sem_acquire
(PHP 4, PHP 5, PHP 7)
sem_acquire — Acquire a semaphore
Description
sem_acquire ( SysvSemaphore $semaphore [, bool $non_blocking = false ] ) : bool
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
-
semaphore -
semaphoreis a semaphore obtained from sem_get(). -
non_blocking -
Specifies if the process shouldn't wait for the semaphore to be acquired. If set to
true, the call will returnfalseimmediately if a semaphore cannot be immediately acquired.
Return Values
Returns true on success or false on failure.
Changelog
| Version | Description |
|---|---|
| 8.0.0 | semaphore expects a SysvSemaphore instance now; previously, a resource was expected. |
See Also
- sem_get() - Get a semaphore id
- sem_release() - Release a semaphore
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.sem-acquire.php