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/*-------------------------------------------------------------------------
*
* 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 1.49 2001/03/22 04:01:05 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 /* 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;
/* spinlock definitions */
typedef enum _LockId_
{
BUFMGRLOCKID,
OIDGENLOCKID,
XIDGENLOCKID,
CNTLFILELOCKID,
SHMEMLOCKID,
SHMEMINDEXLOCKID,
LOCKMGRLOCKID,
SINVALLOCKID,
PROCSTRUCTLOCKID,
#ifdef STABLE_MEMORY_STORAGE
MMCACHELOCKID,
#endif
MAX_SPINS /* must be last item! */
} _LockId_;
/* 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 */
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