xcache_get_for_update/xcache_lock/xcache_unlock (was Integrated locking system)

[Martyo]

I would like x-cache to introduce an integrated locking system. Take for example this inefficient locking method:

while(xcache_get("lock_test"))  { // check if lock exists
	usleep(10); // wait for 10ms
	$waittime += 10; // add wait time to variable
	if($waittime > 10000) { // check if we've been waiting for 10 seconds
		break;
	}
}
xcache_set("lock_test", true); // set the lock
$the_cache_test = xcache_get("test"); // load the test cache into PHP
array_push($the_cache_test, "a test"); // do some stuff here, change $the_cache_test
xcache_set("test", $the_cache_test);
xcache_set("lock_test", false); // unset the lock

Instead of this, I would suggest adding a locking value to xcache_get and xcache_set, like the following:

$new_method = xcache_get("test", true);
array_push($new_method, "the new method");
xcache_set("test", $new_method, false);

The "true" part in xcache_get sets the lock for "test". The "false" part in xcache_set sets the lock for "test" to false. If xcache_get is called and the lock is set, then xcache should sleep for 10ms and check again (this should be defined in the xcache PHP.ini settings)

[moo]

xcache_lock/xcache_unlock is also nice...