LCOV - differential code coverage report
Current view: top level - src/backend/utils/mmgr - aset.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: 89.2 % 390 348 9 4 28 1 13 155 117 63 27 225 1 56
Current Date: 2023-04-08 15:15:32 Functions: 100.0 % 12 12 8 4 9 3
Baseline: 15
Baseline Date: 2023-04-08 15:09:40
Legend: Lines: hit not hit

           TLA  Line data    Source code
       1                 : /*-------------------------------------------------------------------------
       2                 :  *
       3                 :  * aset.c
       4                 :  *    Allocation set definitions.
       5                 :  *
       6                 :  * AllocSet is our standard implementation of the abstract MemoryContext
       7                 :  * type.
       8                 :  *
       9                 :  *
      10                 :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
      11                 :  * Portions Copyright (c) 1994, Regents of the University of California
      12                 :  *
      13                 :  * IDENTIFICATION
      14                 :  *    src/backend/utils/mmgr/aset.c
      15                 :  *
      16                 :  * NOTE:
      17                 :  *  This is a new (Feb. 05, 1999) implementation of the allocation set
      18                 :  *  routines. AllocSet...() does not use OrderedSet...() any more.
      19                 :  *  Instead it manages allocations in a block pool by itself, combining
      20                 :  *  many small allocations in a few bigger blocks. AllocSetFree() normally
      21                 :  *  doesn't free() memory really. It just add's the free'd area to some
      22                 :  *  list for later reuse by AllocSetAlloc(). All memory blocks are free()'d
      23                 :  *  at once on AllocSetReset(), which happens when the memory context gets
      24                 :  *  destroyed.
      25                 :  *              Jan Wieck
      26                 :  *
      27                 :  *  Performance improvement from Tom Lane, 8/99: for extremely large request
      28                 :  *  sizes, we do want to be able to give the memory back to free() as soon
      29                 :  *  as it is pfree()'d.  Otherwise we risk tying up a lot of memory in
      30                 :  *  freelist entries that might never be usable.  This is specially needed
      31                 :  *  when the caller is repeatedly repalloc()'ing a block bigger and bigger;
      32                 :  *  the previous instances of the block were guaranteed to be wasted until
      33                 :  *  AllocSetReset() under the old way.
      34                 :  *
      35                 :  *  Further improvement 12/00: as the code stood, request sizes in the
      36                 :  *  midrange between "small" and "large" were handled very inefficiently,
      37                 :  *  because any sufficiently large free chunk would be used to satisfy a
      38                 :  *  request, even if it was much larger than necessary.  This led to more
      39                 :  *  and more wasted space in allocated chunks over time.  To fix, get rid
      40                 :  *  of the midrange behavior: we now handle only "small" power-of-2-size
      41                 :  *  chunks as chunks.  Anything "large" is passed off to malloc().  Change
      42                 :  *  the number of freelists to change the small/large boundary.
      43                 :  *
      44                 :  *-------------------------------------------------------------------------
      45                 :  */
      46                 : 
      47                 : #include "postgres.h"
      48                 : 
      49                 : #include "port/pg_bitutils.h"
      50                 : #include "utils/memdebug.h"
      51                 : #include "utils/memutils.h"
      52                 : #include "utils/memutils_memorychunk.h"
      53                 : #include "utils/memutils_internal.h"
      54                 : 
      55                 : /*--------------------
      56                 :  * Chunk freelist k holds chunks of size 1 << (k + ALLOC_MINBITS),
      57                 :  * for k = 0 .. ALLOCSET_NUM_FREELISTS-1.
      58                 :  *
      59                 :  * Note that all chunks in the freelists have power-of-2 sizes.  This
      60                 :  * improves recyclability: we may waste some space, but the wasted space
      61                 :  * should stay pretty constant as requests are made and released.
      62                 :  *
      63                 :  * A request too large for the last freelist is handled by allocating a
      64                 :  * dedicated block from malloc().  The block still has a block header and
      65                 :  * chunk header, but when the chunk is freed we'll return the whole block
      66                 :  * to malloc(), not put it on our freelists.
      67                 :  *
      68                 :  * CAUTION: ALLOC_MINBITS must be large enough so that
      69                 :  * 1<<ALLOC_MINBITS is at least MAXALIGN,
      70                 :  * or we may fail to align the smallest chunks adequately.
      71                 :  * 8-byte alignment is enough on all currently known machines.  This 8-byte
      72                 :  * minimum also allows us to store a pointer to the next freelist item within
      73                 :  * the chunk of memory itself.
      74                 :  *
      75                 :  * With the current parameters, request sizes up to 8K are treated as chunks,
      76                 :  * larger requests go into dedicated blocks.  Change ALLOCSET_NUM_FREELISTS
      77                 :  * to adjust the boundary point; and adjust ALLOCSET_SEPARATE_THRESHOLD in
      78                 :  * memutils.h to agree.  (Note: in contexts with small maxBlockSize, we may
      79                 :  * set the allocChunkLimit to less than 8K, so as to avoid space wastage.)
      80                 :  *--------------------
      81                 :  */
      82                 : 
      83                 : #define ALLOC_MINBITS       3   /* smallest chunk size is 8 bytes */
      84                 : #define ALLOCSET_NUM_FREELISTS  11
      85                 : #define ALLOC_CHUNK_LIMIT   (1 << (ALLOCSET_NUM_FREELISTS-1+ALLOC_MINBITS))
      86                 : /* Size of largest chunk that we use a fixed size for */
      87                 : #define ALLOC_CHUNK_FRACTION    4
      88                 : /* We allow chunks to be at most 1/4 of maxBlockSize (less overhead) */
      89                 : 
      90                 : /*--------------------
      91                 :  * The first block allocated for an allocset has size initBlockSize.
      92                 :  * Each time we have to allocate another block, we double the block size
      93                 :  * (if possible, and without exceeding maxBlockSize), so as to reduce
      94                 :  * the bookkeeping load on malloc().
      95                 :  *
      96                 :  * Blocks allocated to hold oversize chunks do not follow this rule, however;
      97                 :  * they are just however big they need to be to hold that single chunk.
      98                 :  *
      99                 :  * Also, if a minContextSize is specified, the first block has that size,
     100                 :  * and then initBlockSize is used for the next one.
     101                 :  *--------------------
     102                 :  */
     103                 : 
     104                 : #define ALLOC_BLOCKHDRSZ    MAXALIGN(sizeof(AllocBlockData))
     105                 : #define ALLOC_CHUNKHDRSZ    sizeof(MemoryChunk)
     106                 : 
     107                 : typedef struct AllocBlockData *AllocBlock;  /* forward reference */
     108                 : 
     109                 : /*
     110                 :  * AllocPointer
     111                 :  *      Aligned pointer which may be a member of an allocation set.
     112                 :  */
     113                 : typedef void *AllocPointer;
     114                 : 
     115                 : /*
     116                 :  * AllocFreeListLink
     117                 :  *      When pfreeing memory, if we maintain a freelist for the given chunk's
     118                 :  *      size then we use a AllocFreeListLink to point to the current item in
     119                 :  *      the AllocSetContext's freelist and then set the given freelist element
     120                 :  *      to point to the chunk being freed.
     121                 :  */
     122                 : typedef struct AllocFreeListLink
     123                 : {
     124                 :     MemoryChunk *next;
     125                 : } AllocFreeListLink;
     126                 : 
     127                 : /*
     128                 :  * Obtain a AllocFreeListLink for the given chunk.  Allocation sizes are
     129                 :  * always at least sizeof(AllocFreeListLink), so we reuse the pointer's memory
     130                 :  * itself to store the freelist link.
     131                 :  */
     132                 : #define GetFreeListLink(chkptr) \
     133                 :     (AllocFreeListLink *) ((char *) (chkptr) + ALLOC_CHUNKHDRSZ)
     134                 : 
     135                 : /* Validate a freelist index retrieved from a chunk header */
     136                 : #define FreeListIdxIsValid(fidx) \
     137                 :     ((fidx) >= 0 && (fidx) < ALLOCSET_NUM_FREELISTS)
     138                 : 
     139                 : /* Determine the size of the chunk based on the freelist index */
     140                 : #define GetChunkSizeFromFreeListIdx(fidx) \
     141                 :     ((((Size) 1) << ALLOC_MINBITS) << (fidx))
     142                 : 
     143                 : /*
     144                 :  * AllocSetContext is our standard implementation of MemoryContext.
     145                 :  *
     146                 :  * Note: header.isReset means there is nothing for AllocSetReset to do.
     147                 :  * This is different from the aset being physically empty (empty blocks list)
     148                 :  * because we will still have a keeper block.  It's also different from the set
     149                 :  * being logically empty, because we don't attempt to detect pfree'ing the
     150                 :  * last active chunk.
     151                 :  */
     152                 : typedef struct AllocSetContext
     153                 : {
     154                 :     MemoryContextData header;   /* Standard memory-context fields */
     155                 :     /* Info about storage allocated in this context: */
     156                 :     AllocBlock  blocks;         /* head of list of blocks in this set */
     157                 :     MemoryChunk *freelist[ALLOCSET_NUM_FREELISTS];  /* free chunk lists */
     158                 :     /* Allocation parameters for this context: */
     159                 :     Size        initBlockSize;  /* initial block size */
     160                 :     Size        maxBlockSize;   /* maximum block size */
     161                 :     Size        nextBlockSize;  /* next block size to allocate */
     162                 :     Size        allocChunkLimit;    /* effective chunk size limit */
     163                 :     AllocBlock  keeper;         /* keep this block over resets */
     164                 :     /* freelist this context could be put in, or -1 if not a candidate: */
     165                 :     int         freeListIndex;  /* index in context_freelists[], or -1 */
     166                 : } AllocSetContext;
     167                 : 
     168                 : typedef AllocSetContext *AllocSet;
     169                 : 
     170                 : /*
     171                 :  * AllocBlock
     172                 :  *      An AllocBlock is the unit of memory that is obtained by aset.c
     173                 :  *      from malloc().  It contains one or more MemoryChunks, which are
     174                 :  *      the units requested by palloc() and freed by pfree(). MemoryChunks
     175                 :  *      cannot be returned to malloc() individually, instead they are put
     176                 :  *      on freelists by pfree() and re-used by the next palloc() that has
     177                 :  *      a matching request size.
     178                 :  *
     179                 :  *      AllocBlockData is the header data for a block --- the usable space
     180                 :  *      within the block begins at the next alignment boundary.
     181                 :  */
     182                 : typedef struct AllocBlockData
     183                 : {
     184                 :     AllocSet    aset;           /* aset that owns this block */
     185                 :     AllocBlock  prev;           /* prev block in aset's blocks list, if any */
     186                 :     AllocBlock  next;           /* next block in aset's blocks list, if any */
     187                 :     char       *freeptr;        /* start of free space in this block */
     188                 :     char       *endptr;         /* end of space in this block */
     189                 : }           AllocBlockData;
     190                 : 
     191                 : /*
     192                 :  * Only the "hdrmask" field should be accessed outside this module.
     193                 :  * We keep the rest of an allocated chunk's header marked NOACCESS when using
     194                 :  * valgrind.  But note that chunk headers that are in a freelist are kept
     195                 :  * accessible, for simplicity.
     196                 :  */
     197                 : #define ALLOCCHUNK_PRIVATE_LEN  offsetof(MemoryChunk, hdrmask)
     198                 : 
     199                 : /*
     200                 :  * AllocPointerIsValid
     201                 :  *      True iff pointer is valid allocation pointer.
     202                 :  */
     203                 : #define AllocPointerIsValid(pointer) PointerIsValid(pointer)
     204                 : 
     205                 : /*
     206                 :  * AllocSetIsValid
     207                 :  *      True iff set is valid allocation set.
     208                 :  */
     209                 : #define AllocSetIsValid(set) \
     210                 :     (PointerIsValid(set) && IsA(set, AllocSetContext))
     211                 : 
     212                 : /*
     213                 :  * AllocBlockIsValid
     214                 :  *      True iff block is valid block of allocation set.
     215                 :  */
     216                 : #define AllocBlockIsValid(block) \
     217                 :     (PointerIsValid(block) && AllocSetIsValid((block)->aset))
     218                 : 
     219                 : /*
     220                 :  * We always store external chunks on a dedicated block.  This makes fetching
     221                 :  * the block from an external chunk easy since it's always the first and only
     222                 :  * chunk on the block.
     223                 :  */
     224                 : #define ExternalChunkGetBlock(chunk) \
     225                 :     (AllocBlock) ((char *) chunk - ALLOC_BLOCKHDRSZ)
     226                 : 
     227                 : /*
     228                 :  * Rather than repeatedly creating and deleting memory contexts, we keep some
     229                 :  * freed contexts in freelists so that we can hand them out again with little
     230                 :  * work.  Before putting a context in a freelist, we reset it so that it has
     231                 :  * only its initial malloc chunk and no others.  To be a candidate for a
     232                 :  * freelist, a context must have the same minContextSize/initBlockSize as
     233                 :  * other contexts in the list; but its maxBlockSize is irrelevant since that
     234                 :  * doesn't affect the size of the initial chunk.
     235                 :  *
     236                 :  * We currently provide one freelist for ALLOCSET_DEFAULT_SIZES contexts
     237                 :  * and one for ALLOCSET_SMALL_SIZES contexts; the latter works for
     238                 :  * ALLOCSET_START_SMALL_SIZES too, since only the maxBlockSize differs.
     239                 :  *
     240                 :  * Ordinarily, we re-use freelist contexts in last-in-first-out order, in
     241                 :  * hopes of improving locality of reference.  But if there get to be too
     242                 :  * many contexts in the list, we'd prefer to drop the most-recently-created
     243                 :  * contexts in hopes of keeping the process memory map compact.
     244                 :  * We approximate that by simply deleting all existing entries when the list
     245                 :  * overflows, on the assumption that queries that allocate a lot of contexts
     246                 :  * will probably free them in more or less reverse order of allocation.
     247                 :  *
     248                 :  * Contexts in a freelist are chained via their nextchild pointers.
     249                 :  */
     250                 : #define MAX_FREE_CONTEXTS 100   /* arbitrary limit on freelist length */
     251                 : 
     252                 : typedef struct AllocSetFreeList
     253                 : {
     254                 :     int         num_free;       /* current list length */
     255                 :     AllocSetContext *first_free;    /* list header */
     256                 : } AllocSetFreeList;
     257                 : 
     258                 : /* context_freelists[0] is for default params, [1] for small params */
     259                 : static AllocSetFreeList context_freelists[2] =
     260                 : {
     261                 :     {
     262                 :         0, NULL
     263                 :     },
     264                 :     {
     265                 :         0, NULL
     266                 :     }
     267                 : };
     268                 : 
     269                 : 
     270                 : /* ----------
     271                 :  * AllocSetFreeIndex -
     272                 :  *
     273 ECB             :  *      Depending on the size of an allocation compute which freechunk
     274                 :  *      list of the alloc set it belongs to.  Caller must have verified
     275                 :  *      that size <= ALLOC_CHUNK_LIMIT.
     276                 :  * ----------
     277                 :  */
     278                 : static inline int
     279 GIC   620371798 : AllocSetFreeIndex(Size size)
     280                 : {
     281                 :     int         idx;
     282                 : 
     283       620371798 :     if (size > (1 << ALLOC_MINBITS))
     284                 :     {
     285                 :         /*----------
     286                 :          * At this point we must compute ceil(log2(size >> ALLOC_MINBITS)).
     287                 :          * This is the same as
     288 ECB             :          *      pg_leftmost_one_pos32((size - 1) >> ALLOC_MINBITS) + 1
     289                 :          * or equivalently
     290                 :          *      pg_leftmost_one_pos32(size - 1) - ALLOC_MINBITS + 1
     291                 :          *
     292                 :          * However, for platforms without intrinsic support, we duplicate the
     293                 :          * logic here, allowing an additional optimization.  It's reasonable
     294                 :          * to assume that ALLOC_CHUNK_LIMIT fits in 16 bits, so we can unroll
     295                 :          * the byte-at-a-time loop in pg_leftmost_one_pos32 and just handle
     296                 :          * the last two bytes.
     297                 :          *
     298                 :          * Yes, this function is enough of a hot-spot to make it worth this
     299                 :          * much trouble.
     300                 :          *----------
     301                 :          */
     302                 : #ifdef HAVE_BITSCAN_REVERSE
     303 GNC   524971614 :         idx = pg_leftmost_one_pos32((uint32) size - 1) - ALLOC_MINBITS + 1;
     304                 : #else
     305                 :         uint32      t,
     306                 :                     tsize;
     307                 : 
     308                 :         /* Statically assert that we only have a 16-bit input value. */
     309                 :         StaticAssertDecl(ALLOC_CHUNK_LIMIT < (1 << 16),
     310                 :                          "ALLOC_CHUNK_LIMIT must be less than 64kB");
     311                 : 
     312                 :         tsize = size - 1;
     313                 :         t = tsize >> 8;
     314                 :         idx = t ? pg_leftmost_one_pos[t] + 8 : pg_leftmost_one_pos[tsize];
     315                 :         idx -= ALLOC_MINBITS - 1;
     316                 : #endif
     317                 : 
     318 GIC   524971614 :         Assert(idx < ALLOCSET_NUM_FREELISTS);
     319 ECB             :     }
     320                 :     else
     321 GIC    95400184 :         idx = 0;
     322                 : 
     323       620371798 :     return idx;
     324                 : }
     325                 : 
     326                 : 
     327                 : /*
     328                 :  * Public routines
     329                 :  */
     330                 : 
     331                 : 
     332                 : /*
     333                 :  * AllocSetContextCreateInternal
     334                 :  *      Create a new AllocSet context.
     335                 :  *
     336                 :  * parent: parent context, or NULL if top-level context
     337                 :  * name: name of context (must be statically allocated)
     338                 :  * minContextSize: minimum context size
     339                 :  * initBlockSize: initial allocation block size
     340                 :  * maxBlockSize: maximum allocation block size
     341                 :  *
     342                 :  * Most callers should abstract the context size parameters using a macro
     343                 :  * such as ALLOCSET_DEFAULT_SIZES.
     344                 :  *
     345                 :  * Note: don't call this directly; go through the wrapper macro
     346                 :  * AllocSetContextCreate.
     347                 :  */
     348                 : MemoryContext
     349 CBC     6085595 : AllocSetContextCreateInternal(MemoryContext parent,
     350                 :                               const char *name,
     351 ECB             :                               Size minContextSize,
     352                 :                               Size initBlockSize,
     353                 :                               Size maxBlockSize)
     354                 : {
     355                 :     int         freeListIndex;
     356                 :     Size        firstBlockSize;
     357                 :     AllocSet    set;
     358                 :     AllocBlock  block;
     359                 : 
     360                 :     /* ensure MemoryChunk's size is properly maxaligned */
     361                 :     StaticAssertDecl(ALLOC_CHUNKHDRSZ == MAXALIGN(ALLOC_CHUNKHDRSZ),
     362                 :                      "sizeof(MemoryChunk) is not maxaligned");
     363                 :     /* check we have enough space to store the freelist link */
     364                 :     StaticAssertDecl(sizeof(AllocFreeListLink) <= (1 << ALLOC_MINBITS),
     365                 :                      "sizeof(AllocFreeListLink) larger than minimum allocation size");
     366                 : 
     367                 :     /*
     368                 :      * First, validate allocation parameters.  Once these were regular runtime
     369                 :      * tests and elog's, but in practice Asserts seem sufficient because
     370                 :      * nobody varies their parameters at runtime.  We somewhat arbitrarily
     371                 :      * enforce a minimum 1K block size.  We restrict the maximum block size to
     372                 :      * MEMORYCHUNK_MAX_BLOCKOFFSET as MemoryChunks are limited to this in
     373                 :      * regards to addressing the offset between the chunk and the block that
     374                 :      * the chunk is stored on.  We would be unable to store the offset between
     375                 :      * the chunk and block for any chunks that were beyond
     376                 :      * MEMORYCHUNK_MAX_BLOCKOFFSET bytes into the block if the block was to be
     377                 :      * larger than this.
     378                 :      */
     379 GIC     6085595 :     Assert(initBlockSize == MAXALIGN(initBlockSize) &&
     380                 :            initBlockSize >= 1024);
     381         6085595 :     Assert(maxBlockSize == MAXALIGN(maxBlockSize) &&
     382 ECB             :            maxBlockSize >= initBlockSize &&
     383                 :            AllocHugeSizeIsValid(maxBlockSize)); /* must be safe to double */
     384 CBC     6085595 :     Assert(minContextSize == 0 ||
     385                 :            (minContextSize == MAXALIGN(minContextSize) &&
     386 ECB             :             minContextSize >= 1024 &&
     387                 :             minContextSize <= maxBlockSize));
     388 GNC     6085595 :     Assert(maxBlockSize <= MEMORYCHUNK_MAX_BLOCKOFFSET);
     389                 : 
     390 ECB             :     /*
     391                 :      * Check whether the parameters match either available freelist.  We do
     392                 :      * not need to demand a match of maxBlockSize.
     393                 :      */
     394 GIC     6085595 :     if (minContextSize == ALLOCSET_DEFAULT_MINSIZE &&
     395 ECB             :         initBlockSize == ALLOCSET_DEFAULT_INITSIZE)
     396 GIC     4188547 :         freeListIndex = 0;
     397         1897048 :     else if (minContextSize == ALLOCSET_SMALL_MINSIZE &&
     398 ECB             :              initBlockSize == ALLOCSET_SMALL_INITSIZE)
     399 GIC     1882848 :         freeListIndex = 1;
     400                 :     else
     401           14200 :         freeListIndex = -1;
     402                 : 
     403                 :     /*
     404 ECB             :      * If a suitable freelist entry exists, just recycle that context.
     405                 :      */
     406 GIC     6085595 :     if (freeListIndex >= 0)
     407 ECB             :     {
     408 GIC     6071395 :         AllocSetFreeList *freelist = &context_freelists[freeListIndex];
     409                 : 
     410         6071395 :         if (freelist->first_free != NULL)
     411                 :         {
     412 ECB             :             /* Remove entry from freelist */
     413 GIC     4727402 :             set = freelist->first_free;
     414 CBC     4727402 :             freelist->first_free = (AllocSet) set->header.nextchild;
     415         4727402 :             freelist->num_free--;
     416                 : 
     417 ECB             :             /* Update its maxBlockSize; everything else should be OK */
     418 GIC     4727402 :             set->maxBlockSize = maxBlockSize;
     419                 : 
     420                 :             /* Reinitialize its header, installing correct name and parent */
     421         4727402 :             MemoryContextCreate((MemoryContext) set,
     422                 :                                 T_AllocSetContext,
     423                 :                                 MCTX_ASET_ID,
     424 ECB             :                                 parent,
     425                 :                                 name);
     426 EUB             : 
     427 GBC     4727402 :             ((MemoryContext) set)->mem_allocated =
     428         4727402 :                 set->keeper->endptr - ((char *) set);
     429                 : 
     430 GIC     4727402 :             return (MemoryContext) set;
     431                 :         }
     432                 :     }
     433                 : 
     434                 :     /* Determine size of initial block */
     435         1358193 :     firstBlockSize = MAXALIGN(sizeof(AllocSetContext)) +
     436                 :         ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
     437         1358193 :     if (minContextSize != 0)
     438           14200 :         firstBlockSize = Max(firstBlockSize, minContextSize);
     439                 :     else
     440         1343993 :         firstBlockSize = Max(firstBlockSize, initBlockSize);
     441 ECB             : 
     442                 :     /*
     443                 :      * Allocate the initial block.  Unlike other aset.c blocks, it starts with
     444                 :      * the context header and its block header follows that.
     445                 :      */
     446 CBC     1358193 :     set = (AllocSet) malloc(firstBlockSize);
     447 GIC     1358193 :     if (set == NULL)
     448                 :     {
     449 UIC           0 :         if (TopMemoryContext)
     450               0 :             MemoryContextStats(TopMemoryContext);
     451               0 :         ereport(ERROR,
     452 ECB             :                 (errcode(ERRCODE_OUT_OF_MEMORY),
     453                 :                  errmsg("out of memory"),
     454                 :                  errdetail("Failed while creating memory context \"%s\".",
     455                 :                            name)));
     456                 :     }
     457                 : 
     458                 :     /*
     459                 :      * Avoid writing code that can fail between here and MemoryContextCreate;
     460                 :      * we'd leak the header/initial block if we ereport in this stretch.
     461                 :      */
     462                 : 
     463                 :     /* Fill in the initial block's block header */
     464 GIC     1358193 :     block = (AllocBlock) (((char *) set) + MAXALIGN(sizeof(AllocSetContext)));
     465         1358193 :     block->aset = set;
     466         1358193 :     block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
     467         1358193 :     block->endptr = ((char *) set) + firstBlockSize;
     468         1358193 :     block->prev = NULL;
     469         1358193 :     block->next = NULL;
     470                 : 
     471                 :     /* Mark unallocated space NOACCESS; leave the block header alone. */
     472                 :     VALGRIND_MAKE_MEM_NOACCESS(block->freeptr, block->endptr - block->freeptr);
     473                 : 
     474                 :     /* Remember block as part of block list */
     475         1358193 :     set->blocks = block;
     476                 :     /* Mark block as not to be released at reset time */
     477         1358193 :     set->keeper = block;
     478                 : 
     479                 :     /* Finish filling in aset-specific parts of the context header */
     480        16298316 :     MemSetAligned(set->freelist, 0, sizeof(set->freelist));
     481                 : 
     482         1358193 :     set->initBlockSize = initBlockSize;
     483         1358193 :     set->maxBlockSize = maxBlockSize;
     484         1358193 :     set->nextBlockSize = initBlockSize;
     485         1358193 :     set->freeListIndex = freeListIndex;
     486                 : 
     487                 :     /*
     488 ECB             :      * Compute the allocation chunk size limit for this context.  It can't be
     489                 :      * more than ALLOC_CHUNK_LIMIT because of the fixed number of freelists.
     490                 :      * If maxBlockSize is small then requests exceeding the maxBlockSize, or
     491                 :      * even a significant fraction of it, should be treated as large chunks
     492                 :      * too.  For the typical case of maxBlockSize a power of 2, the chunk size
     493                 :      * limit will be at most 1/8th maxBlockSize, so that given a stream of
     494                 :      * requests that are all the maximum chunk size we will waste at most
     495                 :      * 1/8th of the allocated space.
     496                 :      *
     497                 :      * Also, allocChunkLimit must not exceed ALLOCSET_SEPARATE_THRESHOLD.
     498                 :      */
     499                 :     StaticAssertStmt(ALLOC_CHUNK_LIMIT == ALLOCSET_SEPARATE_THRESHOLD,
     500                 :                      "ALLOC_CHUNK_LIMIT != ALLOCSET_SEPARATE_THRESHOLD");
     501                 : 
     502                 :     /*
     503                 :      * Determine the maximum size that a chunk can be before we allocate an
     504                 :      * entire AllocBlock dedicated for that chunk.  We set the absolute limit
     505                 :      * of that size as ALLOC_CHUNK_LIMIT but we reduce it further so that we
     506                 :      * can fit about ALLOC_CHUNK_FRACTION chunks this size on a maximally
     507                 :      * sized block.  (We opt to keep allocChunkLimit a power-of-2 value
     508                 :      * primarily for legacy reasons rather than calculating it so that exactly
     509                 :      * ALLOC_CHUNK_FRACTION chunks fit on a maximally sized block.)
     510                 :      */
     511 GIC     1358193 :     set->allocChunkLimit = ALLOC_CHUNK_LIMIT;
     512         1358193 :     while ((Size) (set->allocChunkLimit + ALLOC_CHUNKHDRSZ) >
     513         4492360 :            (Size) ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
     514         3134167 :         set->allocChunkLimit >>= 1;
     515                 : 
     516                 :     /* Finally, do the type-independent part of context creation */
     517         1358193 :     MemoryContextCreate((MemoryContext) set,
     518                 :                         T_AllocSetContext,
     519                 :                         MCTX_ASET_ID,
     520                 :                         parent,
     521                 :                         name);
     522                 : 
     523 CBC     1358193 :     ((MemoryContext) set)->mem_allocated = firstBlockSize;
     524                 : 
     525         1358193 :     return (MemoryContext) set;
     526                 : }
     527                 : 
     528                 : /*
     529 ECB             :  * AllocSetReset
     530                 :  *      Frees all memory which is allocated in the given set.
     531                 :  *
     532                 :  * Actually, this routine has some discretion about what to do.
     533                 :  * It should mark all allocated chunks freed, but it need not necessarily
     534                 :  * give back all the resources the set owns.  Our actual implementation is
     535                 :  * that we give back all but the "keeper" block (which we must keep, since
     536                 :  * it shares a malloc chunk with the context header).  In this way, we don't
     537                 :  * thrash malloc() when a context is repeatedly reset after small allocations,
     538                 :  * which is typical behavior for per-tuple contexts.
     539                 :  */
     540                 : void
     541 GIC    25269729 : AllocSetReset(MemoryContext context)
     542 ECB             : {
     543 GIC    25269729 :     AllocSet    set = (AllocSet) context;
     544                 :     AllocBlock  block;
     545                 :     Size        keepersize PG_USED_FOR_ASSERTS_ONLY;
     546 ECB             : 
     547 GNC    25269729 :     Assert(AllocSetIsValid(set));
     548 ECB             : 
     549                 : #ifdef MEMORY_CONTEXT_CHECKING
     550                 :     /* Check for corruption and leaks before freeing */
     551 GIC    25269729 :     AllocSetCheck(context);
     552                 : #endif
     553 ECB             : 
     554                 :     /* Remember keeper block size for Assert below */
     555 GNC    25269729 :     keepersize = set->keeper->endptr - ((char *) set);
     556                 : 
     557                 :     /* Clear chunk freelists */
     558 GIC   303236748 :     MemSetAligned(set->freelist, 0, sizeof(set->freelist));
     559 ECB             : 
     560 GIC    25269729 :     block = set->blocks;
     561                 : 
     562                 :     /* New blocks list will be just the keeper block */
     563        25269729 :     set->blocks = set->keeper;
     564 ECB             : 
     565 CBC    54425203 :     while (block != NULL)
     566 ECB             :     {
     567 GIC    29155474 :         AllocBlock  next = block->next;
     568                 : 
     569        29155474 :         if (block == set->keeper)
     570                 :         {
     571 ECB             :             /* Reset the block, but don't return it to malloc */
     572 GIC    25269729 :             char       *datastart = ((char *) block) + ALLOC_BLOCKHDRSZ;
     573                 : 
     574 ECB             : #ifdef CLOBBER_FREED_MEMORY
     575 GIC    25269729 :             wipe_mem(datastart, block->freeptr - datastart);
     576 ECB             : #else
     577                 :             /* wipe_mem() would have done this */
     578                 :             VALGRIND_MAKE_MEM_NOACCESS(datastart, block->freeptr - datastart);
     579                 : #endif
     580 GIC    25269729 :             block->freeptr = datastart;
     581 CBC    25269729 :             block->prev = NULL;
     582 GIC    25269729 :             block->next = NULL;
     583                 :         }
     584 ECB             :         else
     585                 :         {
     586                 :             /* Normal case, release the block */
     587 GIC     3885745 :             context->mem_allocated -= block->endptr - ((char *) block);
     588                 : 
     589                 : #ifdef CLOBBER_FREED_MEMORY
     590         3885745 :             wipe_mem(block, block->freeptr - ((char *) block));
     591                 : #endif
     592         3885745 :             free(block);
     593                 :         }
     594        29155474 :         block = next;
     595 ECB             :     }
     596                 : 
     597 CBC    25269729 :     Assert(context->mem_allocated == keepersize);
     598 ECB             : 
     599                 :     /* Reset block size allocation sequence, too */
     600 GIC    25269729 :     set->nextBlockSize = set->initBlockSize;
     601 CBC    25269729 : }
     602                 : 
     603                 : /*
     604                 :  * AllocSetDelete
     605 ECB             :  *      Frees all memory which is allocated in the given set,
     606                 :  *      in preparation for deletion of the set.
     607                 :  *
     608                 :  * Unlike AllocSetReset, this *must* free all resources of the set.
     609                 :  */
     610                 : void
     611 GIC     4943417 : AllocSetDelete(MemoryContext context)
     612                 : {
     613         4943417 :     AllocSet    set = (AllocSet) context;
     614         4943417 :     AllocBlock  block = set->blocks;
     615                 :     Size        keepersize PG_USED_FOR_ASSERTS_ONLY;
     616 ECB             : 
     617 GNC     4943417 :     Assert(AllocSetIsValid(set));
     618                 : 
     619                 : #ifdef MEMORY_CONTEXT_CHECKING
     620                 :     /* Check for corruption and leaks before freeing */
     621 GIC     4943417 :     AllocSetCheck(context);
     622 ECB             : #endif
     623                 : 
     624                 :     /* Remember keeper block size for Assert below */
     625 GNC     4943417 :     keepersize = set->keeper->endptr - ((char *) set);
     626                 : 
     627                 :     /*
     628                 :      * If the context is a candidate for a freelist, put it into that freelist
     629                 :      * instead of destroying it.
     630                 :      */
     631 GIC     4943417 :     if (set->freeListIndex >= 0)
     632 ECB             :     {
     633 GIC     4943417 :         AllocSetFreeList *freelist = &context_freelists[set->freeListIndex];
     634 ECB             : 
     635                 :         /*
     636                 :          * Reset the context, if it needs it, so that we aren't hanging on to
     637                 :          * more than the initial malloc chunk.
     638                 :          */
     639 CBC     4943417 :         if (!context->isReset)
     640 GIC     3379531 :             MemoryContextResetOnly(context);
     641                 : 
     642 ECB             :         /*
     643                 :          * If the freelist is full, just discard what's already in it.  See
     644                 :          * comments with context_freelists[].
     645                 :          */
     646 GIC     4943417 :         if (freelist->num_free >= MAX_FREE_CONTEXTS)
     647                 :         {
     648 CBC       23432 :             while (freelist->first_free != NULL)
     649 ECB             :             {
     650 CBC       23200 :                 AllocSetContext *oldset = freelist->first_free;
     651                 : 
     652           23200 :                 freelist->first_free = (AllocSetContext *) oldset->header.nextchild;
     653 GIC       23200 :                 freelist->num_free--;
     654                 : 
     655                 :                 /* All that remains is to free the header/initial block */
     656 GBC       23200 :                 free(oldset);
     657                 :             }
     658             232 :             Assert(freelist->num_free == 0);
     659                 :         }
     660 EUB             : 
     661                 :         /* Now add the just-deleted context to the freelist. */
     662 GIC     4943417 :         set->header.nextchild = (MemoryContext) freelist->first_free;
     663         4943417 :         freelist->first_free = set;
     664 GBC     4943417 :         freelist->num_free++;
     665                 : 
     666 GIC     4943417 :         return;
     667 EUB             :     }
     668                 : 
     669                 :     /* Free all blocks, except the keeper which is part of context header */
     670 UBC           0 :     while (block != NULL)
     671                 :     {
     672 UIC           0 :         AllocBlock  next = block->next;
     673 EUB             : 
     674 UIC           0 :         if (block != set->keeper)
     675               0 :             context->mem_allocated -= block->endptr - ((char *) block);
     676 EUB             : 
     677                 : #ifdef CLOBBER_FREED_MEMORY
     678 UIC           0 :         wipe_mem(block, block->freeptr - ((char *) block));
     679                 : #endif
     680                 : 
     681               0 :         if (block != set->keeper)
     682               0 :             free(block);
     683                 : 
     684               0 :         block = next;
     685                 :     }
     686                 : 
     687               0 :     Assert(context->mem_allocated == keepersize);
     688                 : 
     689                 :     /* Finally, free the context header, including the keeper block */
     690               0 :     free(set);
     691                 : }
     692                 : 
     693 ECB             : /*
     694                 :  * AllocSetAlloc
     695                 :  *      Returns pointer to allocated memory of given size or NULL if
     696                 :  *      request could not be completed; memory is added to the set.
     697                 :  *
     698                 :  * No request may exceed:
     699                 :  *      MAXALIGN_DOWN(SIZE_MAX) - ALLOC_BLOCKHDRSZ - ALLOC_CHUNKHDRSZ
     700                 :  * All callers use a much-lower limit.
     701                 :  *
     702                 :  * Note: when using valgrind, it doesn't matter how the returned allocation
     703                 :  * is marked, as mcxt.c will set it to UNDEFINED.  In some paths we will
     704                 :  * return space that is marked NOACCESS - AllocSetRealloc has to beware!
     705                 :  */
     706                 : void *
     707 GIC   625246354 : AllocSetAlloc(MemoryContext context, Size size)
     708 ECB             : {
     709 GIC   625246354 :     AllocSet    set = (AllocSet) context;
     710                 :     AllocBlock  block;
     711                 :     MemoryChunk *chunk;
     712 ECB             :     int         fidx;
     713                 :     Size        chunk_size;
     714                 :     Size        blksize;
     715                 : 
     716 GNC   625246354 :     Assert(AllocSetIsValid(set));
     717 ECB             : 
     718                 :     /*
     719                 :      * If requested size exceeds maximum for chunks, allocate an entire block
     720 EUB             :      * for this request.
     721                 :      */
     722 CBC   625246354 :     if (size > set->allocChunkLimit)
     723                 :     {
     724                 : #ifdef MEMORY_CONTEXT_CHECKING
     725                 :         /* ensure there's always space for the sentinel byte */
     726 GNC    11334379 :         chunk_size = MAXALIGN(size + 1);
     727                 : #else
     728 ECB             :         chunk_size = MAXALIGN(size);
     729                 : #endif
     730                 : 
     731 CBC    11334379 :         blksize = chunk_size + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
     732 GIC    11334379 :         block = (AllocBlock) malloc(blksize);
     733 CBC    11334379 :         if (block == NULL)
     734 UIC           0 :             return NULL;
     735                 : 
     736 CBC    11334379 :         context->mem_allocated += blksize;
     737                 : 
     738 GIC    11334379 :         block->aset = set;
     739 CBC    11334379 :         block->freeptr = block->endptr = ((char *) block) + blksize;
     740                 : 
     741 GNC    11334379 :         chunk = (MemoryChunk *) (((char *) block) + ALLOC_BLOCKHDRSZ);
     742                 : 
     743                 :         /* mark the MemoryChunk as externally managed */
     744        11334379 :         MemoryChunkSetHdrMaskExternal(chunk, MCTX_ASET_ID);
     745                 : 
     746                 : #ifdef MEMORY_CONTEXT_CHECKING
     747 GIC    11334379 :         chunk->requested_size = size;
     748                 :         /* set mark to catch clobber of "unused" space */
     749 GNC    11334379 :         Assert(size < chunk_size);
     750        11334379 :         set_sentinel(MemoryChunkGetPointer(chunk), size);
     751                 : #endif
     752                 : #ifdef RANDOMIZE_ALLOCATED_MEMORY
     753                 :         /* fill the allocated space with junk */
     754                 :         randomize_mem((char *) MemoryChunkGetPointer(chunk), size);
     755 ECB             : #endif
     756                 : 
     757                 :         /*
     758                 :          * Stick the new block underneath the active allocation block, if any,
     759                 :          * so that we don't lose the use of the space remaining therein.
     760                 :          */
     761 CBC    11334379 :         if (set->blocks != NULL)
     762                 :         {
     763 GIC    11334379 :             block->prev = set->blocks;
     764        11334379 :             block->next = set->blocks->next;
     765 GBC    11334379 :             if (block->next)
     766         9260544 :                 block->next->prev = block;
     767        11334379 :             set->blocks->next = block;
     768                 :         }
     769                 :         else
     770                 :         {
     771 UIC           0 :             block->prev = NULL;
     772               0 :             block->next = NULL;
     773               0 :             set->blocks = block;
     774                 :         }
     775                 : 
     776                 :         /* Ensure any padding bytes are marked NOACCESS. */
     777                 :         VALGRIND_MAKE_MEM_NOACCESS((char *) MemoryChunkGetPointer(chunk) + size,
     778                 :                                    chunk_size - size);
     779                 : 
     780                 :         /* Disallow external access to private part of chunk header. */
     781                 :         VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
     782                 : 
     783 GNC    11334379 :         return MemoryChunkGetPointer(chunk);
     784                 :     }
     785                 : 
     786                 :     /*
     787                 :      * Request is small enough to be treated as a chunk.  Look in the
     788                 :      * corresponding free list to see if there is a free chunk we could reuse.
     789                 :      * If one is found, remove it from the free list, make it again a member
     790                 :      * of the alloc set and return its data address.
     791                 :      *
     792                 :      * Note that we don't attempt to ensure there's space for the sentinel
     793                 :      * byte here.  We expect a large proportion of allocations to be for sizes
     794                 :      * which are already a power of 2.  If we were to always make space for a
     795                 :      * sentinel byte in MEMORY_CONTEXT_CHECKING builds, then we'd end up
     796                 :      * doubling the memory requirements for such allocations.
     797                 :      */
     798 CBC   613911975 :     fidx = AllocSetFreeIndex(size);
     799       613911975 :     chunk = set->freelist[fidx];
     800       613911975 :     if (chunk != NULL)
     801                 :     {
     802 GNC   223843982 :         AllocFreeListLink *link = GetFreeListLink(chunk);
     803                 : 
     804       223843982 :         Assert(fidx == MemoryChunkGetValue(chunk));
     805                 : 
     806                 :         /* pop this chunk off the freelist */
     807                 :         VALGRIND_MAKE_MEM_DEFINED(link, sizeof(AllocFreeListLink));
     808       223843982 :         set->freelist[fidx] = link->next;
     809                 :         VALGRIND_MAKE_MEM_NOACCESS(link, sizeof(AllocFreeListLink));
     810                 : 
     811 ECB             : #ifdef MEMORY_CONTEXT_CHECKING
     812 GIC   223843982 :         chunk->requested_size = size;
     813                 :         /* set mark to catch clobber of "unused" space */
     814 GNC   223843982 :         if (size < GetChunkSizeFromFreeListIdx(fidx))
     815       130931138 :             set_sentinel(MemoryChunkGetPointer(chunk), size);
     816                 : #endif
     817 ECB             : #ifdef RANDOMIZE_ALLOCATED_MEMORY
     818                 :         /* fill the allocated space with junk */
     819                 :         randomize_mem((char *) MemoryChunkGetPointer(chunk), size);
     820                 : #endif
     821                 : 
     822                 :         /* Ensure any padding bytes are marked NOACCESS. */
     823                 :         VALGRIND_MAKE_MEM_NOACCESS((char *) MemoryChunkGetPointer(chunk) + size,
     824                 :                                    GetChunkSizeFromFreeListIdx(fidx) - size);
     825                 : 
     826                 :         /* Disallow external access to private part of chunk header. */
     827                 :         VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
     828                 : 
     829 GNC   223843982 :         return MemoryChunkGetPointer(chunk);
     830                 :     }
     831                 : 
     832 ECB             :     /*
     833                 :      * Choose the actual chunk size to allocate.
     834                 :      */
     835 GNC   390067993 :     chunk_size = GetChunkSizeFromFreeListIdx(fidx);
     836 GIC   390067993 :     Assert(chunk_size >= size);
     837                 : 
     838 ECB             :     /*
     839                 :      * If there is enough room in the active allocation block, we will put the
     840                 :      * chunk into that block.  Else must start a new one.
     841                 :      */
     842 GIC   390067993 :     if ((block = set->blocks) != NULL)
     843                 :     {
     844       390067993 :         Size        availspace = block->endptr - block->freeptr;
     845 ECB             : 
     846 GIC   390067993 :         if (availspace < (chunk_size + ALLOC_CHUNKHDRSZ))
     847 ECB             :         {
     848                 :             /*
     849                 :              * The existing active (top) block does not have enough room for
     850                 :              * the requested allocation, but it might still have a useful
     851                 :              * amount of space in it.  Once we push it down in the block list,
     852                 :              * we'll never try to allocate more space from it. So, before we
     853                 :              * do that, carve up its free space into chunks that we can put on
     854                 :              * the set's freelists.
     855                 :              *
     856                 :              * Because we can only get here when there's less than
     857                 :              * ALLOC_CHUNK_LIMIT left in the block, this loop cannot iterate
     858                 :              * more than ALLOCSET_NUM_FREELISTS-1 times.
     859                 :              */
     860 GIC    10298307 :             while (availspace >= ((1 << ALLOC_MINBITS) + ALLOC_CHUNKHDRSZ))
     861                 :             {
     862                 :                 AllocFreeListLink *link;
     863         6459823 :                 Size        availchunk = availspace - ALLOC_CHUNKHDRSZ;
     864 CBC     6459823 :                 int         a_fidx = AllocSetFreeIndex(availchunk);
     865                 : 
     866                 :                 /*
     867 ECB             :                  * In most cases, we'll get back the index of the next larger
     868                 :                  * freelist than the one we need to put this chunk on.  The
     869                 :                  * exception is when availchunk is exactly a power of 2.
     870                 :                  */
     871 GNC     6459823 :                 if (availchunk != GetChunkSizeFromFreeListIdx(a_fidx))
     872                 :                 {
     873 GIC     5185206 :                     a_fidx--;
     874         5185206 :                     Assert(a_fidx >= 0);
     875 GNC     5185206 :                     availchunk = GetChunkSizeFromFreeListIdx(a_fidx);
     876                 :                 }
     877 ECB             : 
     878 GNC     6459823 :                 chunk = (MemoryChunk *) (block->freeptr);
     879 ECB             : 
     880                 :                 /* Prepare to initialize the chunk header. */
     881                 :                 VALGRIND_MAKE_MEM_UNDEFINED(chunk, ALLOC_CHUNKHDRSZ);
     882 GIC     6459823 :                 block->freeptr += (availchunk + ALLOC_CHUNKHDRSZ);
     883         6459823 :                 availspace -= (availchunk + ALLOC_CHUNKHDRSZ);
     884                 : 
     885                 :                 /* store the freelist index in the value field */
     886 GNC     6459823 :                 MemoryChunkSetHdrMask(chunk, block, a_fidx, MCTX_ASET_ID);
     887 ECB             : #ifdef MEMORY_CONTEXT_CHECKING
     888 GNC     6459823 :                 chunk->requested_size = InvalidAllocSize;    /* mark it free */
     889                 : #endif
     890                 :                 /* push this chunk onto the free list */
     891         6459823 :                 link = GetFreeListLink(chunk);
     892                 : 
     893                 :                 VALGRIND_MAKE_MEM_DEFINED(link, sizeof(AllocFreeListLink));
     894         6459823 :                 link->next = set->freelist[a_fidx];
     895                 :                 VALGRIND_MAKE_MEM_NOACCESS(link, sizeof(AllocFreeListLink));
     896                 : 
     897 GIC     6459823 :                 set->freelist[a_fidx] = chunk;
     898 ECB             :             }
     899                 :             /* Mark that we need to create a new block */
     900 CBC     3838484 :             block = NULL;
     901                 :         }
     902                 :     }
     903 ECB             : 
     904                 :     /*
     905                 :      * Time to create a new regular (multi-chunk) block?
     906                 :      */
     907 GIC   390067993 :     if (block == NULL)
     908                 :     {
     909 ECB             :         Size        required_size;
     910                 : 
     911                 :         /*
     912                 :          * The first such block has size initBlockSize, and we double the
     913                 :          * space in each succeeding block, but not more than maxBlockSize.
     914                 :          */
     915 GIC     3838484 :         blksize = set->nextBlockSize;
     916 CBC     3838484 :         set->nextBlockSize <<= 1;
     917 GIC     3838484 :         if (set->nextBlockSize > set->maxBlockSize)
     918          716481 :             set->nextBlockSize = set->maxBlockSize;
     919                 : 
     920                 :         /*
     921                 :          * If initBlockSize is less than ALLOC_CHUNK_LIMIT, we could need more
     922                 :          * space... but try to keep it a power of 2.
     923                 :          */
     924 CBC     3838484 :         required_size = chunk_size + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
     925         4244209 :         while (blksize < required_size)
     926          405725 :             blksize <<= 1;
     927 ECB             : 
     928                 :         /* Try to allocate it */
     929 GIC     3838484 :         block = (AllocBlock) malloc(blksize);
     930                 : 
     931                 :         /*
     932                 :          * We could be asking for pretty big blocks here, so cope if malloc
     933 ECB             :          * fails.  But give up if there's less than 1 MB or so available...
     934                 :          */
     935 CBC     3838484 :         while (block == NULL && blksize > 1024 * 1024)
     936                 :         {
     937 UIC           0 :             blksize >>= 1;
     938 LBC           0 :             if (blksize < required_size)
     939 UIC           0 :                 break;
     940               0 :             block = (AllocBlock) malloc(blksize);
     941                 :         }
     942                 : 
     943 GIC     3838484 :         if (block == NULL)
     944 LBC           0 :             return NULL;
     945                 : 
     946 GBC     3838484 :         context->mem_allocated += blksize;
     947 EUB             : 
     948 GBC     3838484 :         block->aset = set;
     949         3838484 :         block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
     950 GIC     3838484 :         block->endptr = ((char *) block) + blksize;
     951                 : 
     952 ECB             :         /* Mark unallocated space NOACCESS. */
     953 EUB             :         VALGRIND_MAKE_MEM_NOACCESS(block->freeptr,
     954                 :                                    blksize - ALLOC_BLOCKHDRSZ);
     955 ECB             : 
     956 GIC     3838484 :         block->prev = NULL;
     957 CBC     3838484 :         block->next = set->blocks;
     958         3838484 :         if (block->next)
     959         3838484 :             block->next->prev = block;
     960 GIC     3838484 :         set->blocks = block;
     961                 :     }
     962                 : 
     963                 :     /*
     964                 :      * OK, do the allocation
     965 ECB             :      */
     966 GNC   390067993 :     chunk = (MemoryChunk *) (block->freeptr);
     967 ECB             : 
     968                 :     /* Prepare to initialize the chunk header. */
     969                 :     VALGRIND_MAKE_MEM_UNDEFINED(chunk, ALLOC_CHUNKHDRSZ);
     970                 : 
     971 GIC   390067993 :     block->freeptr += (chunk_size + ALLOC_CHUNKHDRSZ);
     972       390067993 :     Assert(block->freeptr <= block->endptr);
     973                 : 
     974                 :     /* store the free list index in the value field */
     975 GNC   390067993 :     MemoryChunkSetHdrMask(chunk, block, fidx, MCTX_ASET_ID);
     976                 : 
     977                 : #ifdef MEMORY_CONTEXT_CHECKING
     978 GIC   390067993 :     chunk->requested_size = size;
     979                 :     /* set mark to catch clobber of "unused" space */
     980 GNC   390067993 :     if (size < chunk_size)
     981       269776560 :         set_sentinel(MemoryChunkGetPointer(chunk), size);
     982 ECB             : #endif
     983                 : #ifdef RANDOMIZE_ALLOCATED_MEMORY
     984                 :     /* fill the allocated space with junk */
     985                 :     randomize_mem((char *) MemoryChunkGetPointer(chunk), size);
     986                 : #endif
     987                 : 
     988                 :     /* Ensure any padding bytes are marked NOACCESS. */
     989                 :     VALGRIND_MAKE_MEM_NOACCESS((char *) MemoryChunkGetPointer(chunk) + size,
     990                 :                                chunk_size - size);
     991                 : 
     992                 :     /* Disallow external access to private part of chunk header. */
     993                 :     VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
     994                 : 
     995 GNC   390067993 :     return MemoryChunkGetPointer(chunk);
     996                 : }
     997                 : 
     998                 : /*
     999                 :  * AllocSetFree
    1000                 :  *      Frees allocated memory; memory is removed from the set.
    1001                 :  */
    1002                 : void
    1003       269680877 : AllocSetFree(void *pointer)
    1004                 : {
    1005                 :     AllocSet    set;
    1006       269680877 :     MemoryChunk *chunk = PointerGetMemoryChunk(pointer);
    1007                 : 
    1008                 :     /* Allow access to private part of chunk header. */
    1009                 :     VALGRIND_MAKE_MEM_DEFINED(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1010                 : 
    1011       269680877 :     if (MemoryChunkIsExternal(chunk))
    1012                 :     {
    1013                 :         /* Release single-chunk block. */
    1014        10355913 :         AllocBlock  block = ExternalChunkGetBlock(chunk);
    1015                 : 
    1016                 :         /*
    1017                 :          * Try to verify that we have a sane block pointer: the block header
    1018                 :          * should reference an aset and the freeptr should match the endptr.
    1019 EUB             :          */
    1020 GNC    10355913 :         if (!AllocBlockIsValid(block) || block->freeptr != block->endptr)
    1021 UIC           0 :             elog(ERROR, "could not find block containing chunk %p", chunk);
    1022                 : 
    1023 GNC    10355913 :         set = block->aset;
    1024                 : 
    1025                 : #ifdef MEMORY_CONTEXT_CHECKING
    1026                 :         {
    1027                 :             /* Test for someone scribbling on unused space in chunk */
    1028        10355913 :             Assert(chunk->requested_size < (block->endptr - (char *) pointer));
    1029        10355913 :             if (!sentinel_ok(pointer, chunk->requested_size))
    1030 UNC           0 :                 elog(WARNING, "detected write past chunk end in %s %p",
    1031                 :                      set->header.name, chunk);
    1032                 :         }
    1033                 : #endif
    1034                 : 
    1035 ECB             :         /* OK, remove block from aset's list and free it */
    1036 CBC    10355913 :         if (block->prev)
    1037 GBC    10355913 :             block->prev->next = block->next;
    1038                 :         else
    1039 UIC           0 :             set->blocks = block->next;
    1040 GIC    10355913 :         if (block->next)
    1041         8575345 :             block->next->prev = block->prev;
    1042                 : 
    1043 GNC    10355913 :         set->header.mem_allocated -= block->endptr - ((char *) block);
    1044 ECB             : 
    1045                 : #ifdef CLOBBER_FREED_MEMORY
    1046 GBC    10355913 :         wipe_mem(block, block->freeptr - ((char *) block));
    1047 ECB             : #endif
    1048 CBC    10355913 :         free(block);
    1049                 :     }
    1050 ECB             :     else
    1051                 :     {
    1052 GNC   259324964 :         AllocBlock  block = MemoryChunkGetBlock(chunk);
    1053                 :         int         fidx;
    1054                 :         AllocFreeListLink *link;
    1055                 : 
    1056                 :         /*
    1057                 :          * In this path, for speed reasons we just Assert that the referenced
    1058                 :          * block is good.  We can also Assert that the value field is sane.
    1059                 :          * Future field experience may show that these Asserts had better
    1060                 :          * become regular runtime test-and-elog checks.
    1061                 :          */
    1062       259324964 :         Assert(AllocBlockIsValid(block));
    1063       259324964 :         set = block->aset;
    1064                 : 
    1065       259324964 :         fidx = MemoryChunkGetValue(chunk);
    1066       259324964 :         Assert(FreeListIdxIsValid(fidx));
    1067       259324964 :         link = GetFreeListLink(chunk);
    1068                 : 
    1069                 : #ifdef MEMORY_CONTEXT_CHECKING
    1070                 :         /* Test for someone scribbling on unused space in chunk */
    1071       259324964 :         if (chunk->requested_size < GetChunkSizeFromFreeListIdx(fidx))
    1072       159341246 :             if (!sentinel_ok(pointer, chunk->requested_size))
    1073 UNC           0 :                 elog(WARNING, "detected write past chunk end in %s %p",
    1074                 :                      set->header.name, chunk);
    1075                 : #endif
    1076                 : 
    1077                 : #ifdef CLOBBER_FREED_MEMORY
    1078 GNC   259324964 :         wipe_mem(pointer, GetChunkSizeFromFreeListIdx(fidx));
    1079                 : #endif
    1080                 :         /* push this chunk onto the top of the free list */
    1081                 :         VALGRIND_MAKE_MEM_DEFINED(link, sizeof(AllocFreeListLink));
    1082       259324964 :         link->next = set->freelist[fidx];
    1083                 :         VALGRIND_MAKE_MEM_NOACCESS(link, sizeof(AllocFreeListLink));
    1084 GIC   259324964 :         set->freelist[fidx] = chunk;
    1085                 : 
    1086                 : #ifdef MEMORY_CONTEXT_CHECKING
    1087                 : 
    1088                 :         /*
    1089                 :          * Reset requested_size to InvalidAllocSize in chunks that are on free
    1090                 :          * list.
    1091                 :          */
    1092 GNC   259324964 :         chunk->requested_size = InvalidAllocSize;
    1093                 : #endif
    1094                 :     }
    1095 GIC   269680877 : }
    1096                 : 
    1097 ECB             : /*
    1098                 :  * AllocSetRealloc
    1099                 :  *      Returns new pointer to allocated memory of given size or NULL if
    1100                 :  *      request could not be completed; this memory is added to the set.
    1101                 :  *      Memory associated with given pointer is copied into the new memory,
    1102                 :  *      and the old memory is freed.
    1103                 :  *
    1104                 :  * Without MEMORY_CONTEXT_CHECKING, we don't know the old request size.  This
    1105                 :  * makes our Valgrind client requests less-precise, hazarding false negatives.
    1106                 :  * (In principle, we could use VALGRIND_GET_VBITS() to rediscover the old
    1107                 :  * request size.)
    1108 EUB             :  */
    1109                 : void *
    1110 GNC     2854224 : AllocSetRealloc(void *pointer, Size size)
    1111                 : {
    1112                 :     AllocBlock  block;
    1113                 :     AllocSet    set;
    1114         2854224 :     MemoryChunk *chunk = PointerGetMemoryChunk(pointer);
    1115                 :     Size        oldchksize;
    1116                 :     int         fidx;
    1117                 : 
    1118                 :     /* Allow access to private part of chunk header. */
    1119 ECB             :     VALGRIND_MAKE_MEM_DEFINED(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1120                 : 
    1121 GNC     2854224 :     if (MemoryChunkIsExternal(chunk))
    1122 ECB             :     {
    1123                 :         /*
    1124                 :          * The chunk must have been allocated as a single-chunk block.  Use
    1125                 :          * realloc() to make the containing block bigger, or smaller, with
    1126                 :          * minimum space wastage.
    1127                 :          */
    1128                 :         Size        chksize;
    1129                 :         Size        blksize;
    1130                 :         Size        oldblksize;
    1131                 : 
    1132 GNC      218722 :         block = ExternalChunkGetBlock(chunk);
    1133                 : 
    1134                 :         /*
    1135                 :          * Try to verify that we have a sane block pointer: the block header
    1136                 :          * should reference an aset and the freeptr should match the endptr.
    1137                 :          */
    1138          218722 :         if (!AllocBlockIsValid(block) || block->freeptr != block->endptr)
    1139 UNC           0 :             elog(ERROR, "could not find block containing chunk %p", chunk);
    1140                 : 
    1141 GNC      218722 :         set = block->aset;
    1142                 : 
    1143          218722 :         oldchksize = block->endptr - (char *) pointer;
    1144                 : 
    1145                 : #ifdef MEMORY_CONTEXT_CHECKING
    1146                 :         /* Test for someone scribbling on unused space in chunk */
    1147          218722 :         Assert(chunk->requested_size < oldchksize);
    1148          218722 :         if (!sentinel_ok(pointer, chunk->requested_size))
    1149 UNC           0 :             elog(WARNING, "detected write past chunk end in %s %p",
    1150                 :                  set->header.name, chunk);
    1151                 : #endif
    1152                 : 
    1153                 : #ifdef MEMORY_CONTEXT_CHECKING
    1154                 :         /* ensure there's always space for the sentinel byte */
    1155 GNC      218722 :         chksize = MAXALIGN(size + 1);
    1156                 : #else
    1157                 :         chksize = MAXALIGN(size);
    1158                 : #endif
    1159                 : 
    1160                 :         /* Do the realloc */
    1161 GIC      218722 :         blksize = chksize + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
    1162          218722 :         oldblksize = block->endptr - ((char *) block);
    1163                 : 
    1164          218722 :         block = (AllocBlock) realloc(block, blksize);
    1165          218722 :         if (block == NULL)
    1166 ECB             :         {
    1167                 :             /* Disallow external access to private part of chunk header. */
    1168                 :             VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1169 UIC           0 :             return NULL;
    1170                 :         }
    1171                 : 
    1172 ECB             :         /* updated separately, not to underflow when (oldblksize > blksize) */
    1173 GNC      218722 :         set->header.mem_allocated -= oldblksize;
    1174          218722 :         set->header.mem_allocated += blksize;
    1175 ECB             : 
    1176 GIC      218722 :         block->freeptr = block->endptr = ((char *) block) + blksize;
    1177 ECB             : 
    1178                 :         /* Update pointers since block has likely been moved */
    1179 GNC      218722 :         chunk = (MemoryChunk *) (((char *) block) + ALLOC_BLOCKHDRSZ);
    1180          218722 :         pointer = MemoryChunkGetPointer(chunk);
    1181 CBC      218722 :         if (block->prev)
    1182          218722 :             block->prev->next = block;
    1183 EUB             :         else
    1184 UIC           0 :             set->blocks = block;
    1185 GIC      218722 :         if (block->next)
    1186          206316 :             block->next->prev = block;
    1187                 : 
    1188 ECB             : #ifdef MEMORY_CONTEXT_CHECKING
    1189                 : #ifdef RANDOMIZE_ALLOCATED_MEMORY
    1190                 : 
    1191                 :         /*
    1192                 :          * We can only randomize the extra space if we know the prior request.
    1193                 :          * When using Valgrind, randomize_mem() also marks memory UNDEFINED.
    1194                 :          */
    1195                 :         if (size > chunk->requested_size)
    1196                 :             randomize_mem((char *) pointer + chunk->requested_size,
    1197                 :                           size - chunk->requested_size);
    1198                 : #else
    1199                 : 
    1200                 :         /*
    1201                 :          * If this is an increase, realloc() will have marked any
    1202 EUB             :          * newly-allocated part (from oldchksize to chksize) UNDEFINED, but we
    1203                 :          * also need to adjust trailing bytes from the old allocation (from
    1204                 :          * chunk->requested_size to oldchksize) as they are marked NOACCESS.
    1205                 :          * Make sure not to mark too many bytes in case chunk->requested_size
    1206 ECB             :          * < size < oldchksize.
    1207                 :          */
    1208                 : #ifdef USE_VALGRIND
    1209                 :         if (Min(size, oldchksize) > chunk->requested_size)
    1210                 :             VALGRIND_MAKE_MEM_UNDEFINED((char *) pointer + chunk->requested_size,
    1211                 :                                         Min(size, oldchksize) - chunk->requested_size);
    1212                 : #endif
    1213                 : #endif
    1214                 : 
    1215 CBC      218722 :         chunk->requested_size = size;
    1216 EUB             :         /* set mark to catch clobber of "unused" space */
    1217 GNC      218722 :         Assert(size < chksize);
    1218          218722 :         set_sentinel(pointer, size);
    1219                 : #else                           /* !MEMORY_CONTEXT_CHECKING */
    1220                 : 
    1221                 :         /*
    1222                 :          * We may need to adjust marking of bytes from the old allocation as
    1223                 :          * some of them may be marked NOACCESS.  We don't know how much of the
    1224                 :          * old chunk size was the requested size; it could have been as small
    1225                 :          * as one byte.  We have to be conservative and just mark the entire
    1226                 :          * old portion DEFINED.  Make sure not to mark memory beyond the new
    1227                 :          * allocation in case it's smaller than the old one.
    1228                 :          */
    1229                 :         VALGRIND_MAKE_MEM_DEFINED(pointer, Min(size, oldchksize));
    1230                 : #endif
    1231                 : 
    1232                 :         /* Ensure any padding bytes are marked NOACCESS. */
    1233                 :         VALGRIND_MAKE_MEM_NOACCESS((char *) pointer + size, chksize - size);
    1234                 : 
    1235                 :         /* Disallow external access to private part of chunk header. */
    1236                 :         VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1237                 : 
    1238 GIC      218722 :         return pointer;
    1239                 :     }
    1240                 : 
    1241 GNC     2635502 :     block = MemoryChunkGetBlock(chunk);
    1242                 : 
    1243                 :     /*
    1244                 :      * In this path, for speed reasons we just Assert that the referenced
    1245                 :      * block is good. We can also Assert that the value field is sane. Future
    1246                 :      * field experience may show that these Asserts had better become regular
    1247                 :      * runtime test-and-elog checks.
    1248                 :      */
    1249         2635502 :     Assert(AllocBlockIsValid(block));
    1250         2635502 :     set = block->aset;
    1251                 : 
    1252         2635502 :     fidx = MemoryChunkGetValue(chunk);
    1253         2635502 :     Assert(FreeListIdxIsValid(fidx));
    1254         2635502 :     oldchksize = GetChunkSizeFromFreeListIdx(fidx);
    1255                 : 
    1256                 : #ifdef MEMORY_CONTEXT_CHECKING
    1257                 :     /* Test for someone scribbling on unused space in chunk */
    1258         2635502 :     if (chunk->requested_size < oldchksize)
    1259          850894 :         if (!sentinel_ok(pointer, chunk->requested_size))
    1260 UNC           0 :             elog(WARNING, "detected write past chunk end in %s %p",
    1261                 :                  set->header.name, chunk);
    1262                 : #endif
    1263                 : 
    1264                 :     /*
    1265                 :      * Chunk sizes are aligned to power of 2 in AllocSetAlloc().  Maybe the
    1266                 :      * allocated area already is >= the new size.  (In particular, we will
    1267                 :      * fall out here if the requested size is a decrease.)
    1268                 :      */
    1269 GNC     2635502 :     if (oldchksize >= size)
    1270 ECB             :     {
    1271                 : #ifdef MEMORY_CONTEXT_CHECKING
    1272 CBC      867732 :         Size        oldrequest = chunk->requested_size;
    1273 ECB             : 
    1274                 : #ifdef RANDOMIZE_ALLOCATED_MEMORY
    1275                 :         /* We can only fill the extra space if we know the prior request */
    1276                 :         if (size > oldrequest)
    1277                 :             randomize_mem((char *) pointer + oldrequest,
    1278                 :                           size - oldrequest);
    1279                 : #endif
    1280                 : 
    1281 GIC      867732 :         chunk->requested_size = size;
    1282                 : 
    1283                 :         /*
    1284                 :          * If this is an increase, mark any newly-available part UNDEFINED.
    1285                 :          * Otherwise, mark the obsolete part NOACCESS.
    1286                 :          */
    1287                 :         if (size > oldrequest)
    1288                 :             VALGRIND_MAKE_MEM_UNDEFINED((char *) pointer + oldrequest,
    1289                 :                                         size - oldrequest);
    1290                 :         else
    1291                 :             VALGRIND_MAKE_MEM_NOACCESS((char *) pointer + size,
    1292                 :                                        oldchksize - size);
    1293 ECB             : 
    1294                 :         /* set mark to catch clobber of "unused" space */
    1295 GIC      867732 :         if (size < oldchksize)
    1296 CBC      854119 :             set_sentinel(pointer, size);
    1297                 : #else                           /* !MEMORY_CONTEXT_CHECKING */
    1298                 : 
    1299                 :         /*
    1300                 :          * We don't have the information to determine whether we're growing
    1301                 :          * the old request or shrinking it, so we conservatively mark the
    1302                 :          * entire new allocation DEFINED.
    1303                 :          */
    1304 ECB             :         VALGRIND_MAKE_MEM_NOACCESS(pointer, oldchksize);
    1305                 :         VALGRIND_MAKE_MEM_DEFINED(pointer, size);
    1306                 : #endif
    1307                 : 
    1308                 :         /* Disallow external access to private part of chunk header. */
    1309                 :         VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1310                 : 
    1311 GIC      867732 :         return pointer;
    1312                 :     }
    1313 ECB             :     else
    1314                 :     {
    1315 EUB             :         /*
    1316                 :          * Enlarge-a-small-chunk case.  We just do this by brute force, ie,
    1317                 :          * allocate a new chunk and copy the data.  Since we know the existing
    1318                 :          * data isn't huge, this won't involve any great memcpy expense, so
    1319                 :          * it's not worth being smarter.  (At one time we tried to avoid
    1320                 :          * memcpy when it was possible to enlarge the chunk in-place, but that
    1321                 :          * turns out to misbehave unpleasantly for repeated cycles of
    1322                 :          * palloc/repalloc/pfree: the eventually freed chunks go into the
    1323                 :          * wrong freelist for the next initial palloc request, and so we leak
    1324 ECB             :          * memory indefinitely.  See pgsql-hackers archives for 2007-08-11.)
    1325                 :          */
    1326                 :         AllocPointer newPointer;
    1327                 :         Size        oldsize;
    1328                 : 
    1329                 :         /* allocate new chunk */
    1330 GIC     1767770 :         newPointer = AllocSetAlloc((MemoryContext) set, size);
    1331                 : 
    1332                 :         /* leave immediately if request was not completed */
    1333         1767770 :         if (newPointer == NULL)
    1334                 :         {
    1335                 :             /* Disallow external access to private part of chunk header. */
    1336 ECB             :             VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1337 UIC           0 :             return NULL;
    1338                 :         }
    1339                 : 
    1340                 :         /*
    1341                 :          * AllocSetAlloc() may have returned a region that is still NOACCESS.
    1342                 :          * Change it to UNDEFINED for the moment; memcpy() will then transfer
    1343                 :          * definedness from the old allocation to the new.  If we know the old
    1344                 :          * allocation, copy just that much.  Otherwise, make the entire old
    1345                 :          * chunk defined to avoid errors as we copy the currently-NOACCESS
    1346                 :          * trailing bytes.
    1347                 :          */
    1348                 :         VALGRIND_MAKE_MEM_UNDEFINED(newPointer, size);
    1349                 : #ifdef MEMORY_CONTEXT_CHECKING
    1350 CBC     1767770 :         oldsize = chunk->requested_size;
    1351 ECB             : #else
    1352                 :         oldsize = oldchksize;
    1353                 :         VALGRIND_MAKE_MEM_DEFINED(pointer, oldsize);
    1354                 : #endif
    1355                 : 
    1356                 :         /* transfer existing data (certain to fit) */
    1357 GIC     1767770 :         memcpy(newPointer, pointer, oldsize);
    1358                 : 
    1359                 :         /* free old chunk */
    1360 GNC     1767770 :         AllocSetFree(pointer);
    1361                 : 
    1362 GIC     1767770 :         return newPointer;
    1363                 :     }
    1364                 : }
    1365                 : 
    1366                 : /*
    1367                 :  * AllocSetGetChunkContext
    1368                 :  *      Return the MemoryContext that 'pointer' belongs to.
    1369                 :  */
    1370                 : MemoryContext
    1371 GNC     4837875 : AllocSetGetChunkContext(void *pointer)
    1372                 : {
    1373         4837875 :     MemoryChunk *chunk = PointerGetMemoryChunk(pointer);
    1374                 :     AllocBlock  block;
    1375                 :     AllocSet    set;
    1376                 : 
    1377         4837875 :     if (MemoryChunkIsExternal(chunk))
    1378          218722 :         block = ExternalChunkGetBlock(chunk);
    1379                 :     else
    1380         4619153 :         block = (AllocBlock) MemoryChunkGetBlock(chunk);
    1381                 : 
    1382         4837875 :     Assert(AllocBlockIsValid(block));
    1383         4837875 :     set = block->aset;
    1384                 : 
    1385         4837875 :     return &set->header;
    1386                 : }
    1387                 : 
    1388 ECB             : /*
    1389                 :  * AllocSetGetChunkSpace
    1390                 :  *      Given a currently-allocated chunk, determine the total space
    1391                 :  *      it occupies (including all memory-allocation overhead).
    1392                 :  */
    1393                 : Size
    1394 GNC    21026289 : AllocSetGetChunkSpace(void *pointer)
    1395                 : {
    1396        21026289 :     MemoryChunk *chunk = PointerGetMemoryChunk(pointer);
    1397                 :     int         fidx;
    1398                 : 
    1399        21026289 :     if (MemoryChunkIsExternal(chunk))
    1400                 :     {
    1401          515544 :         AllocBlock  block = ExternalChunkGetBlock(chunk);
    1402                 : 
    1403          515544 :         Assert(AllocBlockIsValid(block));
    1404          515544 :         return block->endptr - (char *) chunk;
    1405                 :     }
    1406                 : 
    1407        20510745 :     fidx = MemoryChunkGetValue(chunk);
    1408        20510745 :     Assert(FreeListIdxIsValid(fidx));
    1409        20510745 :     return GetChunkSizeFromFreeListIdx(fidx) + ALLOC_CHUNKHDRSZ;
    1410                 : }
    1411                 : 
    1412                 : /*
    1413                 :  * AllocSetIsEmpty
    1414 ECB             :  *      Is an allocset empty of any allocated space?
    1415                 :  */
    1416                 : bool
    1417 CBC        4330 : AllocSetIsEmpty(MemoryContext context)
    1418                 : {
    1419 GNC        4330 :     Assert(AllocSetIsValid(context));
    1420                 : 
    1421                 :     /*
    1422                 :      * For now, we say "empty" only if the context is new or just reset. We
    1423 EUB             :      * could examine the freelists to determine if all space has been freed,
    1424                 :      * but it's not really worth the trouble for present uses of this
    1425                 :      * functionality.
    1426                 :      */
    1427 GIC        4330 :     if (context->isReset)
    1428            4318 :         return true;
    1429              12 :     return false;
    1430                 : }
    1431                 : 
    1432                 : /*
    1433                 :  * AllocSetStats
    1434                 :  *      Compute stats about memory consumption of an allocset.
    1435                 :  *
    1436 ECB             :  * printfunc: if not NULL, pass a human-readable stats string to this.
    1437                 :  * passthru: pass this pointer through to printfunc.
    1438                 :  * totals: if not NULL, add stats about this context into *totals.
    1439                 :  * print_to_stderr: print stats to stderr if true, elog otherwise.
    1440                 :  */
    1441                 : void
    1442 GIC        1499 : AllocSetStats(MemoryContext context,
    1443 ECB             :               MemoryStatsPrintFunc printfunc, void *passthru,
    1444                 :               MemoryContextCounters *totals, bool print_to_stderr)
    1445                 : {
    1446 CBC        1499 :     AllocSet    set = (AllocSet) context;
    1447 GIC        1499 :     Size        nblocks = 0;
    1448 CBC        1499 :     Size        freechunks = 0;
    1449                 :     Size        totalspace;
    1450 GIC        1499 :     Size        freespace = 0;
    1451                 :     AllocBlock  block;
    1452                 :     int         fidx;
    1453                 : 
    1454 GNC        1499 :     Assert(AllocSetIsValid(set));
    1455                 : 
    1456                 :     /* Include context header in totalspace */
    1457 GIC        1499 :     totalspace = MAXALIGN(sizeof(AllocSetContext));
    1458                 : 
    1459 CBC        4216 :     for (block = set->blocks; block != NULL; block = block->next)
    1460                 :     {
    1461            2717 :         nblocks++;
    1462 GIC        2717 :         totalspace += block->endptr - ((char *) block);
    1463            2717 :         freespace += block->endptr - block->freeptr;
    1464                 :     }
    1465 CBC       17988 :     for (fidx = 0; fidx < ALLOCSET_NUM_FREELISTS; fidx++)
    1466 ECB             :     {
    1467 GNC       16489 :         Size        chksz = GetChunkSizeFromFreeListIdx(fidx);
    1468           16489 :         MemoryChunk *chunk = set->freelist[fidx];
    1469 ECB             : 
    1470 GNC       21407 :         while (chunk != NULL)
    1471 ECB             :         {
    1472 GNC        4918 :             AllocFreeListLink *link = GetFreeListLink(chunk);
    1473                 : 
    1474            4918 :             Assert(MemoryChunkGetValue(chunk) == fidx);
    1475                 : 
    1476 GIC        4918 :             freechunks++;
    1477 GNC        4918 :             freespace += chksz + ALLOC_CHUNKHDRSZ;
    1478                 : 
    1479                 :             VALGRIND_MAKE_MEM_DEFINED(link, sizeof(AllocFreeListLink));
    1480            4918 :             chunk = link->next;
    1481                 :             VALGRIND_MAKE_MEM_NOACCESS(link, sizeof(AllocFreeListLink));
    1482                 :         }
    1483                 :     }
    1484                 : 
    1485 GIC        1499 :     if (printfunc)
    1486                 :     {
    1487                 :         char        stats_string[200];
    1488                 : 
    1489             767 :         snprintf(stats_string, sizeof(stats_string),
    1490 ECB             :                  "%zu total in %zu blocks; %zu free (%zu chunks); %zu used",
    1491                 :                  totalspace, nblocks, freespace, freechunks,
    1492                 :                  totalspace - freespace);
    1493 GIC         767 :         printfunc(context, passthru, stats_string, print_to_stderr);
    1494                 :     }
    1495 ECB             : 
    1496 GIC        1499 :     if (totals)
    1497 ECB             :     {
    1498 GIC        1499 :         totals->nblocks += nblocks;
    1499 CBC        1499 :         totals->freechunks += freechunks;
    1500            1499 :         totals->totalspace += totalspace;
    1501 GIC        1499 :         totals->freespace += freespace;
    1502                 :     }
    1503 CBC        1499 : }
    1504 ECB             : 
    1505                 : 
    1506                 : #ifdef MEMORY_CONTEXT_CHECKING
    1507                 : 
    1508                 : /*
    1509                 :  * AllocSetCheck
    1510                 :  *      Walk through chunks and check consistency of memory.
    1511                 :  *
    1512                 :  * NOTE: report errors as WARNING, *not* ERROR or FATAL.  Otherwise you'll
    1513                 :  * find yourself in an infinite loop when trouble occurs, because this
    1514                 :  * routine will be entered again when elog cleanup tries to release memory!
    1515                 :  */
    1516                 : void
    1517 GIC    98632521 : AllocSetCheck(MemoryContext context)
    1518                 : {
    1519        98632521 :     AllocSet    set = (AllocSet) context;
    1520        98632521 :     const char *name = set->header.name;
    1521                 :     AllocBlock  prevblock;
    1522                 :     AllocBlock  block;
    1523 CBC    98632521 :     Size        total_allocated = 0;
    1524 ECB             : 
    1525 CBC    98632521 :     for (prevblock = NULL, block = set->blocks;
    1526 GIC   275105514 :          block != NULL;
    1527       176472993 :          prevblock = block, block = block->next)
    1528                 :     {
    1529       176472993 :         char       *bpoz = ((char *) block) + ALLOC_BLOCKHDRSZ;
    1530       176472993 :         long        blk_used = block->freeptr - bpoz;
    1531       176472993 :         long        blk_data = 0;
    1532       176472993 :         long        nchunks = 0;
    1533 GNC   176472993 :         bool        has_external_chunk = false;
    1534                 : 
    1535 GIC   176472993 :         if (set->keeper == block)
    1536        98632521 :             total_allocated += block->endptr - ((char *) set);
    1537                 :         else
    1538        77840472 :             total_allocated += block->endptr - ((char *) block);
    1539 ECB             : 
    1540                 :         /*
    1541                 :          * Empty block - empty can be keeper-block only
    1542                 :          */
    1543 CBC   176472993 :         if (!blk_used)
    1544 ECB             :         {
    1545 CBC     2679725 :             if (set->keeper != block)
    1546 UIC           0 :                 elog(WARNING, "problem in alloc set %s: empty block %p",
    1547 ECB             :                      name, block);
    1548                 :         }
    1549                 : 
    1550                 :         /*
    1551                 :          * Check block header fields
    1552                 :          */
    1553 GIC   176472993 :         if (block->aset != set ||
    1554 CBC   176472993 :             block->prev != prevblock ||
    1555 GIC   176472993 :             block->freeptr < bpoz ||
    1556 CBC   176472993 :             block->freeptr > block->endptr)
    1557 UIC           0 :             elog(WARNING, "problem in alloc set %s: corrupt header in block %p",
    1558 ECB             :                  name, block);
    1559                 : 
    1560                 :         /*
    1561                 :          * Chunk walker
    1562                 :          */
    1563 GIC  3967174220 :         while (bpoz < block->freeptr)
    1564 ECB             :         {
    1565 GNC  3790701227 :             MemoryChunk *chunk = (MemoryChunk *) bpoz;
    1566                 :             Size        chsize,
    1567 ECB             :                         dsize;
    1568                 : 
    1569                 :             /* Allow access to private part of chunk header. */
    1570                 :             VALGRIND_MAKE_MEM_DEFINED(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1571                 : 
    1572 GNC  3790701227 :             if (MemoryChunkIsExternal(chunk))
    1573                 :             {
    1574         5193595 :                 chsize = block->endptr - (char *) MemoryChunkGetPointer(chunk); /* aligned chunk size */
    1575         5193595 :                 has_external_chunk = true;
    1576                 : 
    1577                 :                 /* make sure this chunk consumes the entire block */
    1578         5193595 :                 if (chsize + ALLOC_CHUNKHDRSZ != blk_used)
    1579 UNC           0 :                     elog(WARNING, "problem in alloc set %s: bad single-chunk %p in block %p",
    1580                 :                          name, chunk, block);
    1581                 :             }
    1582                 :             else
    1583                 :             {
    1584 GNC  3785507632 :                 int         fidx = MemoryChunkGetValue(chunk);
    1585                 : 
    1586      3785507632 :                 if (!FreeListIdxIsValid(fidx))
    1587 UNC           0 :                     elog(WARNING, "problem in alloc set %s: bad chunk size for chunk %p in block %p",
    1588                 :                          name, chunk, block);
    1589                 : 
    1590 GNC  3785507632 :                 chsize = GetChunkSizeFromFreeListIdx(fidx); /* aligned chunk size */
    1591                 : 
    1592                 :                 /*
    1593                 :                  * Check the stored block offset correctly references this
    1594                 :                  * block.
    1595                 :                  */
    1596      3785507632 :                 if (block != MemoryChunkGetBlock(chunk))
    1597 UNC           0 :                     elog(WARNING, "problem in alloc set %s: bad block offset for chunk %p in block %p",
    1598                 :                          name, chunk, block);
    1599                 :             }
    1600 CBC  3790701227 :             dsize = chunk->requested_size;   /* real data */
    1601 ECB             : 
    1602                 :             /* an allocated chunk's requested size must be <= the chsize */
    1603 GNC  3790701227 :             if (dsize != InvalidAllocSize && dsize > chsize)
    1604 UIC           0 :                 elog(WARNING, "problem in alloc set %s: req size > alloc size for chunk %p in block %p",
    1605                 :                      name, chunk, block);
    1606                 : 
    1607                 :             /* chsize must not be smaller than the first freelist's size */
    1608 GIC  3790701227 :             if (chsize < (1 << ALLOC_MINBITS))
    1609 LBC           0 :                 elog(WARNING, "problem in alloc set %s: bad size %zu for chunk %p in block %p",
    1610                 :                      name, chsize, chunk, block);
    1611                 : 
    1612                 :             /*
    1613                 :              * Check for overwrite of padding space in an allocated chunk.
    1614                 :              */
    1615 GNC  3790701227 :             if (dsize != InvalidAllocSize && dsize < chsize &&
    1616 GIC  2548394979 :                 !sentinel_ok(chunk, ALLOC_CHUNKHDRSZ + dsize))
    1617 UIC           0 :                 elog(WARNING, "problem in alloc set %s: detected write past chunk end in block %p, chunk %p",
    1618                 :                      name, block, chunk);
    1619                 : 
    1620                 :             /*
    1621                 :              * If chunk is allocated, disallow external access to private part
    1622                 :              * of chunk header.
    1623                 :              */
    1624                 :             if (dsize != InvalidAllocSize)
    1625 ECB             :                 VALGRIND_MAKE_MEM_NOACCESS(chunk, ALLOCCHUNK_PRIVATE_LEN);
    1626                 : 
    1627 CBC  3790701227 :             blk_data += chsize;
    1628      3790701227 :             nchunks++;
    1629                 : 
    1630 GIC  3790701227 :             bpoz += ALLOC_CHUNKHDRSZ + chsize;
    1631 ECB             :         }
    1632                 : 
    1633 CBC   176472993 :         if ((blk_data + (nchunks * ALLOC_CHUNKHDRSZ)) != blk_used)
    1634 LBC           0 :             elog(WARNING, "problem in alloc set %s: found inconsistent memory block %p",
    1635 ECB             :                  name, block);
    1636                 : 
    1637 GNC   176472993 :         if (has_external_chunk && nchunks > 1)
    1638 UNC           0 :             elog(WARNING, "problem in alloc set %s: external chunk on non-dedicated block %p",
    1639                 :                  name, block);
    1640                 :     }
    1641 ECB             : 
    1642 CBC    98632521 :     Assert(total_allocated == context->mem_allocated);
    1643        98632521 : }
    1644 ECB             : 
    1645                 : #endif                          /* MEMORY_CONTEXT_CHECKING */
        

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