SEM_ACQUIRE(3) 1 SEM_ACQUIRE(3) sem_acquire - Acquire a semaphoreSYNOPSISbool sem_acquire (resource $sem_identifier)DESCRIPTIONsem_acquire(3) blocks (if necessary) until the semaphore can be acquired. A process attempting to acquire a semaphore which it has already acquired will block forever if acquiring the semaphore would cause its maximum number of semaphore to be exceeded. After processing a request, any semaphores acquired by the process but not explicitly released will be released automatically and a warn- ing will be generated.PARAMETERSo $sem_identifier -$sem_identifier is a semaphore resource, obtained from sem_get(3).RETURN VALUESReturns TRUE on success or FALSE on failure.SEE ALSOsem_get(3), sem_release(3). PHP Documentation Group SEM_ACQUIRE(3)