sem_acquire
(PHP 4, PHP 5)
sem_acquire — Acquire a semaphore
说明
bool sem_acquire ( resource $sem_identifier )sem_acquire() 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 warning will be generated.
参数
- sem_identifier
-
sem_identifier is a semaphore resource, obtained from sem_get().
返回值
成功时返回 TRUE， 或者在失败时返回 FALSE.
参见
- sem_get() - Get a semaphore id
- sem_release() - Release a semaphore
