(PECL sync >= 1.0.0)
SyncMutex::lock — Waits for an exclusive lock
Obtains an exclusive lock on a SyncMutex object. If the lock is already acquired, then this increments an internal counter.
The number of milliseconds to wait for the exclusive lock. A value of -1 is infinite.
A boolean of TRUE if the lock was obtained, FALSE otherwise.
Example #1 SyncMutex::lock() example
$mutex = new SyncMutex("UniqueName");
echo "Unable to lock mutex.";
/* ... */