zos-semaphore.h

Go to the documentation of this file.

 
// Licensed Materials - Property of IBM
// ZOSLIB
// (C) Copyright IBM Corp. 2020. All Rights Reserved.
// US Government Users Restricted Rights - Use, duplication
// or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
 
// APIs that implement POSIX semaphores.
 
#ifndef ZOS_SEMAPHORE_H_
#define ZOS_SEMAPHORE_H_
 
#include "zos-macros.h"
 
#include <errno.h>
#include <inttypes.h>
#include <pthread.h>
#include <sys/sem.h>
 
#if __WORDSIZE == 64
#define __SIZEOF_SEM_T 32
#else
#define __SIZEOF_SEM_T 16
#endif
 
#define SEM_FAILED ((sem_t *)0)
 
typedef struct __sem {
  volatile unsigned int value;
  volatile unsigned int id; // 0 for non shared (thread), pid for share
  volatile unsigned int waitcnt;
  pthread_mutex_t mutex;
  pthread_cond_t cond;
} ____sem_t;
 
typedef struct {
  ____sem_t *_s;
} __sem_t;
 
#define sem_t         __sem_t
 
#define sem_init      __sem_init
#define sem_post      __sem_post
#define sem_trywait   __sem_trywait
#define sem_timedwait __sem_timedwait
#define sem_wait      __sem_wait
#define sem_getvalue  __sem_getvalue
#define sem_destroy   __sem_destroy
 
#ifdef __cplusplus
extern "C" {
#endif
 
__Z_EXPORT int __sem_init(__sem_t *s0, int shared, unsigned int val);
__Z_EXPORT int __sem_post(__sem_t *s0);
__Z_EXPORT int __sem_trywait(__sem_t *s0);
__Z_EXPORT int __sem_timedwait(__sem_t *s0, const struct timespec *abs_timeout);
__Z_EXPORT int __sem_wait(__sem_t *s0);
__Z_EXPORT int __sem_getvalue(__sem_t *s0, int *sval);
__Z_EXPORT int __sem_destroy(__sem_t *s0);
 
__Z_EXPORT unsigned int atomic_dec(volatile unsigned int *loc);
__Z_EXPORT unsigned int atomic_inc(volatile unsigned int *loc);
 
#ifdef __cplusplus
}
#endif
 
#endif // ZOS_SEMAPHORE_H_