(PHP 4, PHP 5, PHP 7)
sem_release — Release a semaphore
$sem_identifier) : bool
sem_release() releases the semaphore if it is currently acquired by the calling process, otherwise a warning is generated.
After releasing the semaphore, sem_acquire() may be called to re-acquire it.
A Semaphore resource handle as returned by sem_get().
TRUE on success or
FALSE on failure.