Semaphore
PHP Manual

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

如果成功则返回 TRUE,失败则返回 FALSE

参见


Semaphore
PHP Manual