sem_acquire
sem_acquire
(PHP 4, PHP 5, PHP 7)
sem_acquire — Acquire a semaphore
Description
bool sem_acquire ( resource $sem_identifier [, bool $nowait = false ] )
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
| Version | Description |
|---|---|
| 5.6.1 | The $nowait parameter was added. |
See Also
- sem_get() - Get a semaphore id
- sem_release() - Release a semaphore
← msg_stat_queue
sem_get →
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Licensed under the Creative Commons Attribution License v3.0 or later.
