<?php /** * @link http://www.yiiframework.com/ * @copyright Copyright (c) 2008 Yii Software LLC * @license http://www.yiiframework.com/license/ */ namespace yii\mutex; use Yii; use yii\base\InvalidConfigException; use yii\helpers\FileHelper; /** * FileMutex implements mutex "lock" mechanism via local file system files. * This component relies on PHP `flock()` function. * * Application configuration example: * * ``` * [ * 'components' => [ * 'mutex' => [ * 'class' => 'yii\mutex\FileMutex' * ], * ], * ] * ``` * * Note: this component can maintain the locks only for the single web server, * it probably will not suffice to your in case you are using cloud server solution. * * Warning: due to `flock()` function nature this component is unreliable when * using a multithreaded server API like ISAPI. * * @see Mutex * * @author resurtm <resurtm@gmail.com> * @since 2.0 */ class FileMutex extends Mutex { /** * @var string the directory to store mutex files. You may use path alias here. * Defaults to the "mutex" subdirectory under the application runtime path. */ public $mutexPath = '@runtime/mutex'; /** * @var int the permission to be set for newly created mutex files. * This value will be used by PHP chmod() function. No umask will be applied. * If not set, the permission will be determined by the current environment. */ public $fileMode; /** * @var int the permission to be set for newly created directories. * This value will be used by PHP chmod() function. No umask will be applied. * Defaults to 0775, meaning the directory is read-writable by owner and group, * but read-only for other users. */ public $dirMode = 0775; /** * @var resource[] stores all opened lock files. Keys are lock names and values are file handles. */ private $_files = []; /** * Initializes mutex component implementation dedicated for UNIX, GNU/Linux, Mac OS X, and other UNIX-like * operating systems. * @throws InvalidConfigException */ public function init() { $this->mutexPath = Yii::getAlias($this->mutexPath); if (!is_dir($this->mutexPath)) { FileHelper::createDirectory($this->mutexPath, $this->dirMode, true); } } /** * Acquires lock by given name. * @param string $name of the lock to be acquired. * @param int $timeout to wait for lock to become released. * @return bool acquiring result. */ protected function acquireLock($name, $timeout = 0) { $file = fopen($this->getLockFilePath($name), 'w+'); if ($file === false) { return false; } if ($this->fileMode !== null) { @chmod($this->getLockFilePath($name), $this->fileMode); } $waitTime = 0; while (!flock($file, LOCK_EX | LOCK_NB)) { $waitTime++; if ($waitTime > $timeout) { fclose($file); return false; } sleep(1); } $this->_files[$name] = $file; return true; } /** * Releases lock by given name. * @param string $name of the lock to be released. * @return bool release result. */ protected function releaseLock($name) { if (!isset($this->_files[$name]) || !flock($this->_files[$name], LOCK_UN)) { return false; } else { fclose($this->_files[$name]); unlink($this->getLockFilePath($name)); unset($this->_files[$name]); return true; } } /** * Generate path for lock file. * @param string $name * @return string * @since 2.0.10 */ protected function getLockFilePath($name) { return $this->mutexPath . DIRECTORY_SEPARATOR . md5($name) . '.lock'; } }