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/*
* Copyright (c) 1994, 1995. Netscape Communications Corporation. All
* rights reserved.
*
* Use of this software is governed by the terms of the license agreement for
* the Netscape Communications or Netscape Comemrce Server between the
* parties.
*/
/* ------------------------------------------------------------------------ */
/*
* sem.h: Attempt to provide multi-process semaphores across platforms
*
* Rob McCool
*/
#ifndef SEM_H
#define SEM_H
#include "systems.h"
/* All of the implementations currently use int as the semaphore type */
#ifdef SEM_WIN32
typedef HANDLE SEMAPHORE;
#define SEM_ERROR NULL
/* That oughta hold them (I hope) */
#define SEM_MAXVALUE 32767
#else /* ! SEM_WIN32 */
typedef int SEMAPHORE;
#define SEM_ERROR -1
#endif /* SEM_WIN32 */
/*
* sem_init creates a semaphore using the given name and unique
* identification number. filename should be a file accessible to the
* process. Returns SEM_ERROR on error.
*/
SEMAPHORE sem_init(char *name, int number);
/*
* sem_terminate de-allocates the given semaphore.
*/
void sem_terminate(SEMAPHORE id);
/*
* sem_grab attempts to gain exclusive access to the given semaphore. If
* it can't get it, the caller will block. Returns -1 on error.
*/
int sem_grab(SEMAPHORE id);
/*
* sem_release releases this process's exclusive control over the given
* semaphore. Returns -1 on error.
*/
int sem_release(SEMAPHORE id);
#endif
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