Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : * wait_event.h
3 : : * Definitions related to wait event reporting
4 : : *
5 : : * Copyright (c) 2001-2024, PostgreSQL Global Development Group
6 : : *
7 : : * src/include/utils/wait_event.h
8 : : * ----------
9 : : */
10 : : #ifndef WAIT_EVENT_H
11 : : #define WAIT_EVENT_H
12 : :
13 : :
14 : : /* ----------
15 : : * Wait Classes
16 : : * ----------
17 : : */
18 : : #define PG_WAIT_LWLOCK 0x01000000U
19 : : #define PG_WAIT_LOCK 0x03000000U
20 : : #define PG_WAIT_BUFFERPIN 0x04000000U
21 : : #define PG_WAIT_ACTIVITY 0x05000000U
22 : : #define PG_WAIT_CLIENT 0x06000000U
23 : : #define PG_WAIT_EXTENSION 0x07000000U
24 : : #define PG_WAIT_IPC 0x08000000U
25 : : #define PG_WAIT_TIMEOUT 0x09000000U
26 : : #define PG_WAIT_IO 0x0A000000U
27 : :
28 : : /* enums for wait events */
29 : : #include "utils/wait_event_types.h"
30 : :
31 : : extern const char *pgstat_get_wait_event(uint32 wait_event_info);
32 : : extern const char *pgstat_get_wait_event_type(uint32 wait_event_info);
33 : : static inline void pgstat_report_wait_start(uint32 wait_event_info);
34 : : static inline void pgstat_report_wait_end(void);
35 : : extern void pgstat_set_wait_event_storage(uint32 *wait_event_info);
36 : : extern void pgstat_reset_wait_event_storage(void);
37 : :
38 : : extern PGDLLIMPORT uint32 *my_wait_event_info;
39 : :
40 : :
41 : : /* ----------
42 : : * Wait Events - Extension
43 : : *
44 : : * Use this category when the server process is waiting for some condition
45 : : * defined by an extension module.
46 : : *
47 : : * Extensions can define their own wait events in this category. They should
48 : : * call WaitEventExtensionNew() with a wait event string. If the wait event
49 : : * associated to a string is already allocated, it returns the wait event
50 : : * information to use. If not, it gets one wait event ID allocated from
51 : : * a shared counter, associates the string to the ID in the shared dynamic
52 : : * hash and returns the wait event information.
53 : : *
54 : : * The ID retrieved can be used with pgstat_report_wait_start() or equivalent.
55 : : */
56 : : typedef enum
57 : : {
58 : : WAIT_EVENT_EXTENSION = PG_WAIT_EXTENSION,
59 : : WAIT_EVENT_EXTENSION_FIRST_USER_DEFINED,
60 : : } WaitEventExtension;
61 : :
62 : : extern void WaitEventExtensionShmemInit(void);
63 : : extern Size WaitEventExtensionShmemSize(void);
64 : :
65 : : extern uint32 WaitEventExtensionNew(const char *wait_event_name);
66 : : extern char **GetWaitEventExtensionNames(int *nwaitevents);
67 : :
68 : : /* ----------
69 : : * pgstat_report_wait_start() -
70 : : *
71 : : * Called from places where server process needs to wait. This is called
72 : : * to report wait event information. The wait information is stored
73 : : * as 4-bytes where first byte represents the wait event class (type of
74 : : * wait, for different types of wait, refer WaitClass) and the next
75 : : * 3-bytes represent the actual wait event. Currently 2-bytes are used
76 : : * for wait event which is sufficient for current usage, 1-byte is
77 : : * reserved for future usage.
78 : : *
79 : : * Historically we used to make this reporting conditional on
80 : : * pgstat_track_activities, but the check for that seems to add more cost
81 : : * than it saves.
82 : : *
83 : : * my_wait_event_info initially points to local memory, making it safe to
84 : : * call this before MyProc has been initialized.
85 : : * ----------
86 : : */
87 : : static inline void
1108 andres@anarazel.de 88 :CBC 13811577 : pgstat_report_wait_start(uint32 wait_event_info)
89 : : {
90 : : /*
91 : : * Since this is a four-byte field which is always read and written as
92 : : * four-bytes, updates are atomic.
93 : : */
1107 94 : 13811577 : *(volatile uint32 *) my_wait_event_info = wait_event_info;
1108 95 : 13811577 : }
96 : :
97 : : /* ----------
98 : : * pgstat_report_wait_end() -
99 : : *
100 : : * Called to report end of a wait.
101 : : * ----------
102 : : */
103 : : static inline void
104 : 13839670 : pgstat_report_wait_end(void)
105 : : {
106 : : /* see pgstat_report_wait_start() */
1107 107 : 13839670 : *(volatile uint32 *) my_wait_event_info = 0;
1108 108 : 13839670 : }
109 : :
110 : :
111 : : #endif /* WAIT_EVENT_H */
|
