class Lock

Lock.php

<?php

class Lock {
	
	private $mc;
	private $key;
	
	function __construct($key=null, $expire=300) {
		$this->mc = MemoryCache::getInstance($expire);
		$this->key = is_null($key)? "mv_lock_". rand(1000, 9999): $key;
	}
	
	
	function acquire() {
		if ($this->check()) {
			return null;
		}
		return $this->mc->set($this->key, true);
	}
	
	
	function release() {
		return $this->mc->delete($this->key);
	}
	
	
	function check() {
		if (!Net::isControlF5() and (($result = $this->mc->get($this->key)) !== false)) {
			throw new LockedException("LOCKED");
		}
		return $result;
	}
}

Esta clase tiene dependencias como el MemoryCache.php, Net.php o el CustomException.php