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sem_get

Get a semaphore id (PHP 4, PHP 5)
resource sem_get ( int key [, int max_acquire [, int perm [, int auto_release]]] )

sem_get() returns an id that can be used to access the System V semaphore with the given key.

A second call to sem_get() for the same key will return a different semaphore identifier, but both identifiers access the same underlying semaphore.

Parameters

key
max_acquire

The number of processes that can acquire the semaphore simultaneously is set to max_acquire (defaults to 1).

perm

The semaphore permissions. Defaults to 0666. Actually this value is set only if the process finds it is the only process currently attached to the semaphore.

auto_release

Specifies if the semaphore should be automatically released on request shutdown.

Return Values

Returns a positive semaphore identifier on success, or FALSE on error.

ChangeLog

VersionDescription
4.3.0 The auto_release parameter was added.