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
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/*-------------------------------------------------------------------------
*
* ipc.h
* POSTGRES inter-process communication definitions.
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: ipc.h,v 1.54 2001/11/05 17:46:35 momjian Exp $
*
* Some files that would normally need to include only sys/ipc.h must
* instead include this file because on Ultrix, sys/ipc.h is not designed
* to be included multiple times. This file (by virtue of the ifndef IPC_H)
* is.
*-------------------------------------------------------------------------
*/
#ifndef IPC_H
#define IPC_H
#include <sys/types.h>
#ifdef HAVE_SYS_IPC_H
#include <sys/ipc.h>
#endif /* HAVE_SYS_IPC_H */
#ifndef HAVE_UNION_SEMUN
union semun
{
int val;
struct semid_ds *buf;
unsigned short *array;
};
#endif
/* generic IPC definitions */
#define IPCProtection (0600) /* access/modify by user only */
/* semaphore definitions */
typedef uint32 IpcSemaphoreKey; /* semaphore key passed to semget(2) */
typedef int IpcSemaphoreId; /* semaphore ID returned by semget(2) */
#define IPC_NMAXSEM 32 /* maximum number of semaphores per semID */
#define PGSemaMagic 537 /* must be less than SEMVMX */
/* shared memory definitions */
typedef uint32 IpcMemoryKey; /* shared memory key passed to shmget(2) */
typedef int IpcMemoryId; /* shared memory ID returned by shmget(2) */
typedef struct PGShmemHeader /* standard header for all Postgres shmem */
{
int32 magic; /* magic # to identify Postgres segments */
#define PGShmemMagic 679834892
pid_t creatorPID; /* PID of creating process */
uint32 totalsize; /* total size of segment */
uint32 freeoffset; /* offset to first free space */
} PGShmemHeader;
/* ipc.c */
extern bool proc_exit_inprogress;
extern void proc_exit(int code);
extern void shmem_exit(int code);
extern void on_proc_exit(void (*function) (), Datum arg);
extern void on_shmem_exit(void (*function) (), Datum arg);
extern void on_exit_reset(void);
extern void IpcInitKeyAssignment(int port);
extern IpcSemaphoreId IpcSemaphoreCreate(int numSems, int permission,
int semStartValue,
bool removeOnExit);
extern void IpcSemaphoreKill(IpcSemaphoreId semId);
extern void IpcSemaphoreLock(IpcSemaphoreId semId, int sem, bool interruptOK);
extern void IpcSemaphoreUnlock(IpcSemaphoreId semId, int sem);
extern bool IpcSemaphoreTryLock(IpcSemaphoreId semId, int sem);
extern int IpcSemaphoreGetValue(IpcSemaphoreId semId, int sem);
extern PGShmemHeader *IpcMemoryCreate(uint32 size, bool makePrivate,
int permission);
extern bool SharedMemoryIsInUse(IpcMemoryKey shmKey, IpcMemoryId shmId);
/* ipci.c */
extern void CreateSharedMemoryAndSemaphores(bool makePrivate,
int maxBackends);
#endif /* IPC_H */
|
