(PECL sync >= 1.0.0)
SyncMutex::unlock — Unlocks the mutex
$all = false): boolDecreases the internal counter of a SyncMutex object. When the internal counter reaches zero, the actual lock on the object is released.
allSpecifies whether or not to set the internal counter to zero and therefore release the lock.
成功時返回 true， 或者在失敗時返回 false。
示例 #1 SyncMutex::unlock() example
<?php
$mutex = new SyncMutex("UniqueName");
$mutex->lock();
/* ... */
$mutex->unlock();
?>