sem_get
Description
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
.
The semaphore is created if necessary using the permission bits specified in
perm
(defaults to 0666). The number of processes that can
acquire the semaphore simultaneously is set to max_acquire
(defaults to 1). Actually this value is set only if the process
finds it is the only process currently attached to the semaphore.
Optional parameter auto_release
specifies if the
semaphore should be automatically released on request shutdown.
It is available since PHP 4.3.0.
Returns a positive semaphore identifier on success, or FALSE on error.
A second call to sem_get() for the same key will return a different semaphore identifier, but both identifiers access the same underlying semaphore.
See also sem_acquire(), sem_release(), and ftok().