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procsignal.h
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1 /*-------------------------------------------------------------------------
2  *
3  * procsignal.h
4  * Routines for interprocess signaling
5  *
6  *
7  * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/storage/procsignal.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef PROCSIGNAL_H
15 #define PROCSIGNAL_H
16 
17 #include "storage/backendid.h"
18 
19 
20 /*
21  * Reasons for signaling a Postgres child process (a backend or an auxiliary
22  * process, like checkpointer). We can cope with concurrent signals for different
23  * reasons. However, if the same reason is signaled multiple times in quick
24  * succession, the process is likely to observe only one notification of it.
25  * This is okay for the present uses.
26  *
27  * Also, because of race conditions, it's important that all the signals be
28  * defined so that no harm is done if a process mistakenly receives one.
29  */
30 typedef enum
31 {
32  PROCSIG_CATCHUP_INTERRUPT, /* sinval catchup interrupt */
33  PROCSIG_NOTIFY_INTERRUPT, /* listen/notify interrupt */
34  PROCSIG_PARALLEL_MESSAGE, /* message from cooperating parallel backend */
35  PROCSIG_WALSND_INIT_STOPPING, /* ask walsenders to prepare for shutdown */
36  PROCSIG_BARRIER, /* global barrier interrupt */
37  PROCSIG_LOG_MEMORY_CONTEXT, /* ask backend to log the memory contexts */
38 
39  /* Recovery conflict reasons */
46 
47  NUM_PROCSIGNALS /* Must be last! */
49 
50 typedef enum
51 {
52  PROCSIGNAL_BARRIER_SMGRRELEASE /* ask smgr to close files */
54 
55 /*
56  * prototypes for functions in procsignal.c
57  */
58 extern Size ProcSignalShmemSize(void);
59 extern void ProcSignalShmemInit(void);
60 
61 extern void ProcSignalInit(int pss_idx);
62 extern int SendProcSignal(pid_t pid, ProcSignalReason reason,
63  BackendId backendId);
64 
66 extern void WaitForProcSignalBarrier(uint64 generation);
67 extern void ProcessProcSignalBarrier(void);
68 
70 
71 #endif /* PROCSIGNAL_H */
int BackendId
Definition: backendid.h:21
#define SIGNAL_ARGS
Definition: c.h:1355
size_t Size
Definition: c.h:540
ProcSignalReason
Definition: procsignal.h:31
@ PROCSIG_PARALLEL_MESSAGE
Definition: procsignal.h:34
@ PROCSIG_RECOVERY_CONFLICT_BUFFERPIN
Definition: procsignal.h:44
@ PROCSIG_CATCHUP_INTERRUPT
Definition: procsignal.h:32
@ PROCSIG_RECOVERY_CONFLICT_LOCK
Definition: procsignal.h:42
@ PROCSIG_LOG_MEMORY_CONTEXT
Definition: procsignal.h:37
@ PROCSIG_BARRIER
Definition: procsignal.h:36
@ PROCSIG_RECOVERY_CONFLICT_DATABASE
Definition: procsignal.h:40
@ PROCSIG_WALSND_INIT_STOPPING
Definition: procsignal.h:35
@ PROCSIG_RECOVERY_CONFLICT_SNAPSHOT
Definition: procsignal.h:43
@ PROCSIG_NOTIFY_INTERRUPT
Definition: procsignal.h:33
@ PROCSIG_RECOVERY_CONFLICT_TABLESPACE
Definition: procsignal.h:41
@ NUM_PROCSIGNALS
Definition: procsignal.h:47
@ PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK
Definition: procsignal.h:45
void ProcSignalShmemInit(void)
Definition: procsignal.c:125
void ProcessProcSignalBarrier(void)
Definition: procsignal.c:467
ProcSignalBarrierType
Definition: procsignal.h:51
@ PROCSIGNAL_BARRIER_SMGRRELEASE
Definition: procsignal.h:52
void WaitForProcSignalBarrier(uint64 generation)
Definition: procsignal.c:392
int SendProcSignal(pid_t pid, ProcSignalReason reason, BackendId backendId)
Definition: procsignal.c:261
void ProcSignalInit(int pss_idx)
Definition: procsignal.c:161
uint64 EmitProcSignalBarrier(ProcSignalBarrierType type)
Definition: procsignal.c:332
Size ProcSignalShmemSize(void)
Definition: procsignal.c:111
void procsignal_sigusr1_handler(SIGNAL_ARGS)
Definition: procsignal.c:638