sem_acquire

(PHP 4, PHP 5, PHP 7)

sem_acquire — Acquire a semaphore

Description

sem_acquire() by default 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.

Parameters

sem_identifier

sem_identifier is a semaphore resource, obtained from sem_get().

nowait

Specifies if the process shouldn't wait for the semaphore to be acquired. If set to true, the call will return false immediately if a semaphore cannot be immediately acquired.

Return Values

Returns TRUE on success or FALSE on failure.

Changelog

See Also

• sem_get() - Get a semaphore id

• sem_release() - Release a semaphore

← msg_stat_queue

sem_get →

Licensed under the Creative Commons Attribution License v3.0 or later.

https://secure.php.net/manual/en/function.sem-acquire.php