter                    1712              16 :         set_ps_display(dbname);
 6191 bruce                    1713              16 :         ereport(DEBUG1,
                               1714                 :                 (errmsg_internal("autovacuum: processing database \"%s\"", dbname)));
                               1715                 : 
 5646 alvherre                 1716 CBC          16 :         if (PostAuthDelay)
 5646 alvherre                 1717 UIC           0 :             pg_usleep(PostAuthDelay * 1000000L);
 5646 alvherre                 1718 ECB             : 
 5897                          1719                 :         /* And do an appropriate amount of work */
  783 tmunro                   1720 CBC          16 :         recentXid = ReadNextTransactionId();
 3728 alvherre                 1721 GIC          16 :         recentMulti = ReadNextMultiXactId();
 5856                          1722              16 :         do_autovacuum();
 6478 tgl                      1723 ECB             :     }
 6478 tgl                      1724 EUB             : 
                               1725                 :     /*
                               1726                 :      * The launcher will be notified of my death in ProcKill, *if* we managed
 5821 alvherre                 1727 ECB             :      * to get a worker slot at all
 5897                          1728                 :      */
                               1729                 : 
                               1730                 :     /* All done, go away */
 6478 tgl                      1731 GIC          16 :     proc_exit(0);
                               1732                 : }
                               1733                 : 
                               1734                 : /*
                               1735                 :  * Return a WorkerInfo to the free list
                               1736                 :  */
                               1737                 : static void
 5837 alvherre                 1738 CBC          16 : FreeWorkerInfo(int code, Datum arg)
                               1739                 : {
 5837 alvherre                 1740 GIC          16 :     if (MyWorkerInfo != NULL)
                               1741                 :     {
                               1742              16 :         LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
                               1743                 : 
                               1744                 :         /*
 5767 alvherre                 1745 ECB             :          * Wake the launcher up so that he can launch a new worker immediately
                               1746                 :          * if required.  We only save the launcher's PID in local memory here;
 3260 bruce                    1747                 :          * the actual signal will be sent when the PGPROC is recycled.  Note
                               1748                 :          * that we always do this, so that the launcher can rebalance the cost
 5767 alvherre                 1749                 :          * limit setting of the remaining workers.
                               1750                 :          *
                               1751                 :          * We somewhat ignore the risk that the launcher changes its PID
                               1752                 :          * between us reading it and the actual kill; we expect ProcKill to be
                               1753                 :          * called shortly after us, and we assume that PIDs are not reused too
                               1754                 :          * quickly after a process exits.
                               1755                 :          */
 5767 alvherre                 1756 GIC          16 :         AutovacuumLauncherPid = AutoVacuumShmem->av_launcherpid;
                               1757                 : 
 3825 tgl                      1758              16 :         dlist_delete(&MyWorkerInfo->wi_links);
 5837 alvherre                 1759              16 :         MyWorkerInfo->wi_dboid = InvalidOid;
                               1760              16 :         MyWorkerInfo->wi_tableoid = InvalidOid;
 2525                          1761              16 :         MyWorkerInfo->wi_sharedrel = false;
 5646                          1762              16 :         MyWorkerInfo->wi_proc = NULL;
 5837 alvherre                 1763 CBC          16 :         MyWorkerInfo->wi_launchtime = 0;
    2 dgustafsson              1764 GNC          16 :         pg_atomic_clear_flag(&MyWorkerInfo->wi_dobalance);
 3825 tgl                      1765 CBC          16 :         dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
                               1766              16 :                         &MyWorkerInfo->wi_links);
 5837 alvherre                 1767 ECB             :         /* not mine anymore */
 5837 alvherre                 1768 CBC          16 :         MyWorkerInfo = NULL;
 5837 alvherre                 1769 ECB             : 
                               1770                 :         /*
                               1771                 :          * now that we're inactive, cause a rebalancing of the surviving
                               1772                 :          * workers
                               1773                 :          */
 5767 alvherre                 1774 GIC          16 :         AutoVacuumShmem->av_signal[AutoVacRebalance] = true;
 5837                          1775              16 :         LWLockRelease(AutovacuumLock);
                               1776                 :     }
                               1777              16 : }
 5837 alvherre                 1778 ECB             : 
                               1779                 : /*
                               1780                 :  * Update vacuum cost-based delay-related parameters for autovacuum workers and
                               1781                 :  * backends executing VACUUM or ANALYZE using the value of relevant GUCs and
                               1782                 :  * global state. This must be called during setup for vacuum and after every
                               1783                 :  * config reload to ensure up-to-date values.
                               1784                 :  */
                               1785                 : void
    2 dgustafsson              1786 GNC        5239 : VacuumUpdateCosts(void)
                               1787                 : {
                               1788            5239 :     double      original_cost_delay = vacuum_cost_delay;
                               1789            5239 :     int         original_cost_limit = vacuum_cost_limit;
                               1790                 : 
 5837 alvherre                 1791 GIC        5239 :     if (MyWorkerInfo)
                               1792                 :     {
    2 dgustafsson              1793 GNC         316 :         if (av_storage_param_cost_delay >= 0)
    2 dgustafsson              1794 UNC           0 :             vacuum_cost_delay = av_storage_param_cost_delay;
    2 dgustafsson              1795 GNC         316 :         else if (autovacuum_vac_cost_delay >= 0)
                               1796             316 :             vacuum_cost_delay = autovacuum_vac_cost_delay;
                               1797                 :         else
                               1798                 :             /* fall back to VacuumCostDelay */
    2 dgustafsson              1799 UNC           0 :             vacuum_cost_delay = VacuumCostDelay;
                               1800                 : 
    2 dgustafsson              1801 GNC         316 :         AutoVacuumUpdateCostLimit();
                               1802                 :     }
                               1803                 :     else
                               1804                 :     {
                               1805                 :         /* Must be explicit VACUUM or ANALYZE */
                               1806            4923 :         vacuum_cost_delay = VacuumCostDelay;
                               1807            4923 :         vacuum_cost_limit = VacuumCostLimit;
                               1808                 :     }
                               1809                 : 
                               1810                 :     /*
                               1811                 :      * If configuration changes are allowed to impact VacuumCostActive, make
                               1812                 :      * sure it is updated.
                               1813                 :      */
                               1814            5239 :     if (VacuumFailsafeActive)
    2 dgustafsson              1815 UNC           0 :         Assert(!VacuumCostActive);
    2 dgustafsson              1816 GNC        5239 :     else if (vacuum_cost_delay > 0)
                               1817             316 :         VacuumCostActive = true;
                               1818                 :     else
                               1819                 :     {
                               1820            4923 :         VacuumCostActive = false;
                               1821            4923 :         VacuumCostBalance = 0;
                               1822                 :     }
                               1823                 : 
                               1824            5239 :     if (MyWorkerInfo)
                               1825                 :     {
                               1826                 :         Oid         dboid,
                               1827                 :                     tableoid;
                               1828                 : 
                               1829                 :         /* Only log updates to cost-related variables */
                               1830             316 :         if (vacuum_cost_delay == original_cost_delay &&
                               1831             303 :             vacuum_cost_limit == original_cost_limit)
                               1832             303 :             return;
                               1833                 : 
                               1834              13 :         Assert(!LWLockHeldByMe(AutovacuumLock));
                               1835                 : 
                               1836              13 :         LWLockAcquire(AutovacuumLock, LW_SHARED);
                               1837              13 :         dboid = MyWorkerInfo->wi_dboid;
                               1838              13 :         tableoid = MyWorkerInfo->wi_tableoid;
                               1839              13 :         LWLockRelease(AutovacuumLock);
                               1840                 : 
                               1841              13 :         elog(DEBUG2,
                               1842                 :              "Autovacuum VacuumUpdateCosts(db=%u, rel=%u, dobalance=%s, cost_limit=%d, cost_delay=%g active=%s failsafe=%s)",
                               1843                 :              dboid, tableoid, pg_atomic_unlocked_test_flag(&MyWorkerInfo->wi_dobalance) ? "no" : "yes",
                               1844                 :              vacuum_cost_limit, vacuum_cost_delay,
                               1845                 :              vacuum_cost_delay > 0 ? "yes" : "no",
                               1846                 :              VacuumFailsafeActive ? "yes" : "no");
                               1847                 : 
    2 dgustafsson              1848 ECB             :     }
                               1849                 : }
 5837 alvherre                 1850                 : 
                               1851                 : /*
                               1852                 :  * Update vacuum_cost_limit with the correct value for an autovacuum worker,
                               1853                 :  * given the value of other relevant cost limit parameters and the number of
                               1854                 :  * workers across which the limit must be balanced. Autovacuum workers must
                               1855                 :  * call this regularly in case av_nworkersForBalance has been updated by
                               1856                 :  * another worker or by the autovacuum launcher. They must also call it after a
                               1857                 :  * config reload.
 5837 alvherre                 1858 EUB             :  */
                               1859                 : void
    2 dgustafsson              1860 GNC         575 : AutoVacuumUpdateCostLimit(void)
                               1861                 : {
                               1862             575 :     if (!MyWorkerInfo)
    2 dgustafsson              1863 UNC           0 :         return;
                               1864                 : 
                               1865                 :     /*
                               1866                 :      * note: in cost_limit, zero also means use value from elsewhere, because
                               1867                 :      * zero is not a valid value.
                               1868                 :      */
                               1869                 : 
    2 dgustafsson              1870 GNC         575 :     if (av_storage_param_cost_limit > 0)
    2 dgustafsson              1871 UNC           0 :         vacuum_cost_limit = av_storage_param_cost_limit;
                               1872                 :     else
                               1873                 :     {
                               1874                 :         int         nworkers_for_balance;
                               1875                 : 
    2 dgustafsson              1876 GNC         575 :         if (autovacuum_vac_cost_limit > 0)
    2 dgustafsson              1877 UNC           0 :             vacuum_cost_limit = autovacuum_vac_cost_limit;
                               1878                 :         else
    2 dgustafsson              1879 GNC         575 :             vacuum_cost_limit = VacuumCostLimit;
                               1880                 : 
                               1881                 :         /* Only balance limit if no cost-related storage parameters specified */
                               1882             575 :         if (pg_atomic_unlocked_test_flag(&MyWorkerInfo->wi_dobalance))
    2 dgustafsson              1883 UNC           0 :             return;
                               1884                 : 
    2 dgustafsson              1885 GNC         575 :         Assert(vacuum_cost_limit > 0);
                               1886                 : 
                               1887             575 :         nworkers_for_balance = pg_atomic_read_u32(&AutoVacuumShmem->av_nworkersForBalance);
                               1888                 : 
                               1889                 :         /* There is at least 1 autovac worker (this worker) */
                               1890             575 :         if (nworkers_for_balance <= 0)
    2 dgustafsson              1891 UNC           0 :             elog(ERROR, "nworkers_for_balance must be > 0");
                               1892                 : 
    2 dgustafsson              1893 GNC         575 :         vacuum_cost_limit = Max(vacuum_cost_limit / nworkers_for_balance, 1);
                               1894                 :     }
                               1895                 : }
                               1896                 : 
                               1897                 : /*
                               1898                 :  * autovac_recalculate_workers_for_balance
                               1899                 :  *      Recalculate the number of workers to consider, given cost-related
                               1900                 :  *      storage parameters and the current number of active workers.
                               1901                 :  *
                               1902                 :  * Caller must hold the AutovacuumLock in at least shared mode to access
                               1903                 :  * worker->wi_proc.
                               1904                 :  */
                               1905                 : static void
                               1906             174 : autovac_recalculate_workers_for_balance(void)
                               1907                 : {
                               1908                 :     dlist_iter  iter;
                               1909                 :     int         orig_nworkers_for_balance;
                               1910             174 :     int         nworkers_for_balance = 0;
                               1911                 : 
                               1912             174 :     Assert(LWLockHeldByMe(AutovacuumLock));
                               1913                 : 
                               1914             174 :     orig_nworkers_for_balance =
                               1915             174 :         pg_atomic_read_u32(&AutoVacuumShmem->av_nworkersForBalance);
 5837 alvherre                 1916 ECB             : 
 3827 alvherre                 1917 CBC         332 :     dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
 5837 alvherre                 1918 ECB             :     {
 3602 bruce                    1919 GIC         158 :         WorkerInfo  worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
                               1920                 : 
    2 dgustafsson              1921 GNC         316 :         if (worker->wi_proc == NULL ||
                               1922             158 :             pg_atomic_unlocked_test_flag(&worker->wi_dobalance))
    2 dgustafsson              1923 UNC           0 :             continue;
                               1924                 : 
    2 dgustafsson              1925 GNC         158 :         nworkers_for_balance++;
                               1926                 :     }
    2 dgustafsson              1927 ECB             : 
    2 dgustafsson              1928 GNC         174 :     if (nworkers_for_balance != orig_nworkers_for_balance)
                               1929              26 :         pg_atomic_write_u32(&AutoVacuumShmem->av_nworkersForBalance,
                               1930                 :                             nworkers_for_balance);
 5837 alvherre                 1931 GIC         174 : }
 5837 alvherre                 1932 ECB             : 
 5837 alvherre                 1933 EUB             : /*
                               1934                 :  * get_database_list
                               1935                 :  *      Return a list of all databases found in pg_database.
                               1936                 :  *
                               1937                 :  * The list and associated data is allocated in the caller's memory context,
 4535 alvherre                 1938 ECB             :  * which is in charge of ensuring that it's properly cleaned up afterwards.
 4535 alvherre                 1939 EUB             :  *
                               1940                 :  * Note: this is the only function in which the autovacuum launcher uses a
 4969 tgl                      1941 ECB             :  * transaction.  Although we aren't attached to any particular database and
                               1942                 :  * therefore can't access most catalogs, we do have enough infrastructure
                               1943                 :  * to do a seqscan on pg_database.
 6478                          1944                 :  */
 6478 tgl                      1945 EUB             : static List *
 5837 alvherre                 1946 GIC         377 : get_database_list(void)
 6478 tgl                      1947 ECB             : {
 6385 bruce                    1948 GIC         377 :     List       *dblist = NIL;
 4969 tgl                      1949 ECB             :     Relation    rel;
                               1950                 :     TableScanDesc scan;
                               1951                 :     HeapTuple   tup;
 4382 bruce                    1952                 :     MemoryContext resultcxt;
 4535 alvherre                 1953 EUB             : 
                               1954                 :     /* This is the context that we will allocate our output data in */
 4535 alvherre                 1955 CBC         377 :     resultcxt = CurrentMemoryContext;
                               1956                 : 
                               1957                 :     /*
                               1958                 :      * Start a transaction so we can access pg_database, and get a snapshot.
                               1959                 :      * We don't have a use for the snapshot itself, but we're interested in
                               1960                 :      * the secondary effect that it sets RecentGlobalXmin.  (This is critical
                               1961                 :      * for anything that reads heap pages, because HOT may decide to prune
                               1962                 :      * them even if the process doesn't attempt to modify any tuples.)
                               1963                 :      *
                               1964                 :      * FIXME: This comment is inaccurate / the code buggy. A snapshot that is
                               1965                 :      * not pushed/active does not reliably prevent HOT pruning (->xmin could
                               1966                 :      * e.g. be cleared when cache invalidations are processed).
                               1967                 :      */
 4969 tgl                      1968             377 :     StartTransactionCommand();
 4969 tgl                      1969 GIC         377 :     (void) GetTransactionSnapshot();
                               1970                 : 
 1539 andres                   1971             377 :     rel = table_open(DatabaseRelationId, AccessShareLock);
 1490 andres                   1972 CBC         377 :     scan = table_beginscan_catalog(rel, 0, NULL);
                               1973                 : 
 4969 tgl                      1974            1698 :     while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
                               1975                 :     {
                               1976            1321 :         Form_pg_database pgdatabase = (Form_pg_database) GETSTRUCT(tup);
 4790 bruce                    1977 ECB             :         avw_dbase  *avdb;
                               1978                 :         MemoryContext oldcxt;
 4535 alvherre                 1979                 : 
                               1980                 :         /*
 4382 bruce                    1981                 :          * Allocate our results in the caller's context, not the
                               1982                 :          * transaction's. We do this inside the loop, and restore the original
                               1983                 :          * context at the end, so that leaky things like heap_getnext() are
                               1984                 :          * not called in a potentially long-lived context.
 4535 alvherre                 1985 EUB             :          */
 4535 alvherre                 1986 GIC        1321 :         oldcxt = MemoryContextSwitchTo(resultcxt);
 6478 tgl                      1987 ECB             : 
 5837 alvherre                 1988 GIC        1321 :         avdb = (avw_dbase *) palloc(sizeof(avw_dbase));
                               1989                 : 
 1601 andres                   1990 CBC        1321 :         avdb->adw_datid = pgdatabase->oid;
 4969 tgl                      1991            1321 :         avdb->adw_name = pstrdup(NameStr(pgdatabase->datname));
 4969 tgl                      1992 GIC        1321 :         avdb->adw_frozenxid = pgdatabase->datfrozenxid;
 3492 alvherre                 1993 CBC        1321 :         avdb->adw_minmulti = pgdatabase->datminmxid;
                               1994                 :         /* this gets set later: */
 5837 alvherre                 1995 GIC        1321 :         avdb->adw_entry = NULL;
                               1996                 : 
 5857                          1997            1321 :         dblist = lappend(dblist, avdb);
 4535                          1998            1321 :         MemoryContextSwitchTo(oldcxt);
                               1999                 :     }
                               2000                 : 
 1490 andres                   2001             377 :     table_endscan(scan);
 1539                          2002             377 :     table_close(rel, AccessShareLock);
                               2003                 : 
 4969 tgl                      2004             377 :     CommitTransactionCommand();
                               2005                 : 
                               2006                 :     /* Be sure to restore caller's memory context */
  221                          2007             377 :     MemoryContextSwitchTo(resultcxt);
  221 tgl                      2008 ECB             : 
 6478 tgl                      2009 GIC         377 :     return dblist;
 6478 tgl                      2010 ECB             : }
                               2011                 : 
                               2012                 : /*
                               2013                 :  * Process a database table-by-table
                               2014                 :  *
                               2015                 :  * Note that CHECK_FOR_INTERRUPTS is supposed to be used in certain spots in
                               2016                 :  * order not to ignore shutdown commands for too long.
                               2017                 :  */
                               2018                 : static void
 5856 alvherre                 2019 GIC          16 : do_autovacuum(void)
                               2020                 : {
                               2021                 :     Relation    classRel;
                               2022                 :     HeapTuple   tuple;
                               2023                 :     TableScanDesc relScan;
                               2024                 :     Form_pg_database dbForm;
                               2025              16 :     List       *table_oids = NIL;
 2330 rhaas                    2026              16 :     List       *orphan_oids = NIL;
                               2027                 :     HASHCTL     ctl;
                               2028                 :     HTAB       *table_toast_map;
                               2029                 :     ListCell   *volatile cell;
 5793 tgl                      2030 ECB             :     BufferAccessStrategy bstrategy;
 5050 bruce                    2031                 :     ScanKeyData key;
                               2032                 :     TupleDesc   pg_class_desc;
 2893 rhaas                    2033                 :     int         effective_multixact_freeze_max_age;
 2270 rhaas                    2034 CBC          16 :     bool        did_vacuum = false;
 2270 rhaas                    2035 GIC          16 :     bool        found_concurrent_worker = false;
 2063 alvherre                 2036 ECB             :     int         i;
                               2037                 : 
 5762                          2038                 :     /*
                               2039                 :      * StartTransactionCommand and CommitTransactionCommand will automatically
                               2040                 :      * switch to other contexts.  We need this one to keep the list of
                               2041                 :      * relations to vacuum/analyze across transactions.
                               2042                 :      */
 5762 alvherre                 2043 GIC          16 :     AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
                               2044                 :                                           "Autovacuum worker",
                               2045                 :                                           ALLOCSET_DEFAULT_SIZES);
                               2046              16 :     MemoryContextSwitchTo(AutovacMemCxt);
                               2047                 : 
 6478 tgl                      2048 ECB             :     /* Start a transaction so our commands have one to play into. */
 6478 tgl                      2049 GIC          16 :     StartTransactionCommand();
 6478 tgl                      2050 ECB             : 
                               2051                 :     /*
 2893 rhaas                    2052                 :      * Compute the multixact age for which freezing is urgent.  This is
 2878 bruce                    2053                 :      * normally autovacuum_multixact_freeze_max_age, but may be less if we are
                               2054                 :      * short of multixact member space.
 2893 rhaas                    2055                 :      */
 2893 rhaas                    2056 GIC          16 :     effective_multixact_freeze_max_age = MultiXactMemberFreezeThreshold();
 2893 rhaas                    2057 ECB             : 
                               2058                 :     /*
 5050 bruce                    2059                 :      * Find the pg_database entry and select the default freeze ages. We use
                               2060                 :      * zero in template and nonconnectable databases, else the system-wide
                               2061                 :      * default.
                               2062                 :      */
 4802 rhaas                    2063 CBC          16 :     tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
 5999 tgl                      2064              16 :     if (!HeapTupleIsValid(tuple))
 5999 tgl                      2065 UIC           0 :         elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
 5999 tgl                      2066 CBC          16 :     dbForm = (Form_pg_database) GETSTRUCT(tuple);
                               2067                 : 
 5999 tgl                      2068 GIC          16 :     if (dbForm->datistemplate || !dbForm->datallowconn)
 5196 heikki.linnakangas       2069 ECB             :     {
 5999 tgl                      2070 GIC           3 :         default_freeze_min_age = 0;
 5196 heikki.linnakangas       2071 CBC           3 :         default_freeze_table_age = 0;
 3342 alvherre                 2072 GIC           3 :         default_multixact_freeze_min_age = 0;
                               2073               3 :         default_multixact_freeze_table_age = 0;
                               2074                 :     }
                               2075                 :     else
                               2076                 :     {
 5999 tgl                      2077              13 :         default_freeze_min_age = vacuum_freeze_min_age;
 5196 heikki.linnakangas       2078              13 :         default_freeze_table_age = vacuum_freeze_table_age;
 3342 alvherre                 2079              13 :         default_multixact_freeze_min_age = vacuum_multixact_freeze_min_age;
                               2080              13 :         default_multixact_freeze_table_age = vacuum_multixact_freeze_table_age;
 5196 heikki.linnakangas       2081 ECB             :     }
                               2082                 : 
 5999 tgl                      2083 GIC          16 :     ReleaseSysCache(tuple);
                               2084                 : 
                               2085                 :     /* StartTransactionCommand changed elsewhere */
 6478                          2086              16 :     MemoryContextSwitchTo(AutovacMemCxt);
 6478 tgl                      2087 ECB             : 
 1539 andres                   2088 CBC          16 :     classRel = table_open(RelationRelationId, AccessShareLock);
                               2089                 : 
                               2090                 :     /* create a copy so we can use it after closing pg_class */
 5172 alvherre                 2091 GIC          16 :     pg_class_desc = CreateTupleDescCopy(RelationGetDescr(classRel));
                               2092                 : 
                               2093                 :     /* create hash table for toast <-> main relid mapping */
 5352                          2094              16 :     ctl.keysize = sizeof(Oid);
 5172                          2095              16 :     ctl.entrysize = sizeof(av_relation);
 5352 alvherre                 2096 ECB             : 
 5352 alvherre                 2097 CBC          16 :     table_toast_map = hash_create("TOAST to main relid map",
                               2098                 :                                   100,
                               2099                 :                                   &ctl,
                               2100                 :                                   HASH_ELEM | HASH_BLOBS);
                               2101                 : 
                               2102                 :     /*
                               2103                 :      * Scan pg_class to determine which tables to vacuum.
                               2104                 :      *
  601 alvherre                 2105 ECB             :      * We do this in two passes: on the first one we collect the list of plain
                               2106                 :      * relations and materialized views, and on the second one we collect
                               2107                 :      * TOAST tables. The reason for doing the second pass is that during it we
                               2108                 :      * want to use the main relation's pg_class.reloptions entry if the TOAST
                               2109                 :      * table does not have any, and we cannot obtain it unless we know
                               2110                 :      * beforehand what's the main table OID.
 6446 tgl                      2111                 :      *
                               2112                 :      * We need to check TOAST tables separately because in cases with short,
                               2113                 :      * wide tables there might be proportionally much more activity in the
                               2114                 :      * TOAST table than in its parent.
                               2115                 :      */
 1490 andres                   2116 GIC          16 :     relScan = table_beginscan_catalog(classRel, 0, NULL);
                               2117                 : 
 5352 alvherre                 2118 ECB             :     /*
                               2119                 :      * On the first pass, we collect main tables to vacuum, and also the main
                               2120                 :      * table relid to TOAST relid mapping.
                               2121                 :      */
 6450 tgl                      2122 GIC        7857 :     while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
                               2123                 :     {
                               2124            7841 :         Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
 6450 tgl                      2125 ECB             :         PgStat_StatTabEntry *tabentry;
 5172 alvherre                 2126                 :         AutoVacOpts *relopts;
 6450 tgl                      2127 EUB             :         Oid         relid;
 5395 tgl                      2128 ECB             :         bool        dovacuum;
                               2129                 :         bool        doanalyze;
                               2130                 :         bool        wraparound;
                               2131                 : 
 3689 kgrittn                  2132 CBC        7841 :         if (classForm->relkind != RELKIND_RELATION &&
  601 alvherre                 2133            6277 :             classForm->relkind != RELKIND_MATVIEW)
 3689 kgrittn                  2134            6255 :             continue;
 3689 kgrittn                  2135 ECB             : 
 1601 andres                   2136 GIC        1586 :         relid = classForm->oid;
                               2137                 : 
                               2138                 :         /*
 5395 tgl                      2139 ECB             :          * Check if it is a temp table (presumably, of some other backend's).
                               2140                 :          * We cannot safely process other backends' temp tables.
                               2141                 :          */
 4500 rhaas                    2142 CBC        1586 :         if (classForm->relpersistence == RELPERSISTENCE_TEMP)
                               2143                 :         {
                               2144                 :             /*
 1700 michael                  2145 ECB             :              * We just ignore it if the owning backend is still active and
                               2146                 :              * using the temporary schema.  Also, for safety, ignore it if the
                               2147                 :              * namespace doesn't exist or isn't a temp namespace after all.
                               2148                 :              */
 1136 tgl                      2149 UIC           0 :             if (checkTempNamespaceStatus(classForm->relnamespace) == TEMP_NAMESPACE_IDLE)
 5395 tgl                      2150 ECB             :             {
                               2151                 :                 /*
                               2152                 :                  * The table seems to be orphaned -- although it might be that
 2324                          2153                 :                  * the owning backend has already deleted it and exited; our
                               2154                 :                  * pg_class scan snapshot is not necessarily up-to-date
                               2155                 :                  * anymore, so we could be looking at a committed-dead entry.
                               2156                 :                  * Remember it so we can try to delete it later.
 5395                          2157                 :                  */
 2330 rhaas                    2158 UIC           0 :                 orphan_oids = lappend_oid(orphan_oids, relid);
 5395 tgl                      2159 ECB             :             }
 2324 tgl                      2160 UIC           0 :             continue;
                               2161                 :         }
                               2162                 : 
                               2163                 :         /* Fetch reloptions and the pgstat entry for this table */
 2324 tgl                      2164 GIC        1586 :         relopts = extract_autovac_opts(tuple, pg_class_desc);
  368 andres                   2165            1586 :         tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
                               2166                 :                                                   relid);
                               2167                 : 
                               2168                 :         /* Check if it needs vacuum or analyze */
 2324 tgl                      2169            1586 :         relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
                               2170                 :                                   effective_multixact_freeze_max_age,
                               2171                 :                                   &dovacuum, &doanalyze, &wraparound);
                               2172                 : 
                               2173                 :         /* Relations that need work are added to table_oids */
                               2174            1586 :         if (dovacuum || doanalyze)
                               2175             158 :             table_oids = lappend_oid(table_oids, relid);
                               2176                 : 
                               2177                 :         /*
 2324 tgl                      2178 ECB             :          * Remember TOAST associations for the second pass.  Note: we must do
                               2179                 :          * this whether or not the table is going to be vacuumed, because we
                               2180                 :          * don't automatically vacuum toast tables along the parent table.
                               2181                 :          */
 2324 tgl                      2182 GIC        1586 :         if (OidIsValid(classForm->reltoastrelid))
                               2183                 :         {
 2324 tgl                      2184 ECB             :             av_relation *hentry;
                               2185                 :             bool        found;
 5395                          2186                 : 
 2324 tgl                      2187 GIC        1652 :             hentry = hash_search(table_toast_map,
                               2188             826 :                                  &classForm->reltoastrelid,
                               2189                 :                                  HASH_ENTER, &found);
                               2190                 : 
                               2191             826 :             if (!found)
                               2192                 :             {
                               2193                 :                 /* hash_search already filled in the key */
 2324 tgl                      2194 CBC         826 :                 hentry->ar_relid = relid;
                               2195             826 :                 hentry->ar_hasrelopts = false;
                               2196             826 :                 if (relopts != NULL)
                               2197                 :                 {
                               2198               7 :                     hentry->ar_hasrelopts = true;
 2324 tgl                      2199 GIC           7 :                     memcpy(&hentry->ar_reloptions, relopts,
                               2200                 :                            sizeof(AutoVacOpts));
                               2201                 :                 }
                               2202                 :             }
                               2203                 :         }
 6450 tgl                      2204 ECB             :     }
                               2205                 : 
 1490 andres                   2206 GIC          16 :     table_endscan(relScan);
                               2207                 : 
                               2208                 :     /* second pass: check TOAST tables */
 5352 alvherre                 2209              16 :     ScanKeyInit(&key,
                               2210                 :                 Anum_pg_class_relkind,
 5352 alvherre                 2211 EUB             :                 BTEqualStrategyNumber, F_CHAREQ,
                               2212                 :                 CharGetDatum(RELKIND_TOASTVALUE));
                               2213                 : 
 1490 andres                   2214 GIC          16 :     relScan = table_beginscan_catalog(classRel, 1, &key);
 5352 alvherre                 2215             842 :     while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
                               2216                 :     {
                               2217             826 :         Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
                               2218                 :         PgStat_StatTabEntry *tabentry;
                               2219                 :         Oid         relid;
 5172 alvherre                 2220 GBC         826 :         AutoVacOpts *relopts = NULL;
                               2221                 :         bool        dovacuum;
 5352 alvherre                 2222 EUB             :         bool        doanalyze;
                               2223                 :         bool        wraparound;
                               2224                 : 
                               2225                 :         /*
 5122 tgl                      2226 ECB             :          * We cannot safely process other backends' temp tables, so skip 'em.
 5352 alvherre                 2227                 :          */
 4500 rhaas                    2228 GIC         826 :         if (classForm->relpersistence == RELPERSISTENCE_TEMP)
 5352 alvherre                 2229 UIC           0 :             continue;
                               2230                 : 
 1601 andres                   2231 CBC         826 :         relid = classForm->oid;
                               2232                 : 
                               2233                 :         /*
                               2234                 :          * fetch reloptions -- if this toast table does not have them, try the
                               2235                 :          * main rel
 5172 alvherre                 2236 ECB             :          */
 5172 alvherre                 2237 CBC         826 :         relopts = extract_autovac_opts(tuple, pg_class_desc);
 5172 alvherre                 2238 GIC         826 :         if (relopts == NULL)
                               2239                 :         {
                               2240                 :             av_relation *hentry;
                               2241                 :             bool        found;
                               2242                 : 
                               2243             826 :             hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
 5172 alvherre                 2244 CBC         826 :             if (found && hentry->ar_hasrelopts)
 5172 alvherre                 2245 GIC           7 :                 relopts = &hentry->ar_reloptions;
                               2246                 :         }
                               2247                 : 
                               2248                 :         /* Fetch the pgstat entry for this table */
  368 andres                   2249 CBC         826 :         tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
  368 andres                   2250 ECB             :                                                   relid);
                               2251                 : 
 5172 alvherre                 2252 GIC         826 :         relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
 2893 rhaas                    2253 ECB             :                                   effective_multixact_freeze_max_age,
                               2254                 :                                   &dovacuum, &doanalyze, &wraparound);
                               2255                 : 
 5352 alvherre                 2256                 :         /* ignore analyze for toast tables */
 5352 alvherre                 2257 CBC         826 :         if (dovacuum)
 5352 alvherre                 2258 LBC           0 :             table_oids = lappend_oid(table_oids, relid);
                               2259                 :     }
 5856 alvherre                 2260 ECB             : 
 1490 andres                   2261 CBC          16 :     table_endscan(relScan);
 1539 andres                   2262 GIC          16 :     table_close(classRel, AccessShareLock);
                               2263                 : 
                               2264                 :     /*
                               2265                 :      * Recheck orphan temporary tables, and if they still seem orphaned, drop
                               2266                 :      * them.  We'll eat a transaction per dropped table, which might seem
                               2267                 :      * excessive, but we should only need to do anything as a result of a
 2324 tgl                      2268 ECB             :      * previous backend crash, so this should not happen often enough to
                               2269                 :      * justify "optimizing".  Using separate transactions ensures that we
                               2270                 :      * don't bloat the lock table if there are many temp tables to be dropped,
                               2271                 :      * and it ensures that we don't lose work if a deletion attempt fails.
                               2272                 :      */
 2324 tgl                      2273 GIC          16 :     foreach(cell, orphan_oids)
                               2274                 :     {
 2324 tgl                      2275 UIC           0 :         Oid         relid = lfirst_oid(cell);
 2324 tgl                      2276 ECB             :         Form_pg_class classForm;
                               2277                 :         ObjectAddress object;
                               2278                 : 
                               2279                 :         /*
                               2280                 :          * Check for user-requested abort.
                               2281                 :          */
 2324 tgl                      2282 LBC           0 :         CHECK_FOR_INTERRUPTS();
                               2283                 : 
                               2284                 :         /*
                               2285                 :          * Try to lock the table.  If we can't get the lock immediately,
                               2286                 :          * somebody else is using (or dropping) the table, so it's not our
                               2287                 :          * concern anymore.  Having the lock prevents race conditions below.
                               2288                 :          */
 2324 tgl                      2289 UIC           0 :         if (!ConditionalLockRelationOid(relid, AccessExclusiveLock))
 2324 tgl                      2290 LBC           0 :             continue;
 2330 rhaas                    2291 EUB             : 
                               2292                 :         /*
 2324 tgl                      2293 ECB             :          * Re-fetch the pg_class tuple and re-check whether it still seems to
                               2294                 :          * be an orphaned temp table.  If it's not there or no longer the same
                               2295                 :          * relation, ignore it.
                               2296                 :          */
 2324 tgl                      2297 UIC           0 :         tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
                               2298               0 :         if (!HeapTupleIsValid(tuple))
 2330 rhaas                    2299 ECB             :         {
 2324 tgl                      2300                 :             /* be sure to drop useless lock so we don't bloat lock table */
 2324 tgl                      2301 UIC           0 :             UnlockRelationOid(relid, AccessExclusiveLock);
                               2302               0 :             continue;
                               2303                 :         }
                               2304               0 :         classForm = (Form_pg_class) GETSTRUCT(tuple);
 2330 rhaas                    2305 ECB             : 
                               2306                 :         /*
 2324 tgl                      2307                 :          * Make all the same tests made in the loop above.  In event of OID
                               2308                 :          * counter wraparound, the pg_class entry we have now might be
                               2309                 :          * completely unrelated to the one we saw before.
                               2310                 :          */
 2324 tgl                      2311 LBC           0 :         if (!((classForm->relkind == RELKIND_RELATION ||
 2324 tgl                      2312 UIC           0 :                classForm->relkind == RELKIND_MATVIEW) &&
                               2313               0 :               classForm->relpersistence == RELPERSISTENCE_TEMP))
 2330 rhaas                    2314 ECB             :         {
 2324 tgl                      2315 UIC           0 :             UnlockRelationOid(relid, AccessExclusiveLock);
                               2316               0 :             continue;
                               2317                 :         }
                               2318                 : 
 1136 tgl                      2319 LBC           0 :         if (checkTempNamespaceStatus(classForm->relnamespace) != TEMP_NAMESPACE_IDLE)
 2324 tgl                      2320 EUB             :         {
 2324 tgl                      2321 UIC           0 :             UnlockRelationOid(relid, AccessExclusiveLock);
                               2322               0 :             continue;
 2330 rhaas                    2323 ECB             :         }
                               2324                 : 
                               2325                 :         /* OK, let's delete it */
 2324 tgl                      2326 UIC           0 :         ereport(LOG,
                               2327                 :                 (errmsg("autovacuum: dropping orphan temp table \"%s.%s.%s\"",
                               2328                 :                         get_database_name(MyDatabaseId),
                               2329                 :                         get_namespace_name(classForm->relnamespace),
                               2330                 :                         NameStr(classForm->relname))));
                               2331                 : 
                               2332               0 :         object.classId = RelationRelationId;
                               2333               0 :         object.objectId = relid;
                               2334               0 :         object.objectSubId = 0;
 2319 tgl                      2335 LBC           0 :         performDeletion(&object, DROP_CASCADE,
                               2336                 :                         PERFORM_DELETION_INTERNAL |
 2319 tgl                      2337 EUB             :                         PERFORM_DELETION_QUIETLY |
                               2338                 :                         PERFORM_DELETION_SKIP_EXTENSIONS);
                               2339                 : 
                               2340                 :         /*
                               2341                 :          * To commit the deletion, end current transaction and start a new
                               2342                 :          * one.  Note this also releases the lock we took.
                               2343                 :          */
 2330 rhaas                    2344 UBC           0 :         CommitTransactionCommand();
 2330 rhaas                    2345 UIC           0 :         StartTransactionCommand();
                               2346                 : 
                               2347                 :         /* StartTransactionCommand changed current memory context */
                               2348               0 :         MemoryContextSwitchTo(AutovacMemCxt);
                               2349                 :     }
                               2350                 : 
 5793 tgl                      2351 EUB             :     /*
                               2352                 :      * Optionally, create a buffer access strategy object for VACUUM to use.
                               2353                 :      * We use the same BufferAccessStrategy object for all tables VACUUMed by
                               2354                 :      * this worker to prevent autovacuum from blowing out shared buffers.
                               2355                 :      *
                               2356                 :      * VacuumBufferUsageLimit being set to 0 results in
                               2357                 :      * GetAccessStrategyWithSize returning NULL, effectively meaning we can
                               2358                 :      * use up to all of shared buffers.
                               2359                 :      *
                               2360                 :      * If we later enter failsafe mode on any of the tables being vacuumed, we
                               2361                 :      * will cease use of the BufferAccessStrategy only for that table.
                               2362                 :      *
                               2363                 :      * XXX should we consider adding code to adjust the size of this if
                               2364                 :      * VacuumBufferUsageLimit changes?
                               2365                 :      */
    2 drowley                  2366 GNC          16 :     bstrategy = GetAccessStrategyWithSize(BAS_VACUUM, VacuumBufferUsageLimit);
                               2367                 : 
                               2368                 :     /*
 5762 alvherre                 2369 EUB             :      * create a memory context to act as fake PortalContext, so that the
                               2370                 :      * contexts created in the vacuum code are cleaned up for each table.
                               2371                 :      */
 5762 alvherre                 2372 GIC          16 :     PortalContext = AllocSetContextCreate(AutovacMemCxt,
 5762 alvherre                 2373 EUB             :                                           "Autovacuum Portal",
 2416 tgl                      2374                 :                                           ALLOCSET_DEFAULT_SIZES);
                               2375                 : 
 6450                          2376                 :     /*
                               2377                 :      * Perform operations on collected tables.
                               2378                 :      */
 5856 alvherre                 2379 GIC         174 :     foreach(cell, table_oids)
                               2380                 :     {
 5624 bruce                    2381             158 :         Oid         relid = lfirst_oid(cell);
                               2382                 :         HeapTuple   classTup;
 5856 alvherre                 2383 EUB             :         autovac_table *tab;
 1853 tgl                      2384                 :         bool        isshared;
 5624 bruce                    2385                 :         bool        skipit;
 3827 alvherre                 2386                 :         dlist_iter  iter;
                               2387                 : 
 6463 tgl                      2388 GIC         158 :         CHECK_FOR_INTERRUPTS();
 6478 tgl                      2389 EUB             : 
                               2390                 :         /*
 2928 alvherre                 2391                 :          * Check for config changes before processing each collected table.
                               2392                 :          */
 1209 rhaas                    2393 GIC         158 :         if (ConfigReloadPending)
                               2394                 :         {
 1209 rhaas                    2395 UIC           0 :             ConfigReloadPending = false;
 2928 alvherre                 2396 UBC           0 :             ProcessConfigFile(PGC_SIGHUP);
                               2397                 : 
                               2398                 :             /*
                               2399                 :              * You might be tempted to bail out if we see autovacuum is now
                               2400                 :              * disabled.  Must resist that temptation -- this might be a
                               2401                 :              * for-wraparound emergency worker, in which case that would be
 2928 alvherre                 2402 EUB             :              * entirely inappropriate.
                               2403                 :              */
                               2404                 :         }
                               2405                 : 
                               2406                 :         /*
                               2407                 :          * Find out whether the table is shared or not.  (It's slightly
                               2408                 :          * annoying to fetch the syscache entry just for this, but in typical
                               2409                 :          * cases it adds little cost because table_recheck_autovac would
                               2410                 :          * refetch the entry anyway.  We could buy that back by copying the
                               2411                 :          * tuple here and passing it to table_recheck_autovac, but that
                               2412                 :          * increases the odds of that function working with stale data.)
                               2413                 :          */
 1853 tgl                      2414 GBC         158 :         classTup = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
                               2415             158 :         if (!HeapTupleIsValid(classTup))
 1853 tgl                      2416 UIC           0 :             continue;           /* somebody deleted the rel, forget it */
 1853 tgl                      2417 GIC         158 :         isshared = ((Form_pg_class) GETSTRUCT(classTup))->relisshared;
 1853 tgl                      2418 GBC         158 :         ReleaseSysCache(classTup);
                               2419                 : 
                               2420                 :         /*
                               2421                 :          * Hold schedule lock from here until we've claimed the table.  We
                               2422                 :          * also need the AutovacuumLock to walk the worker array, but that one
                               2423                 :          * can just be a shared lock.
                               2424                 :          */
 5837 alvherre                 2425 GIC         158 :         LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
                               2426             158 :         LWLockAcquire(AutovacuumLock, LW_SHARED);
                               2427                 : 
                               2428                 :         /*
                               2429                 :          * Check whether the table is being vacuumed concurrently by another
                               2430                 :          * worker.
                               2431                 :          */
                               2432             158 :         skipit = false;
 3827                          2433             316 :         dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
                               2434                 :         {
                               2435             158 :             WorkerInfo  worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
 3827 alvherre                 2436 ECB             : 
                               2437                 :             /* ignore myself */
 5837 alvherre                 2438 GIC         158 :             if (worker == MyWorkerInfo)
 3827                          2439             158 :                 continue;
                               2440                 : 
                               2441                 :             /* ignore workers in other databases (unless table is shared) */
 2525 alvherre                 2442 LBC           0 :             if (!worker->wi_sharedrel && worker->wi_dboid != MyDatabaseId)
 3827 alvherre                 2443 UIC           0 :                 continue;
                               2444                 : 
 5837                          2445               0 :             if (worker->wi_tableoid == relid)
                               2446                 :             {
                               2447               0 :                 skipit = true;
 2270 rhaas                    2448               0 :                 found_concurrent_worker = true;
 5837 alvherre                 2449 LBC           0 :                 break;
                               2450                 :             }
 5837 alvherre                 2451 ECB             :         }
 5837 alvherre                 2452 GIC         158 :         LWLockRelease(AutovacuumLock);
                               2453             158 :         if (skipit)
                               2454                 :         {
 5837 alvherre                 2455 UIC           0 :             LWLockRelease(AutovacuumScheduleLock);
                               2456               0 :             continue;
                               2457                 :         }
 5837 alvherre                 2458 ECB             : 
                               2459                 :         /*
                               2460                 :          * Store the table's OID in shared memory before releasing the
                               2461                 :          * schedule lock, so that other workers don't try to vacuum it
                               2462                 :          * concurrently.  (We claim it here so as not to hold
 1853 tgl                      2463                 :          * AutovacuumScheduleLock while rechecking the stats.)
                               2464                 :          */
 1853 tgl                      2465 GBC         158 :         MyWorkerInfo->wi_tableoid = relid;
                               2466             158 :         MyWorkerInfo->wi_sharedrel = isshared;
 1853 tgl                      2467 GIC         158 :         LWLockRelease(AutovacuumScheduleLock);
                               2468                 : 
                               2469                 :         /*
                               2470                 :          * Check whether pgstat data still says we need to vacuum this table.
                               2471                 :          * It could have changed if something else processed the table while
                               2472                 :          * we weren't looking. This doesn't entirely close the race condition,
                               2473                 :          * but it is very small.
                               2474                 :          */
 5762 alvherre                 2475             158 :         MemoryContextSwitchTo(AutovacMemCxt);
 2893 rhaas                    2476             158 :         tab = table_recheck_autovac(relid, table_toast_map, pg_class_desc,
                               2477                 :                                     effective_multixact_freeze_max_age);
 5856 alvherre                 2478             158 :         if (tab == NULL)
                               2479                 :         {
                               2480                 :             /* someone else vacuumed the table, or it went away */
 1853 tgl                      2481 UIC           0 :             LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
                               2482               0 :             MyWorkerInfo->wi_tableoid = InvalidOid;
                               2483               0 :             MyWorkerInfo->wi_sharedrel = false;
 5837 alvherre                 2484 LBC           0 :             LWLockRelease(AutovacuumScheduleLock);
 6446 tgl                      2485               0 :             continue;
 5856 alvherre                 2486 EUB             :         }
 6446 tgl                      2487 ECB             : 
    2 dgustafsson              2488                 :         /*
                               2489                 :          * Save the cost-related storage parameter values in global variables
                               2490                 :          * for reference when updating vacuum_cost_delay and vacuum_cost_limit
                               2491                 :          * during vacuuming this table.
                               2492                 :          */
    2 dgustafsson              2493 GNC         158 :         av_storage_param_cost_delay = tab->at_storage_param_vac_cost_delay;
                               2494             158 :         av_storage_param_cost_limit = tab->at_storage_param_vac_cost_limit;
 5646 alvherre                 2495 ECB             : 
                               2496                 :         /*
                               2497                 :          * We only expect this worker to ever set the flag, so don't bother
                               2498                 :          * checking the return value. We shouldn't have to retry.
                               2499                 :          */
    2 dgustafsson              2500 GNC         158 :         if (tab->at_dobalance)
                               2501             158 :             pg_atomic_test_set_flag(&MyWorkerInfo->wi_dobalance);
                               2502                 :         else
    2 dgustafsson              2503 UNC           0 :             pg_atomic_clear_flag(&MyWorkerInfo->wi_dobalance);
                               2504                 : 
    2 dgustafsson              2505 GNC         158 :         LWLockAcquire(AutovacuumLock, LW_SHARED);
                               2506             158 :         autovac_recalculate_workers_for_balance();
    2 dgustafsson              2507 GBC         158 :         LWLockRelease(AutovacuumLock);
 5646 alvherre                 2508 EUB             : 
                               2509                 :         /*
                               2510                 :          * We wait until this point to update cost delay and cost limit
                               2511                 :          * values, even though we reloaded the configuration file above, so
                               2512                 :          * that we can take into account the cost-related storage parameters.
                               2513                 :          */
    2 dgustafsson              2514 GNC         158 :         VacuumUpdateCosts();
                               2515                 : 
                               2516                 : 
                               2517                 :         /* clean up memory before each iteration */
 5762 alvherre                 2518 GBC         158 :         MemoryContextResetAndDeleteChildren(PortalContext);
                               2519                 : 
 5645 alvherre                 2520 EUB             :         /*
                               2521                 :          * Save the relation name for a possible error message, to avoid a
 3260 bruce                    2522                 :          * catalog lookup in case of an error.  If any of these return NULL,
                               2523                 :          * then the relation has been dropped since last we checked; skip it.
                               2524                 :          * Note: they must live in a long-lived memory context because we call
 5379 alvherre                 2525 ECB             :          * vacuum and analyze in different transactions.
 5645                          2526                 :          */
                               2527                 : 
 5379 alvherre                 2528 GBC         158 :         tab->at_relname = get_rel_name(tab->at_relid);
                               2529             158 :         tab->at_nspname = get_namespace_name(get_rel_namespace(tab->at_relid));
 5379 alvherre                 2530 GIC         158 :         tab->at_datname = get_database_name(MyDatabaseId);
                               2531             158 :         if (!tab->at_relname || !tab->at_nspname || !tab->at_datname)
 5379 alvherre                 2532 UIC           0 :             goto deleted;
                               2533                 : 
                               2534                 :         /*
                               2535                 :          * We will abort vacuuming the current table if something errors out,
                               2536                 :          * and continue with the next one in schedule; in particular, this
                               2537                 :          * happens if we are interrupted with SIGINT.
 5763 alvherre                 2538 ECB             :          */
 5763 alvherre                 2539 CBC         158 :         PG_TRY();
 5763 alvherre                 2540 ECB             :         {
                               2541                 :             /* Use PortalContext for any per-table allocations */
 2024 tgl                      2542 GIC         158 :             MemoryContextSwitchTo(PortalContext);
                               2543                 : 
                               2544                 :             /* have at it */
 5379 alvherre                 2545             158 :             autovacuum_do_vac_analyze(tab, bstrategy);
                               2546                 : 
                               2547                 :             /*
 5644 alvherre                 2548 ECB             :              * Clear a possible query-cancel signal, to avoid a late reaction
 5624 bruce                    2549                 :              * to an automatically-sent signal because of vacuuming the
                               2550                 :              * current table (we're done with it, so it would make no sense to
                               2551                 :              * cancel at this point.)
                               2552                 :              */
 5644 alvherre                 2553 GIC         158 :             QueryCancelPending = false;
 5763 alvherre                 2554 EUB             :         }
 5763 alvherre                 2555 UBC           0 :         PG_CATCH();
 5763 alvherre                 2556 EUB             :         {
                               2557                 :             /*
 5646                          2558                 :              * Abort the transaction, start a new one, and proceed with the
                               2559                 :              * next table in our list.
                               2560                 :              */
 5646 alvherre                 2561 UIC           0 :             HOLD_INTERRUPTS();
 1483 rhaas                    2562               0 :             if (tab->at_params.options & VACOPT_VACUUM)
 5646 alvherre                 2563               0 :                 errcontext("automatic vacuum of table \"%s.%s.%s\"",
                               2564                 :                            tab->at_datname, tab->at_nspname, tab->at_relname);
                               2565                 :             else
 5646 alvherre                 2566 LBC           0 :                 errcontext("automatic analyze of table \"%s.%s.%s\"",
 5379 alvherre                 2567 ECB             :                            tab->at_datname, tab->at_nspname, tab->at_relname);
 5646 alvherre                 2568 UIC           0 :             EmitErrorReport();
                               2569                 : 
                               2570                 :             /* this resets ProcGlobal->statusFlags[i] too */
                               2571               0 :             AbortOutOfAnyTransaction();
                               2572               0 :             FlushErrorState();
 5646 alvherre                 2573 LBC           0 :             MemoryContextResetAndDeleteChildren(PortalContext);
 5646 alvherre                 2574 ECB             : 
                               2575                 :             /* restart our transaction for the following operations */
 5646 alvherre                 2576 UBC           0 :             StartTransactionCommand();
 5646 alvherre                 2577 UIC           0 :             RESUME_INTERRUPTS();
 5763 alvherre                 2578 ECB             :         }
 5763 alvherre                 2579 CBC         158 :         PG_END_TRY();
 5763 alvherre                 2580 ECB             : 
                               2581                 :         /* Make sure we're back in AutovacMemCxt */
 2024 tgl                      2582 GIC         158 :         MemoryContextSwitchTo(AutovacMemCxt);
                               2583                 : 
 2270 rhaas                    2584             158 :         did_vacuum = true;
                               2585                 : 
                               2586                 :         /* ProcGlobal->statusFlags[i] are reset at the next end of xact */
 5646 alvherre                 2587 ECB             : 
                               2588                 :         /* be tidy */
 5379 alvherre                 2589 GIC         158 : deleted:
                               2590             158 :         if (tab->at_datname != NULL)
 5379 alvherre                 2591 CBC         158 :             pfree(tab->at_datname);
 5379 alvherre                 2592 GIC         158 :         if (tab->at_nspname != NULL)
                               2593             158 :             pfree(tab->at_nspname);
                               2594             158 :         if (tab->at_relname != NULL)
                               2595             158 :             pfree(tab->at_relname);
 5856                          2596             158 :         pfree(tab);
                               2597                 : 
                               2598                 :         /*
                               2599                 :          * Remove my info from shared memory.  We set wi_dobalance on the
                               2600                 :          * assumption that we are more likely than not to vacuum a table with
                               2601                 :          * no cost-related storage parameters next, so we want to claim our
                               2602                 :          * share of I/O as soon as possible to avoid thrashing the global
                               2603                 :          * balance.
 4524 tgl                      2604 ECB             :          */
 1853 tgl                      2605 GBC         158 :         LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
 5646 alvherre                 2606 GIC         158 :         MyWorkerInfo->wi_tableoid = InvalidOid;
 2525                          2607             158 :         MyWorkerInfo->wi_sharedrel = false;
 1853 tgl                      2608             158 :         LWLockRelease(AutovacuumScheduleLock);
    2 dgustafsson              2609 GNC         158 :         pg_atomic_test_set_flag(&MyWorkerInfo->wi_dobalance);
                               2610                 :     }
                               2611                 : 
 2199 alvherre                 2612 ECB             :     /*
                               2613                 :      * Perform additional work items, as requested by backends.
                               2614                 :      */
 2063 alvherre                 2615 CBC          16 :     LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
 2063 alvherre                 2616 GIC        4112 :     for (i = 0; i < NUM_WORKITEMS; i++)
                               2617                 :     {
                               2618            4096 :         AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
                               2619                 : 
                               2620            4096 :         if (!workitem->avw_used)
                               2621            4093 :             continue;
                               2622               3 :         if (workitem->avw_active)
 2063 alvherre                 2623 LBC           0 :             continue;
 1987 alvherre                 2624 GIC           3 :         if (workitem->avw_database != MyDatabaseId)
 1987 alvherre                 2625 UBC           0 :             continue;
                               2626                 : 
                               2627                 :         /* claim this one, and release lock while performing it */
 2063 alvherre                 2628 GIC           3 :         workitem->avw_active = true;
                               2629               3 :         LWLockRelease(AutovacuumLock);
                               2630                 : 
 2063 alvherre                 2631 GBC           3 :         perform_work_item(workitem);
 2199 alvherre                 2632 EUB             : 
                               2633                 :         /*
                               2634                 :          * Check for config changes before acquiring lock for further jobs.
                               2635                 :          */
 2063 alvherre                 2636 GBC           3 :         CHECK_FOR_INTERRUPTS();
 1209 rhaas                    2637 GIC           3 :         if (ConfigReloadPending)
 2199 alvherre                 2638 EUB             :         {
 1209 rhaas                    2639 UIC           0 :             ConfigReloadPending = false;
 2063 alvherre                 2640               0 :             ProcessConfigFile(PGC_SIGHUP);
    2 dgustafsson              2641 UNC           0 :             VacuumUpdateCosts();
 2199 alvherre                 2642 EUB             :         }
                               2643                 : 
 2063 alvherre                 2644 GBC           3 :         LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
                               2645                 : 
                               2646                 :         /* and mark it done */
                               2647               3 :         workitem->avw_active = false;
                               2648               3 :         workitem->avw_used = false;
                               2649                 :     }
 2063 alvherre                 2650 CBC          16 :     LWLockRelease(AutovacuumLock);
                               2651                 : 
                               2652                 :     /*
 5050 bruce                    2653 ECB             :      * We leak table_toast_map here (among other things), but since we're
                               2654                 :      * going away soon, it's not a problem.
 5352 alvherre                 2655                 :      */
                               2656                 : 
                               2657                 :     /*
                               2658                 :      * Update pg_database.datfrozenxid, and truncate pg_xact if possible. We
                               2659                 :      * only need to do this once, not after each table.
 2270 rhaas                    2660                 :      *
                               2661                 :      * Even if we didn't vacuum anything, it may still be important to do
                               2662                 :      * this, because one indirect effect of vac_update_datfrozenxid() is to
                               2663                 :      * update ShmemVariableCache->xidVacLimit.  That might need to be done
                               2664                 :      * even if we haven't vacuumed anything, because relations with older
                               2665                 :      * relfrozenxid values or other databases with older datfrozenxid values
                               2666                 :      * might have been dropped, allowing xidVacLimit to advance.
                               2667                 :      *
                               2668                 :      * However, it's also important not to do this blindly in all cases,
                               2669                 :      * because when autovacuum=off this will restart the autovacuum launcher.
                               2670                 :      * If we're not careful, an infinite loop can result, where workers find
                               2671                 :      * no work to do and restart the launcher, which starts another worker in
                               2672                 :      * the same database that finds no work to do.  To prevent that, we skip
                               2673                 :      * this if (1) we found no work to do and (2) we skipped at least one
                               2674                 :      * table due to concurrent autovacuum activity.  In that case, the other
                               2675                 :      * worker has already done it, or will do so when it finishes.
 5999 tgl                      2676                 :      */
 2270 rhaas                    2677 CBC          16 :     if (did_vacuum || !found_concurrent_worker)
                               2678              16 :         vac_update_datfrozenxid();
 5999 tgl                      2679 ECB             : 
 6478                          2680                 :     /* Finally close out the last transaction. */
 6478 tgl                      2681 GIC          16 :     CommitTransactionCommand();
                               2682              16 : }
                               2683                 : 
                               2684                 : /*
                               2685                 :  * Execute a previously registered work item.
 2199 alvherre                 2686 ECB             :  */
                               2687                 : static void
 2199 alvherre                 2688 GIC           3 : perform_work_item(AutoVacuumWorkItem *workitem)
 2199 alvherre                 2689 ECB             : {
 2199 alvherre                 2690 GIC           3 :     char       *cur_datname = NULL;
 2199 alvherre                 2691 CBC           3 :     char       *cur_nspname = NULL;
                               2692               3 :     char       *cur_relname = NULL;
 2199 alvherre                 2693 ECB             : 
 2199 alvherre                 2694 EUB             :     /*
 2199 alvherre                 2695 ECB             :      * Note we do not store table info in MyWorkerInfo, since this is not
 2199 alvherre                 2696 EUB             :      * vacuuming proper.
                               2697                 :      */
                               2698                 : 
 2199 alvherre                 2699 ECB             :     /*
                               2700                 :      * Save the relation name for a possible error message, to avoid a catalog
                               2701                 :      * lookup in case of an error.  If any of these return NULL, then the
 1987                          2702                 :      * relation has been dropped since last we checked; skip it.
                               2703                 :      */
 2024 tgl                      2704 GIC           3 :     Assert(CurrentMemoryContext == AutovacMemCxt);
                               2705                 : 
 2199 alvherre                 2706               3 :     cur_relname = get_rel_name(workitem->avw_relation);
 2199 alvherre                 2707 CBC           3 :     cur_nspname = get_namespace_name(get_rel_namespace(workitem->avw_relation));
                               2708               3 :     cur_datname = get_database_name(MyDatabaseId);
 2199 alvherre                 2709 GIC           3 :     if (!cur_relname || !cur_nspname || !cur_datname)
 2199 alvherre                 2710 UBC           0 :         goto deleted2;
 2199 alvherre                 2711 EUB             : 
 1507 alvherre                 2712 GBC           3 :     autovac_report_workitem(workitem, cur_nspname, cur_relname);
                               2713                 : 
                               2714                 :     /* clean up memory before each work item */
 2024 tgl                      2715 CBC           3 :     MemoryContextResetAndDeleteChildren(PortalContext);
                               2716                 : 
                               2717                 :     /*
 2199 alvherre                 2718 ECB             :      * We will abort the current work item if something errors out, and
                               2719                 :      * continue with the next one; in particular, this happens if we are
                               2720                 :      * interrupted with SIGINT.  Note that this means that the work item list
                               2721                 :      * can be lossy.
                               2722                 :      */
 2199 alvherre                 2723 GIC           3 :     PG_TRY();
                               2724                 :     {
                               2725                 :         /* Use PortalContext for any per-work-item allocations */
 2024 tgl                      2726               3 :         MemoryContextSwitchTo(PortalContext);
                               2727                 : 
                               2728                 :         /*
                               2729                 :          * Have at it.  Functions called here are responsible for any required
                               2730                 :          * user switch and sandbox.
                               2731                 :          */
 2199 alvherre                 2732               3 :         switch (workitem->avw_type)
                               2733                 :         {
                               2734               3 :             case AVW_BRINSummarizeRange:
                               2735               3 :                 DirectFunctionCall2(brin_summarize_range,
                               2736                 :                                     ObjectIdGetDatum(workitem->avw_relation),
                               2737                 :                                     Int64GetDatum((int64) workitem->avw_blockNumber));
                               2738               3 :                 break;
 2199 alvherre                 2739 UIC           0 :             default:
                               2740               0 :                 elog(WARNING, "unrecognized work item found: type %d",
                               2741                 :                      workitem->avw_type);
                               2742               0 :                 break;
                               2743                 :         }
                               2744                 : 
                               2745                 :         /*
                               2746                 :          * Clear a possible query-cancel signal, to avoid a late reaction to
                               2747                 :          * an automatically-sent signal because of vacuuming the current table
                               2748                 :          * (we're done with it, so it would make no sense to cancel at this
                               2749                 :          * point.)
                               2750                 :          */
 2199 alvherre                 2751 CBC           3 :         QueryCancelPending = false;
 2199 alvherre                 2752 ECB             :     }
 2199 alvherre                 2753 UIC           0 :     PG_CATCH();
                               2754                 :     {
 2199 alvherre                 2755 ECB             :         /*
                               2756                 :          * Abort the transaction, start a new one, and proceed with the next
                               2757                 :          * table in our list.
                               2758                 :          */
 2199 alvherre                 2759 UIC           0 :         HOLD_INTERRUPTS();
                               2760               0 :         errcontext("processing work entry for relation \"%s.%s.%s\"",
                               2761                 :                    cur_datname, cur_nspname, cur_relname);
 2199 alvherre                 2762 LBC           0 :         EmitErrorReport();
                               2763                 : 
  874 alvherre                 2764 ECB             :         /* this resets ProcGlobal->statusFlags[i] too */
 2199 alvherre                 2765 LBC           0 :         AbortOutOfAnyTransaction();
                               2766               0 :         FlushErrorState();
 2199 alvherre                 2767 UIC           0 :         MemoryContextResetAndDeleteChildren(PortalContext);
                               2768                 : 
                               2769                 :         /* restart our transaction for the following operations */
                               2770               0 :         StartTransactionCommand();
                               2771               0 :         RESUME_INTERRUPTS();
                               2772                 :     }
 2199 alvherre                 2773 GIC           3 :     PG_END_TRY();
                               2774                 : 
                               2775                 :     /* Make sure we're back in AutovacMemCxt */
 2024 tgl                      2776               3 :     MemoryContextSwitchTo(AutovacMemCxt);
                               2777                 : 
 2199 alvherre                 2778 ECB             :     /* We intentionally do not set did_vacuum here */
                               2779                 : 
                               2780                 :     /* be tidy */
 2199 alvherre                 2781 CBC           3 : deleted2:
                               2782               3 :     if (cur_datname)
                               2783               3 :         pfree(cur_datname);
 2199 alvherre                 2784 GBC           3 :     if (cur_nspname)
 2199 alvherre                 2785 GIC           3 :         pfree(cur_nspname);
 2199 alvherre                 2786 CBC           3 :     if (cur_relname)
 2199 alvherre                 2787 GIC           3 :         pfree(cur_relname);
                               2788               3 : }
 2199 alvherre                 2789 ECB             : 
                               2790                 : /*
                               2791                 :  * extract_autovac_opts
                               2792                 :  *
                               2793                 :  * Given a relation's pg_class tuple, return the AutoVacOpts portion of
                               2794                 :  * reloptions, if set; otherwise, return NULL.
                               2795                 :  *
                               2796                 :  * Note: callers do not have a relation lock on the table at this point,
  718                          2797                 :  * so the table could have been dropped, and its catalog rows gone, after
                               2798                 :  * we acquired the pg_class row.  If pg_class had a TOAST table, this would
                               2799                 :  * be a risk; fortunately, it doesn't.
 5861                          2800                 :  */
                               2801                 : static AutoVacOpts *
 5172 alvherre                 2802 GIC        2570 : extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc)
                               2803                 : {
                               2804                 :     bytea      *relopts;
                               2805                 :     AutoVacOpts *av;
 5861 alvherre                 2806 ECB             : 
 5172 alvherre                 2807 GIC        2570 :     Assert(((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_RELATION ||
 3689 kgrittn                  2808 ECB             :            ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_MATVIEW ||
 5172 alvherre                 2809                 :            ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_TOASTVALUE);
                               2810                 : 
 2639 tgl                      2811 GIC        2570 :     relopts = extractRelOptions(tup, pg_class_desc, NULL);
 5172 alvherre                 2812 CBC        2570 :     if (relopts == NULL)
 5172 alvherre                 2813 GBC        2551 :         return NULL;
 5050 bruce                    2814 EUB             : 
 5172 alvherre                 2815 GIC          19 :     av = palloc(sizeof(AutoVacOpts));
 5172 alvherre                 2816 GBC          19 :     memcpy(av, &(((StdRdOptions *) relopts)->autovacuum), sizeof(AutoVacOpts));
 5172 alvherre                 2817 GIC          19 :     pfree(relopts);
                               2818                 : 
                               2819              19 :     return av;
                               2820                 : }
                               2821                 : 
                               2822                 : 
                               2823                 : /*
                               2824                 :  * table_recheck_autovac
 5856 alvherre                 2825 ECB             :  *
                               2826                 :  * Recheck whether a table still needs vacuum or analyze.  Return value is a
 5352 alvherre                 2827 EUB             :  * valid autovac_table pointer if it does, NULL otherwise.
                               2828                 :  *
                               2829                 :  * Note that the returned autovac_table does not have the name fields set.
                               2830                 :  */
                               2831                 : static autovac_table *
 5172 alvherre                 2832 GIC         158 : table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 2893 rhaas                    2833 EUB             :                       TupleDesc pg_class_desc,
                               2834                 :                       int effective_multixact_freeze_max_age)
                               2835                 : {
 5856 alvherre                 2836                 :     Form_pg_class classForm;
                               2837                 :     HeapTuple   classTup;
                               2838                 :     bool        dovacuum;
                               2839                 :     bool        doanalyze;
 5856 alvherre                 2840 GBC         158 :     autovac_table *tab = NULL;
 5352 alvherre                 2841 EUB             :     bool        wraparound;
                               2842                 :     AutoVacOpts *avopts;
                               2843                 : 
 5856                          2844                 :     /* fetch the relation's relcache entry */
 4802 rhaas                    2845 GBC         158 :     classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
 5856 alvherre                 2846 GIC         158 :     if (!HeapTupleIsValid(classTup))
 5856 alvherre                 2847 LBC           0 :         return NULL;
 5856 alvherre                 2848 GIC         158 :     classForm = (Form_pg_class) GETSTRUCT(classTup);
                               2849                 : 
 5050 bruce                    2850 ECB             :     /*
                               2851                 :      * Get the applicable reloptions.  If it is a TOAST table, try to get the
                               2852                 :      * main table reloptions if the toast table itself doesn't have.
                               2853                 :      */
 5172 alvherre                 2854 GIC         158 :     avopts = extract_autovac_opts(classTup, pg_class_desc);
 5050 bruce                    2855 CBC         158 :     if (classForm->relkind == RELKIND_TOASTVALUE &&
 5172 alvherre                 2856 LBC           0 :         avopts == NULL && table_toast_map != NULL)
 5172 alvherre                 2857 ECB             :     {
 5050 bruce                    2858                 :         av_relation *hentry;
                               2859                 :         bool        found;
 5352 alvherre                 2860                 : 
 5172 alvherre                 2861 LBC           0 :         hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
                               2862               0 :         if (found && hentry->ar_hasrelopts)
 5172 alvherre                 2863 UIC           0 :             avopts = &hentry->ar_reloptions;
                               2864                 :     }
                               2865                 : 
  852 fujii                    2866 GIC         158 :     recheck_relation_needs_vacanalyze(relid, avopts, classForm,
                               2867                 :                                       effective_multixact_freeze_max_age,
                               2868                 :                                       &dovacuum, &doanalyze, &wraparound);
                               2869                 : 
                               2870                 :     /* OK, it needs something done */
 5352 alvherre                 2871             158 :     if (doanalyze || dovacuum)
                               2872                 :     {
                               2873                 :         int         freeze_min_age;
                               2874                 :         int         freeze_table_age;
                               2875                 :         int         multixact_freeze_min_age;
 3342 alvherre                 2876 ECB             :         int         multixact_freeze_table_age;
                               2877                 :         int         log_min_duration;
                               2878                 : 
 5856                          2879                 :         /*
                               2880                 :          * Calculate the vacuum cost parameters and the freeze ages.  If there
                               2881                 :          * are options set in pg_class.reloptions, use them; in the case of a
                               2882                 :          * toast table, try the main table too.  Otherwise use the GUC
 5172                          2883                 :          * defaults, autovacuum's own first and plain vacuum second.
 5856                          2884                 :          */
 4973                          2885                 : 
                               2886                 :         /* -1 in autovac setting means use log_autovacuum_min_duration */
 2928 alvherre                 2887 GIC           1 :         log_min_duration = (avopts && avopts->log_min_duration >= 0)
                               2888                 :             ? avopts->log_min_duration
                               2889             159 :             : Log_autovacuum_min_duration;
 2928 alvherre                 2890 ECB             : 
                               2891                 :         /* these do not have autovacuum-specific settings */
 4973 alvherre                 2892 GIC           1 :         freeze_min_age = (avopts && avopts->freeze_min_age >= 0)
                               2893                 :             ? avopts->freeze_min_age
                               2894             159 :             : default_freeze_min_age;
                               2895                 : 
                               2896               1 :         freeze_table_age = (avopts && avopts->freeze_table_age >= 0)
                               2897                 :             ? avopts->freeze_table_age
 4973 alvherre                 2898 CBC         159 :             : default_freeze_table_age;
                               2899                 : 
 3342 alvherre                 2900 GIC         159 :         multixact_freeze_min_age = (avopts &&
                               2901               1 :                                     avopts->multixact_freeze_min_age >= 0)
                               2902                 :             ? avopts->multixact_freeze_min_age
 3342 alvherre                 2903 CBC         159 :             : default_multixact_freeze_min_age;
 3342 alvherre                 2904 ECB             : 
 3342 alvherre                 2905 GBC         159 :         multixact_freeze_table_age = (avopts &&
 3342 alvherre                 2906 CBC           1 :                                       avopts->multixact_freeze_table_age >= 0)
                               2907                 :             ? avopts->multixact_freeze_table_age
 3342 alvherre                 2908 GIC         159 :             : default_multixact_freeze_table_age;
                               2909                 : 
 5856                          2910             158 :         tab = palloc(sizeof(autovac_table));
                               2911             158 :         tab->at_relid = relid;
 2525 alvherre                 2912 CBC         158 :         tab->at_sharedrel = classForm->relisshared;
  789 michael                  2913 ECB             : 
                               2914                 :         /*
                               2915                 :          * Select VACUUM options.  Note we don't say VACOPT_PROCESS_TOAST, so
                               2916                 :          * that vacuum() skips toast relations.  Also note we tell vacuum() to
                               2917                 :          * skip vac_update_datfrozenxid(); we'll do that separately.
                               2918                 :          */
   93 tgl                      2919 GNC         158 :         tab->at_params.options =
   34 michael                  2920             158 :             (dovacuum ? (VACOPT_VACUUM |
                               2921                 :                          VACOPT_PROCESS_MAIN |
                               2922             158 :                          VACOPT_SKIP_DATABASE_STATS) : 0) |
 2944 alvherre                 2923 GIC         158 :             (doanalyze ? VACOPT_ANALYZE : 0) |
 1732 michael                  2924             158 :             (!wraparound ? VACOPT_SKIP_LOCKED : 0);
                               2925                 : 
  660 pg                       2926 EUB             :         /*
                               2927                 :          * index_cleanup and truncate are unspecified at first in autovacuum.
                               2928                 :          * They will be filled in with usable values using their reloptions
                               2929                 :          * (or reloption defaults) later.
                               2930                 :          */
  660 pg                       2931 CBC         158 :         tab->at_params.index_cleanup = VACOPTVALUE_UNSPECIFIED;
  660 pg                       2932 GIC         158 :         tab->at_params.truncate = VACOPTVALUE_UNSPECIFIED;
                               2933                 :         /* As of now, we don't support parallel vacuum for autovacuum */
 1175 akapila                  2934             158 :         tab->at_params.nworkers = -1;
 2944 alvherre                 2935             158 :         tab->at_params.freeze_min_age = freeze_min_age;
 2944 alvherre                 2936 CBC         158 :         tab->at_params.freeze_table_age = freeze_table_age;
 2944 alvherre                 2937 GIC         158 :         tab->at_params.multixact_freeze_min_age = multixact_freeze_min_age;
                               2938             158 :         tab->at_params.multixact_freeze_table_age = multixact_freeze_table_age;
                               2939             158 :         tab->at_params.is_wraparound = wraparound;
 2928                          2940             158 :         tab->at_params.log_min_duration = log_min_duration;
    2 dgustafsson              2941 GNC         158 :         tab->at_storage_param_vac_cost_limit = avopts ?
                               2942             158 :             avopts->vacuum_cost_limit : 0;
                               2943             158 :         tab->at_storage_param_vac_cost_delay = avopts ?
                               2944             158 :             avopts->vacuum_cost_delay : -1;
 5379 alvherre                 2945 GIC         158 :         tab->at_relname = NULL;
                               2946             158 :         tab->at_nspname = NULL;
                               2947             158 :         tab->at_datname = NULL;
                               2948                 : 
                               2949                 :         /*
                               2950                 :          * If any of the cost delay parameters has been set individually for
                               2951                 :          * this table, disable the balancing algorithm.
                               2952                 :          */
 3110                          2953             158 :         tab->at_dobalance =
 3110 alvherre                 2954 CBC         159 :             !(avopts && (avopts->vacuum_cost_limit > 0 ||
 3110 alvherre                 2955 GIC           1 :                          avopts->vacuum_cost_delay > 0));
 5856 alvherre                 2956 ECB             :     }
                               2957                 : 
 5856 alvherre                 2958 GIC         158 :     heap_freetuple(classTup);
 5856 alvherre                 2959 CBC         158 :     return tab;
                               2960                 : }
 5856 alvherre                 2961 ECB             : 
                               2962                 : /*
  852 fujii                    2963                 :  * recheck_relation_needs_vacanalyze
                               2964                 :  *
                               2965                 :  * Subroutine for table_recheck_autovac.
                               2966                 :  *
                               2967                 :  * Fetch the pgstat of a relation and recheck whether a relation
                               2968                 :  * needs to be vacuumed or analyzed.
                               2969                 :  */
                               2970                 : static void
  852 fujii                    2971 GIC         158 : recheck_relation_needs_vacanalyze(Oid relid,
  852 fujii                    2972 ECB             :                                   AutoVacOpts *avopts,
                               2973                 :                                   Form_pg_class classForm,
                               2974                 :                                   int effective_multixact_freeze_max_age,
                               2975                 :                                   bool *dovacuum,
                               2976                 :                                   bool *doanalyze,
                               2977                 :                                   bool *wraparound)
                               2978                 : {
                               2979                 :     PgStat_StatTabEntry *tabentry;
                               2980                 : 
                               2981                 :     /* fetch the pgstat table entry */
  368 andres                   2982 GIC         158 :     tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
                               2983                 :                                               relid);
                               2984                 : 
  852 fujii                    2985             158 :     relation_needs_vacanalyze(relid, avopts, classForm, tabentry,
  852 fujii                    2986 ECB             :                               effective_multixact_freeze_max_age,
                               2987                 :                               dovacuum, doanalyze, wraparound);
                               2988                 : 
                               2989                 :     /* ignore ANALYZE for toast tables */
  852 fujii                    2990 CBC         158 :     if (classForm->relkind == RELKIND_TOASTVALUE)
  852 fujii                    2991 LBC           0 :         *doanalyze = false;
  852 fujii                    2992 GIC         158 : }
                               2993                 : 
                               2994                 : /*
                               2995                 :  * relation_needs_vacanalyze
                               2996                 :  *
                               2997                 :  * Check whether a relation needs to be vacuumed or analyzed; return each into
 5646 alvherre                 2998 ECB             :  * "dovacuum" and "doanalyze", respectively.  Also return whether the vacuum is
 3342                          2999                 :  * being forced because of Xid or multixact wraparound.
                               3000                 :  *
 5172                          3001                 :  * relopts is a pointer to the AutoVacOpts options (either for itself in the
                               3002                 :  * case of a plain table, or for either itself or its parent table in the case
                               3003                 :  * of a TOAST table), NULL if none; tabentry is the pgstats entry, which can be
                               3004                 :  * NULL.
 6478 tgl                      3005                 :  *
                               3006                 :  * A table needs to be vacuumed if the number of dead tuples exceeds a
                               3007                 :  * threshold.  This threshold is calculated as
                               3008                 :  *
                               3009                 :  * threshold = vac_base_thresh + vac_scale_factor * reltuples
                               3010                 :  *
                               3011                 :  * For analyze, the analysis done is that the number of tuples inserted,
                               3012                 :  * deleted and updated since the last analyze exceeds a threshold calculated
  368 andres                   3013                 :  * in the same fashion as above.  Note that the cumulative stats system stores
 6478 tgl                      3014                 :  * the number of tuples (both live and dead) that there were as of the last
                               3015                 :  * analyze.  This is asymmetric to the VACUUM case.
                               3016                 :  *
                               3017                 :  * We also force vacuum if the table's relfrozenxid is more than freeze_max_age
                               3018                 :  * transactions back, and if its relminmxid is more than
                               3019                 :  * multixact_freeze_max_age multixacts back.
 5999                          3020                 :  *
 5172 alvherre                 3021                 :  * A table whose autovacuum_enabled option is false is
                               3022                 :  * automatically skipped (unless we have to vacuum it due to freeze_max_age).
                               3023                 :  * Thus autovacuum can be disabled for specific tables. Also, when the cumulative
                               3024                 :  * stats system does not have data about a table, it will be skipped.
 6478 tgl                      3025                 :  *
 5172 alvherre                 3026                 :  * A table whose vac_base_thresh value is < 0 takes the base value from the
                               3027                 :  * autovacuum_vacuum_threshold GUC variable.  Similarly, a vac_scale_factor
                               3028                 :  * value < 0 is substituted with the value of
                               3029                 :  * autovacuum_vacuum_scale_factor GUC variable.  Ditto for analyze.
                               3030                 :  */
                               3031                 : static void
 5856 alvherre                 3032 GIC        2570 : relation_needs_vacanalyze(Oid relid,
                               3033                 :                           AutoVacOpts *relopts,
                               3034                 :                           Form_pg_class classForm,
                               3035                 :                           PgStat_StatTabEntry *tabentry,
                               3036                 :                           int effective_multixact_freeze_max_age,
                               3037                 :  /* output params below */
 5856 alvherre                 3038 ECB             :                           bool *dovacuum,
                               3039                 :                           bool *doanalyze,
                               3040                 :                           bool *wraparound)
                               3041                 : {
                               3042                 :     bool        force_vacuum;
                               3043                 :     bool        av_enabled;
                               3044                 :     float4      reltuples;      /* pg_class.reltuples */
                               3045                 : 
                               3046                 :     /* constants from reloptions or GUC variables */
                               3047                 :     int         vac_base_thresh,
                               3048                 :                 vac_ins_base_thresh,
 6385 bruce                    3049                 :                 anl_base_thresh;
                               3050                 :     float4      vac_scale_factor,
                               3051                 :                 vac_ins_scale_factor,
                               3052                 :                 anl_scale_factor;
                               3053                 : 
                               3054                 :     /* thresholds calculated from above constants */
                               3055                 :     float4      vacthresh,
                               3056                 :                 vacinsthresh,
                               3057                 :                 anlthresh;
 5624 bruce                    3058 EUB             : 
 6478 tgl                      3059 ECB             :     /* number of vacuum (resp. analyze) tuples at this time */
                               3060                 :     float4      vactuples,
                               3061                 :                 instuples,
                               3062                 :                 anltuples;
                               3063                 : 
                               3064                 :     /* freeze parameters */
                               3065                 :     int         freeze_max_age;
                               3066                 :     int         multixact_freeze_max_age;
                               3067                 :     TransactionId xidForceLimit;
                               3068                 :     MultiXactId multiForceLimit;
                               3069                 : 
  163 peter                    3070 GNC        2570 :     Assert(classForm != NULL);
                               3071            2570 :     Assert(OidIsValid(relid));
                               3072                 : 
                               3073                 :     /*
                               3074                 :      * Determine vacuum/analyze equation parameters.  We have two possible
                               3075                 :      * sources: the passed reloptions (which could be a main table or a toast
                               3076                 :      * table), or the autovacuum GUC variables.
                               3077                 :      */
                               3078                 : 
                               3079                 :     /* -1 in autovac setting means use plain vacuum_scale_factor */
 4973 alvherre                 3080 GIC          26 :     vac_scale_factor = (relopts && relopts->vacuum_scale_factor >= 0)
 4973 alvherre                 3081 UIC           0 :         ? relopts->vacuum_scale_factor
 4973 alvherre                 3082 GIC        2596 :         : autovacuum_vac_scale;
                               3083                 : 
                               3084              26 :     vac_base_thresh = (relopts && relopts->vacuum_threshold >= 0)
                               3085                 :         ? relopts->vacuum_threshold
                               3086            2596 :         : autovacuum_vac_thresh;
                               3087                 : 
 1107 drowley                  3088              26 :     vac_ins_scale_factor = (relopts && relopts->vacuum_ins_scale_factor >= 0)
 1107 drowley                  3089 UIC           0 :         ? relopts->vacuum_ins_scale_factor
 1107 drowley                  3090 GIC        2596 :         : autovacuum_vac_ins_scale;
                               3091                 : 
                               3092                 :     /* -1 is used to disable insert vacuums */
                               3093              26 :     vac_ins_base_thresh = (relopts && relopts->vacuum_ins_threshold >= -1)
                               3094                 :         ? relopts->vacuum_ins_threshold
                               3095            2596 :         : autovacuum_vac_ins_thresh;
                               3096                 : 
 4973 alvherre                 3097              26 :     anl_scale_factor = (relopts && relopts->analyze_scale_factor >= 0)
 4973 alvherre                 3098 UIC           0 :         ? relopts->analyze_scale_factor
 4973 alvherre                 3099 CBC        2596 :         : autovacuum_anl_scale;
                               3100                 : 
 4973 alvherre                 3101 GIC          26 :     anl_base_thresh = (relopts && relopts->analyze_threshold >= 0)
                               3102                 :         ? relopts->analyze_threshold
                               3103            2596 :         : autovacuum_anl_thresh;
                               3104                 : 
                               3105              26 :     freeze_max_age = (relopts && relopts->freeze_max_age >= 0)
 4973 alvherre                 3106 UIC           0 :         ? Min(relopts->freeze_max_age, autovacuum_freeze_max_age)
 4973 alvherre                 3107 GIC        2596 :         : autovacuum_freeze_max_age;
                               3108                 : 
 3342                          3109              26 :     multixact_freeze_max_age = (relopts && relopts->multixact_freeze_max_age >= 0)
 2893 rhaas                    3110 UIC           0 :         ? Min(relopts->multixact_freeze_max_age, effective_multixact_freeze_max_age)
 2893 rhaas                    3111 GIC        2596 :         : effective_multixact_freeze_max_age;
                               3112                 : 
 4973 alvherre                 3113            2570 :     av_enabled = (relopts ? relopts->enabled : true);
                               3114                 : 
                               3115                 :     /* Force vacuum if table is at risk of wraparound */
 5999 tgl                      3116            2570 :     xidForceLimit = recentXid - freeze_max_age;
                               3117            2570 :     if (xidForceLimit < FirstNormalTransactionId)
 5999 tgl                      3118 UIC           0 :         xidForceLimit -= FirstNormalTransactionId;
 5999 tgl                      3119 GIC        5140 :     force_vacuum = (TransactionIdIsNormal(classForm->relfrozenxid) &&
                               3120            2570 :                     TransactionIdPrecedes(classForm->relfrozenxid,
                               3121                 :                                           xidForceLimit));
 3728 alvherre                 3122            2570 :     if (!force_vacuum)
                               3123                 :     {
 3342                          3124            2570 :         multiForceLimit = recentMulti - multixact_freeze_max_age;
 3728                          3125            2570 :         if (multiForceLimit < FirstMultiXactId)
 3728 alvherre                 3126 UIC           0 :             multiForceLimit -= FirstMultiXactId;
 1447 andres                   3127 GIC        5140 :         force_vacuum = MultiXactIdIsValid(classForm->relminmxid) &&
                               3128            2570 :             MultiXactIdPrecedes(classForm->relminmxid, multiForceLimit);
                               3129                 :     }
 5646 alvherre                 3130            2570 :     *wraparound = force_vacuum;
                               3131                 : 
                               3132                 :     /* User disabled it in pg_class.reloptions?  (But ignore if at risk) */
 3175 tgl                      3133            2570 :     if (!av_enabled && !force_vacuum)
                               3134                 :     {
 5856 alvherre                 3135              20 :         *doanalyze = false;
                               3136              20 :         *dovacuum = false;
 5999 tgl                      3137 CBC          20 :         return;
 5856 alvherre                 3138 ECB             :     }
                               3139                 : 
                               3140                 :     /*
                               3141                 :      * If we found stats for the table, and autovacuum is currently enabled,
                               3142                 :      * make a threshold-based decision whether to vacuum and/or analyze.  If
                               3143                 :      * autovacuum is currently disabled, we must be here for anti-wraparound
                               3144                 :      * vacuuming only, so don't vacuum (or analyze) anything that's not being
                               3145                 :      * forced.
                               3146                 :      */
 3175 tgl                      3147 CBC        2550 :     if (PointerIsValid(tabentry) && AutoVacuumingActive())
 5999 tgl                      3148 EUB             :     {
  730 alvherre                 3149 CBC        1792 :         reltuples = classForm->reltuples;
  124 michael                  3150 GNC        1792 :         vactuples = tabentry->dead_tuples;
                               3151            1792 :         instuples = tabentry->ins_since_vacuum;
                               3152            1792 :         anltuples = tabentry->mod_since_analyze;
 6478 tgl                      3153 ECB             : 
                               3154                 :         /* If the table hasn't yet been vacuumed, take reltuples as zero */
  952 tgl                      3155 CBC        1792 :         if (reltuples < 0)
  952 tgl                      3156 GBC         233 :             reltuples = 0;
  952 tgl                      3157 ECB             : 
 5999 tgl                      3158 GIC        1792 :         vacthresh = (float4) vac_base_thresh + vac_scale_factor * reltuples;
 1107 drowley                  3159            1792 :         vacinsthresh = (float4) vac_ins_base_thresh + vac_ins_scale_factor * reltuples;
 5999 tgl                      3160 CBC        1792 :         anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
                               3161                 : 
 5999 tgl                      3162 ECB             :         /*
                               3163                 :          * Note that we don't need to take special consideration for stat
                               3164                 :          * reset, because if that happens, the last vacuum and analyze counts
 5999 tgl                      3165 EUB             :          * will be reset too.
 5999 tgl                      3166 ECB             :          */
 1107 drowley                  3167 GIC        1792 :         if (vac_ins_base_thresh >= 0)
 1107 drowley                  3168 CBC        1792 :             elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: %.0f (threshold %.0f), anl: %.0f (threshold %.0f)",
                               3169                 :                  NameStr(classForm->relname),
 1107 drowley                  3170 ECB             :                  vactuples, vacthresh, instuples, vacinsthresh, anltuples, anlthresh);
                               3171                 :         else
 1107 drowley                  3172 LBC           0 :             elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: (disabled), anl: %.0f (threshold %.0f)",
 1107 drowley                  3173 EUB             :                  NameStr(classForm->relname),
 1107 drowley                  3174 ECB             :                  vactuples, vacthresh, anltuples, anlthresh);
                               3175                 : 
 5999 tgl                      3176                 :         /* Determine if this table needs vacuum or analyze. */
 1107 drowley                  3177 GBC        3482 :         *dovacuum = force_vacuum || (vactuples > vacthresh) ||
 1060 tgl                      3178 CBC        1690 :             (vac_ins_base_thresh >= 0 && instuples > vacinsthresh);
 5856 alvherre                 3179 GIC        1792 :         *doanalyze = (anltuples > anlthresh);
 5999 tgl                      3180 ECB             :     }
                               3181                 :     else
                               3182                 :     {
                               3183                 :         /*
 5624 bruce                    3184                 :          * Skip a table not found in stat hash, unless we have to force vacuum
 3260 bruce                    3185 EUB             :          * for anti-wrap purposes.  If it's not acted upon, there's no need to
 5624 bruce                    3186 ECB             :          * vacuum it.
 5999 tgl                      3187                 :          */
 5856 alvherre                 3188 GIC         758 :         *dovacuum = force_vacuum;
 5856 alvherre                 3189 CBC         758 :         *doanalyze = false;
                               3190                 :     }
 6450 tgl                      3191 ECB             : 
 2265 peter_e                  3192                 :     /* ANALYZE refuses to work with pg_statistic */
 6450 tgl                      3193 GBC        2550 :     if (relid == StatisticRelationId)
 5856 alvherre                 3194 CBC          16 :         *doanalyze = false;
 6478 tgl                      3195 ECB             : }
                               3196                 : 
                               3197                 : /*
                               3198                 :  * autovacuum_do_vac_analyze
                               3199                 :  *      Vacuum and/or analyze the specified table
                               3200                 :  *
                               3201                 :  * We expect the caller to have switched into a memory context that won't
                               3202                 :  * disappear at transaction commit.
                               3203                 :  */
                               3204                 : static void
 2944 alvherre                 3205 CBC         158 : autovacuum_do_vac_analyze(autovac_table *tab, BufferAccessStrategy bstrategy)
 6478 tgl                      3206 ECB             : {
 2014                          3207                 :     RangeVar   *rangevar;
                               3208                 :     VacuumRelation *rel;
                               3209                 :     List       *rel_list;
                               3210                 :     MemoryContext vac_context;
                               3211                 : 
                               3212                 :     /* Let pgstat know what we're doing */
 5379 alvherre                 3213 GIC         158 :     autovac_report_activity(tab);
                               3214                 : 
                               3215                 :     /* Set up one VacuumRelation target, identified by OID, for vacuum() */
 2014 tgl                      3216             158 :     rangevar = makeRangeVar(tab->at_nspname, tab->at_relname, -1);
                               3217             158 :     rel = makeVacuumRelation(rangevar, tab->at_relid, NIL);
 2014 tgl                      3218 CBC         158 :     rel_list = list_make1(rel);
                               3219                 : 
    3 drowley                  3220 GNC         158 :     vac_context = AllocSetContextCreate(CurrentMemoryContext,
                               3221                 :                                         "Vacuum",
                               3222                 :                                         ALLOCSET_DEFAULT_SIZES);
                               3223                 : 
                               3224             158 :     vacuum(rel_list, &tab->at_params, bstrategy, vac_context, true);
                               3225                 : 
                               3226             158 :     MemoryContextDelete(vac_context);
 6478 tgl                      3227 CBC         158 : }
 6478 tgl                      3228 ECB             : 
 6169 alvherre                 3229                 : /*
                               3230                 :  * autovac_report_activity
                               3231                 :  *      Report to pgstat what autovacuum is doing
                               3232                 :  *
                               3233                 :  * We send a SQL string corresponding to what the user would see if the
                               3234                 :  * equivalent command was to be issued manually.
                               3235                 :  *
                               3236                 :  * Note we assume that we are going to report the next command as soon as we're
 5677 tgl                      3237                 :  * done with the current one, and exit right after the last one, so we don't
                               3238                 :  * bother to report "<IDLE>" or some such.
                               3239                 :  */
                               3240                 : static void
 5379 alvherre                 3241 GIC         158 : autovac_report_activity(autovac_table *tab)
                               3242                 : {
                               3243                 : #define MAX_AUTOVAC_ACTIV_LEN (NAMEDATALEN * 2 + 56)
 5050 bruce                    3244 ECB             :     char        activity[MAX_AUTOVAC_ACTIV_LEN];
                               3245                 :     int         len;
                               3246                 : 
                               3247                 :     /* Report the command and possible options */
 1483 rhaas                    3248 GIC         158 :     if (tab->at_params.options & VACOPT_VACUUM)
 6169 alvherre                 3249 GBC          75 :         snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
                               3250                 :                  "autovacuum: VACUUM%s",
 1483 rhaas                    3251 GIC          75 :                  tab->at_params.options & VACOPT_ANALYZE ? " ANALYZE" : "");
                               3252                 :     else
 6169 alvherre                 3253              83 :         snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
 5564 alvherre                 3254 ECB             :                  "autovacuum: ANALYZE");
 6169                          3255                 : 
 5999 tgl                      3256                 :     /*
                               3257                 :      * Report the qualified name of the relation.
                               3258                 :      */
 5379 alvherre                 3259 GIC         158 :     len = strlen(activity);
                               3260                 : 
                               3261             158 :     snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
                               3262                 :              " %s.%s%s", tab->at_nspname, tab->at_relname,
 2944                          3263             158 :              tab->at_params.is_wraparound ? " (to prevent wraparound)" : "");
                               3264                 : 
 5677 tgl                      3265 ECB             :     /* Set statement_timestamp() to current time for pg_stat_activity */
 5677 tgl                      3266 CBC         158 :     SetCurrentStatementStartTimestamp();
                               3267                 : 
 4098 magnus                   3268 GIC         158 :     pgstat_report_activity(STATE_RUNNING, activity);
 6169 alvherre                 3269             158 : }
 6169 alvherre                 3270 ECB             : 
 2199                          3271                 : /*
                               3272                 :  * autovac_report_workitem
                               3273                 :  *      Report to pgstat that autovacuum is processing a work item
                               3274                 :  */
                               3275                 : static void
 2199 alvherre                 3276 GIC           3 : autovac_report_workitem(AutoVacuumWorkItem *workitem,
                               3277                 :                         const char *nspname, const char *relname)
                               3278                 : {
                               3279                 :     char        activity[MAX_AUTOVAC_ACTIV_LEN + 12 + 2];
                               3280                 :     char        blk[12 + 2];
                               3281                 :     int         len;
 2199 alvherre                 3282 ECB             : 
 2199 alvherre                 3283 GIC           3 :     switch (workitem->avw_type)
                               3284                 :     {
                               3285               3 :         case AVW_BRINSummarizeRange:
                               3286               3 :             snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
                               3287                 :                      "autovacuum: BRIN summarize");
                               3288               3 :             break;
                               3289                 :     }
 2199 alvherre                 3290 ECB             : 
                               3291                 :     /*
                               3292                 :      * Report the qualified name of the relation, and the block number if any
                               3293                 :      */
 2199 alvherre                 3294 CBC           3 :     len = strlen(activity);
 2199 alvherre                 3295 ECB             : 
 2199 alvherre                 3296 GIC           3 :     if (BlockNumberIsValid(workitem->avw_blockNumber))
 2199 alvherre                 3297 CBC           3 :         snprintf(blk, sizeof(blk), " %u", workitem->avw_blockNumber);
                               3298                 :     else
 2199 alvherre                 3299 UIC           0 :         blk[0] = '\0';
                               3300                 : 
 2199 alvherre                 3301 CBC           3 :     snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
                               3302                 :              " %s.%s%s", nspname, relname, blk);
 2199 alvherre                 3303 ECB             : 
                               3304                 :     /* Set statement_timestamp() to current time for pg_stat_activity */
 2199 alvherre                 3305 GIC           3 :     SetCurrentStatementStartTimestamp();
                               3306                 : 
                               3307               3 :     pgstat_report_activity(STATE_RUNNING, activity);
                               3308               3 : }
                               3309                 : 
                               3310                 : /*
                               3311                 :  * AutoVacuumingActive
                               3312                 :  *      Check GUC vars and report whether the autovacuum process should be
                               3313                 :  *      running.
                               3314                 :  */
                               3315                 : bool
 6478 tgl                      3316            6699 : AutoVacuumingActive(void)
                               3317                 : {
 5676 tgl                      3318 CBC        6699 :     if (!autovacuum_start_daemon || !pgstat_track_counts)
 6478 tgl                      3319 GIC        1107 :         return false;
                               3320            5592 :     return true;
                               3321                 : }
                               3322                 : 
                               3323                 : /*
                               3324                 :  * Request one work item to the next autovacuum run processing our database.
 1852 alvherre                 3325 ECB             :  * Return false if the request can't be recorded.
 2199                          3326                 :  */
                               3327                 : bool
 2199 alvherre                 3328 CBC           3 : AutoVacuumRequestWork(AutoVacuumWorkItemType type, Oid relationId,
                               3329                 :                       BlockNumber blkno)
 2199 alvherre                 3330 ECB             : {
                               3331                 :     int         i;
 1852 alvherre                 3332 GIC           3 :     bool        result = false;
                               3333                 : 
 2199                          3334               3 :     LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
                               3335                 : 
 2199 alvherre                 3336 ECB             :     /*
                               3337                 :      * Locate an unused work item and fill it with the given data.
                               3338                 :      */
 2063 alvherre                 3339 GIC           6 :     for (i = 0; i < NUM_WORKITEMS; i++)
 2199 alvherre                 3340 ECB             :     {
 2063 alvherre                 3341 GIC           6 :         AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
                               3342                 : 
 2063 alvherre                 3343 CBC           6 :         if (workitem->avw_used)
 2063 alvherre                 3344 GIC           3 :             continue;
 2199 alvherre                 3345 ECB             : 
 2063 alvherre                 3346 CBC           3 :         workitem->avw_used = true;
 2063 alvherre                 3347 GIC           3 :         workitem->avw_active = false;
                               3348               3 :         workitem->avw_type = type;
                               3349               3 :         workitem->avw_database = MyDatabaseId;
                               3350               3 :         workitem->avw_relation = relationId;
                               3351               3 :         workitem->avw_blockNumber = blkno;
 1852                          3352               3 :         result = true;
 2199 alvherre                 3353 ECB             : 
                               3354                 :         /* done */
 2063 alvherre                 3355 GIC           3 :         break;
                               3356                 :     }
                               3357                 : 
 2199                          3358               3 :     LWLockRelease(AutovacuumLock);
                               3359                 : 
 1852 alvherre                 3360 CBC           3 :     return result;
                               3361                 : }
 2199 alvherre                 3362 ECB             : 
 6478 tgl                      3363                 : /*
                               3364                 :  * autovac_init
 6385 bruce                    3365                 :  *      This is called at postmaster initialization.
                               3366                 :  *
                               3367                 :  * All we do here is annoy the user if he got it wrong.
                               3368                 :  */
                               3369                 : void
 6478 tgl                      3370 GIC         593 : autovac_init(void)
 6478 tgl                      3371 ECB             : {
 5676 tgl                      3372 GIC         593 :     if (autovacuum_start_daemon && !pgstat_track_counts)
 6478 tgl                      3373 LBC           0 :         ereport(WARNING,
 6478 tgl                      3374 ECB             :                 (errmsg("autovacuum not started because of misconfiguration"),
                               3375                 :                  errhint("Enable the \"track_counts\" option.")));
 6478 tgl                      3376 GBC         593 : }
                               3377                 : 
 6478 tgl                      3378 ECB             : /*
                               3379                 :  * IsAutoVacuum functions
                               3380                 :  *      Return whether this is either a launcher autovacuum process or a worker
                               3381                 :  *      process.
                               3382                 :  */
                               3383                 : bool
 5897 alvherre                 3384 CBC       44779 : IsAutoVacuumLauncherProcess(void)
 5897 alvherre                 3385 ECB             : {
 5897 alvherre                 3386 GIC       44779 :     return am_autovacuum_launcher;
                               3387                 : }
                               3388                 : 
                               3389                 : bool
                               3390          232939 : IsAutoVacuumWorkerProcess(void)
                               3391                 : {
                               3392          232939 :     return am_autovacuum_worker;
 5897 alvherre                 3393 ECB             : }
                               3394                 : 
                               3395                 : 
                               3396                 : /*
                               3397                 :  * AutoVacuumShmemSize
                               3398                 :  *      Compute space needed for autovacuum-related shared memory
                               3399                 :  */
                               3400                 : Size
 5897 alvherre                 3401 GIC        4564 : AutoVacuumShmemSize(void)
                               3402                 : {
                               3403                 :     Size        size;
                               3404                 : 
 5837 alvherre                 3405 ECB             :     /*
                               3406                 :      * Need the fixed struct and the array of WorkerInfoData.
                               3407                 :      */
 5837 alvherre                 3408 GIC        4564 :     size = sizeof(AutoVacuumShmemStruct);
 5837 alvherre                 3409 CBC        4564 :     size = MAXALIGN(size);
 5837 alvherre                 3410 GIC        4564 :     size = add_size(size, mul_size(autovacuum_max_workers,
 5837 alvherre                 3411 ECB             :                                    sizeof(WorkerInfoData)));
 5837 alvherre                 3412 GIC        4564 :     return size;
                               3413                 : }
                               3414                 : 
                               3415                 : /*
 5897 alvherre                 3416 ECB             :  * AutoVacuumShmemInit
                               3417                 :  *      Allocate and initialize autovacuum-related shared memory
                               3418                 :  */
                               3419                 : void
 5897 alvherre                 3420 CBC        1826 : AutoVacuumShmemInit(void)
 5897 alvherre                 3421 ECB             : {
                               3422                 :     bool        found;
                               3423                 : 
 5897 alvherre                 3424 CBC        1826 :     AutoVacuumShmem = (AutoVacuumShmemStruct *)
                               3425            1826 :         ShmemInitStruct("AutoVacuum Data",
 5897 alvherre                 3426 ECB             :                         AutoVacuumShmemSize(),
                               3427                 :                         &found);
                               3428                 : 
 5837 alvherre                 3429 CBC        1826 :     if (!IsUnderPostmaster)
                               3430                 :     {
                               3431                 :         WorkerInfo  worker;
 5837 alvherre                 3432 ECB             :         int         i;
                               3433                 : 
 5837 alvherre                 3434 GIC        1826 :         Assert(!found);
 5837 alvherre                 3435 ECB             : 
 5837 alvherre                 3436 GIC        1826 :         AutoVacuumShmem->av_launcherpid = 0;
 3827 alvherre                 3437 CBC        1826 :         dlist_init(&AutoVacuumShmem->av_freeWorkers);
 3827 alvherre                 3438 GIC        1826 :         dlist_init(&AutoVacuumShmem->av_runningWorkers);
 5271 tgl                      3439            1826 :         AutoVacuumShmem->av_startingWorker = NULL;
 2063 alvherre                 3440            1826 :         memset(AutoVacuumShmem->av_workItems, 0,
                               3441                 :                sizeof(AutoVacuumWorkItem) * NUM_WORKITEMS);
                               3442                 : 
 5837                          3443            1826 :         worker = (WorkerInfo) ((char *) AutoVacuumShmem +
                               3444                 :                                MAXALIGN(sizeof(AutoVacuumShmemStruct)));
                               3445                 : 
                               3446                 :         /* initialize the WorkerInfo free list */
 5837 alvherre                 3447 CBC        7304 :         for (i = 0; i < autovacuum_max_workers; i++)
                               3448                 :         {
 3825 tgl                      3449 GIC        5478 :             dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
 3825 tgl                      3450 CBC        5478 :                             &worker[i].wi_links);
    2 dgustafsson              3451 GNC        5478 :             pg_atomic_init_flag(&worker[i].wi_dobalance);
                               3452                 :         }
                               3453                 : 
                               3454            1826 :         pg_atomic_init_u32(&AutoVacuumShmem->av_nworkersForBalance, 0);
                               3455                 : 
 5837 alvherre                 3456 EUB             :     }
                               3457                 :     else
 5837 alvherre                 3458 UIC           0 :         Assert(found);
 6478 tgl                      3459 CBC        1826 : }
                               3460                 : 
                               3461                 : /*
                               3462                 :  * GUC check_hook for autovacuum_work_mem
                               3463                 :  */
                               3464                 : bool
  208 tgl                      3465 GNC        1859 : check_autovacuum_work_mem(int *newval, void **extra, GucSource source)
                               3466                 : {
                               3467                 :     /*
                               3468                 :      * -1 indicates fallback.
                               3469                 :      *
                               3470                 :      * If we haven't yet changed the boot_val default of -1, just let it be.
                               3471                 :      * Autovacuum will look to maintenance_work_mem instead.
                               3472                 :      */
                               3473            1859 :     if (*newval == -1)
                               3474            1857 :         return true;
                               3475                 : 
                               3476                 :     /*
                               3477                 :      * We clamp manually-set values to at least 1MB.  Since
                               3478                 :      * maintenance_work_mem is always set to at least this value, do the same
                               3479                 :      * here.
                               3480                 :      */
                               3481               2 :     if (*newval < 1024)
                               3482               2 :         *newval = 1024;
                               3483                 : 
                               3484               2 :     return true;
                               3485                 : }
        

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