120 static int os_createmutex(int *semid);
121 static void os_obtainmutex(int semid);
122 static void os_releasemutex(int semid);
123 static void os_destroymutex(int semid);
334 static int os_createmutex(int *semid) {  in os_createmutex()  argument
338 	if (semid == NULL) {  in os_createmutex()
347 	*semid = retVal; /* save key of created semaphore */  in os_createmutex()
349 	retVal = semctl(*semid, 0, SETVAL, sem_union);  in os_createmutex()
358 os_obtainmutex(int semid)  in os_obtainmutex()  argument
365 	(void) semop(semid, &sem_b, 1);  in os_obtainmutex()
369 os_releasemutex(int semid)  in os_releasemutex()  argument
376 	(void) semop(semid, &sem_b, 1);  in os_releasemutex()
381 os_destroymutex(int semid)  in os_destroymutex()  argument
385 	(void) semctl(semid, 0, IPC_RMID, sem_union);  in os_destroymutex()