Mutex cache backend WIP.

extensions/mutex/yii/mutex/cache/Mutex.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\mutex\cache;
+
+use Yii;
+use yii\base\InvalidConfigException;
+use yii\caching\Cache;
+use yii\caching\DbCache;
+use yii\caching\MemCache;
+
+/**
+ * @author resurtm <resurtm@gmail.com>
+ * @since 2.0
+ */
+class Mutex extends \yii\mutex\Mutex
+{
+	/**
+	 * @var Cache|string the cache object or the application component ID of the cache object.
+	 * The messages data will be cached using this cache object. Note, this property has meaning only
+	 * in case [[cachingDuration]] set to non-zero value.
+	 * After the Mutex object is created, if you want to change this property, you should only assign
+	 * it with a cache object.
+	 */
+	public $cache = 'cache';
+
+
+	/**
+	 * Initializes the DbMessageSource component. Configured [[cache]] component will be initialized.
+	 * @throws InvalidConfigException if [[cache]] is invalid.
+	 */
+	public function init()
+	{
+		parent::init();
+		if (is_string($this->cache)) {
+			$this->cache = Yii::$app->getComponent($this->cache);
+		}
+		if (!$this->cache instanceof Cache) {
+			throw new InvalidConfigException('Mutex::cache must be either a cache object or the application component ID of the cache object.');
+		}
+	}
+
+	/**
+	 * This method should be extended by concrete mutex implementations. Acquires lock by given name.
+	 * @param string $name of the lock to be acquired.
+	 * @param integer $timeout to wait for lock to become released.
+	 * @return boolean acquiring result.
+	 */
+	protected function acquire($name, $timeout = 0)
+	{
+
+	}
+
+	/**
+	 * This method should be extended by concrete mutex implementations. Releases lock by given name.
+	 * @param string $name of the lock to be released.
+	 * @return boolean release result.
+	 */
+	protected function release($name)
+	{
+		return $this->cache->delete("mutex.{$name}");
+	}
+
+	/**
+	 * This method may optionally be extended by concrete mutex implementations. Checks whether lock has been
+	 * already acquired by given name.
+	 * @param string $name of the lock to be released.
+	 * @return null|boolean whether lock has been already acquired. Returns `null` in case this feature
+	 * is not supported by concrete mutex implementation.
+	 */
+	protected function getIsAcquired($name)
+	{
+		
+	}
+
+	/**
+	 * This method should be extended by concrete mutex implementations. Returns whether current mutex
+	 * implementation can be used in a distributed environment.
+	 * @return boolean whether current mutex implementation can be used in a distributed environment.
+	 */
+	public function getIsDistributed()
+	{
+		return $this->cache instanceof DbCache || $this->cache instanceof MemCache;
+	}
+}