| Server IP : 85.214.239.14 / Your IP : 18.221.221.171 Web Server : Apache/2.4.62 (Debian) System : Linux h2886529.stratoserver.net 4.9.0 #1 SMP Tue Jan 9 19:45:01 MSK 2024 x86_64 User : www-data ( 33) PHP Version : 7.4.18 Disable Function : pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_get_handler,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,pcntl_async_signals,pcntl_unshare, MySQL : OFF | cURL : OFF | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : OFF Directory : /usr/include/postgresql/9.6/server/storage/ |
Upload File : |
/*-------------------------------------------------------------------------
*
* pg_sema.h
* Platform-independent API for semaphores.
*
* PostgreSQL requires counting semaphores (the kind that keep track of
* multiple unlock operations, and will allow an equal number of subsequent
* lock operations before blocking). The underlying implementation is
* not the same on every platform. This file defines the API that must
* be provided by each port.
*
*
* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/storage/pg_sema.h
*
*-------------------------------------------------------------------------
*/
#ifndef PG_SEMA_H
#define PG_SEMA_H
/*
* PGSemaphoreData and pointer type PGSemaphore are the data structure
* representing an individual semaphore. The contents of PGSemaphoreData
* vary across implementations and must never be touched by platform-
* independent code. PGSemaphoreData structures are always allocated
* in shared memory (to support implementations where the data changes during
* lock/unlock).
*
* pg_config.h must define exactly one of the USE_xxx_SEMAPHORES symbols.
*/
#ifdef USE_NAMED_POSIX_SEMAPHORES
#include <semaphore.h>
typedef sem_t *PGSemaphoreData;
#endif
#ifdef USE_UNNAMED_POSIX_SEMAPHORES
#include <semaphore.h>
typedef sem_t PGSemaphoreData;
#endif
#ifdef USE_SYSV_SEMAPHORES
typedef struct PGSemaphoreData
{
int semId; /* semaphore set identifier */
int semNum; /* semaphore number within set */
} PGSemaphoreData;
#endif
#ifdef USE_WIN32_SEMAPHORES
typedef HANDLE PGSemaphoreData;
#endif
typedef PGSemaphoreData *PGSemaphore;
/* Module initialization (called during postmaster start or shmem reinit) */
extern void PGReserveSemaphores(int maxSemas, int port);
/* Initialize a PGSemaphore structure to represent a sema with count 1 */
extern void PGSemaphoreCreate(PGSemaphore sema);
/* Reset a previously-initialized PGSemaphore to have count 0 */
extern void PGSemaphoreReset(PGSemaphore sema);
/* Lock a semaphore (decrement count), blocking if count would be < 0 */
extern void PGSemaphoreLock(PGSemaphore sema);
/* Unlock a semaphore (increment count) */
extern void PGSemaphoreUnlock(PGSemaphore sema);
/* Lock a semaphore only if able to do so without blocking */
extern bool PGSemaphoreTryLock(PGSemaphore sema);
#endif /* PG_SEMA_H */