blob: f719feadb050a4b25a9c74f3c4e5289fe560463f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
/*-------------------------------------------------------------------------
*
* waitlsn.h
* Declarations for LSN replay waiting routines.
*
* Copyright (c) 2024, PostgreSQL Global Development Group
*
* src/include/commands/waitlsn.h
*
*-------------------------------------------------------------------------
*/
#ifndef WAIT_LSN_H
#define WAIT_LSN_H
#include "lib/pairingheap.h"
#include "postgres.h"
#include "port/atomics.h"
#include "storage/latch.h"
#include "storage/spin.h"
#include "tcop/dest.h"
/*
* WaitLSNProcInfo - the shared memory structure representing information
* about the single process, which may wait for LSN replay. An item of
* waitLSN->procInfos array.
*/
typedef struct WaitLSNProcInfo
{
/* LSN, which this process is waiting for */
XLogRecPtr waitLSN;
/*
* A pointer to the latch, which should be set once the waitLSN is
* replayed.
*/
Latch *latch;
/* A pairing heap node for participation in waitLSNState->waitersHeap */
pairingheap_node phNode;
/*
* A flag indicating that this item is present in
* waitLSNState->waitersHeap
*/
bool inHeap;
} WaitLSNProcInfo;
/*
* WaitLSNState - the shared memory state for the replay LSN waiting facility.
*/
typedef struct WaitLSNState
{
/*
* The minimum LSN value some process is waiting for. Used for the
* fast-path checking if we need to wake up any waiters after replaying a
* WAL record. Could be read lock-less. Update protected by WaitLSNLock.
*/
pg_atomic_uint64 minWaitedLSN;
/*
* A pairing heap of waiting processes order by LSN values (least LSN is
* on top). Protected by WaitLSNLock.
*/
pairingheap waitersHeap;
/*
* An array with per-process information, indexed by the process number.
* Protected by WaitLSNLock.
*/
WaitLSNProcInfo procInfos[FLEXIBLE_ARRAY_MEMBER];
} WaitLSNState;
extern PGDLLIMPORT WaitLSNState *waitLSNState;
extern Size WaitLSNShmemSize(void);
extern void WaitLSNShmemInit(void);
extern void WaitLSNSetLatches(XLogRecPtr currentLSN);
extern void WaitLSNCleanup(void);
#endif /* WAIT_LSN_H */
|
