sem_get
(PHP 4, PHP 5)
sem_get — Get a semaphore id
说明
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 (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.
返回值
Returns a positive semaphore identifier on success, or FALSE on error.
更新日志
| 版本 | 说明 |
|---|---|
| 4.3.0 | The auto_release parameter was added. |
