sem_get Get a semaphore id

sem_get

(PHP 4, PHP 5)

sem_get — Get a semaphore id

说明

resource sem_get ( int $key [, int $max_acquire = 1 [, int $perm = 0666 [, int $auto_release = 1 ]]] )

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.

参数

key
max_acquire: The number of processes that can acquire the semaphore simultaneously is set to max_acquire.
perm: The semaphore permissions. 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.