sem_acquire
(PHP 4, PHP 5, PHP 7, PHP 8)
sem_acquire — Acquire a semaphore
说明
$semaphore
, bool $non_blocking
= false
) : boolsem_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.
参数
-
semaphore
-
semaphore
is 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 returnfalse
immediately if a semaphore cannot be immediately acquired.
返回值
成功时返回 true
, 或者在失败时返回 false
。
更新日志
版本 | 说明 |
---|---|
8.0.0 |
semaphore expects a SysvSemaphore
instance now; previously, a resource was expected.
|