sem_release
(PHP 4, PHP 5, PHP 7)
sem_release — Release a semaphore
说明
sem_release
( resource
$sem_identifier
) : boolsem_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.
返回值
成功时返回 TRUE， 或者在失败时返回 FALSE。