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
|
/*-------------------------------------------------------------------------
*
* procsignal.h
* Routines for interprocess signaling
*
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/storage/procsignal.h
*
*-------------------------------------------------------------------------
*/
#ifndef PROCSIGNAL_H
#define PROCSIGNAL_H
#include "storage/backendid.h"
/*
* Reasons for signaling a Postgres child process (a backend or an auxiliary
* process, like checkpointer). We can cope with concurrent signals for different
* reasons. However, if the same reason is signaled multiple times in quick
* succession, the process is likely to observe only one notification of it.
* This is okay for the present uses.
*
* Also, because of race conditions, it's important that all the signals be
* defined so that no harm is done if a process mistakenly receives one.
*/
typedef enum
{
PROCSIG_CATCHUP_INTERRUPT, /* sinval catchup interrupt */
PROCSIG_NOTIFY_INTERRUPT, /* listen/notify interrupt */
PROCSIG_PARALLEL_MESSAGE, /* message from cooperating parallel backend */
PROCSIG_WALSND_INIT_STOPPING, /* ask walsenders to prepare for shutdown */
PROCSIG_BARRIER, /* global barrier interrupt */
PROCSIG_LOG_MEMORY_CONTEXT, /* ask backend to log the memory contexts */
/* Recovery conflict reasons */
PROCSIG_RECOVERY_CONFLICT_DATABASE,
PROCSIG_RECOVERY_CONFLICT_TABLESPACE,
PROCSIG_RECOVERY_CONFLICT_LOCK,
PROCSIG_RECOVERY_CONFLICT_SNAPSHOT,
PROCSIG_RECOVERY_CONFLICT_BUFFERPIN,
PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK,
NUM_PROCSIGNALS /* Must be last! */
} ProcSignalReason;
typedef enum
{
/*
* XXX. PROCSIGNAL_BARRIER_PLACEHOLDER should be replaced when the first
* real user of the ProcSignalBarrier mechanism is added. It's just here
* for now because we can't have an empty enum.
*/
PROCSIGNAL_BARRIER_PLACEHOLDER = 0
} ProcSignalBarrierType;
/*
* prototypes for functions in procsignal.c
*/
extern Size ProcSignalShmemSize(void);
extern void ProcSignalShmemInit(void);
extern void ProcSignalInit(int pss_idx);
extern int SendProcSignal(pid_t pid, ProcSignalReason reason,
BackendId backendId);
extern uint64 EmitProcSignalBarrier(ProcSignalBarrierType type);
extern void WaitForProcSignalBarrier(uint64 generation);
extern void ProcessProcSignalBarrier(void);
extern void procsignal_sigusr1_handler(SIGNAL_ARGS);
#endif /* PROCSIGNAL_H */
|
