wikimedia / mediawiki

	 * @param int $timeout

	 * @return bool

	 */

	public function lock( $lockName, $method, $timeout = 5 ) {

		$encName = $this->addQuotes( $this->makeLockName( $lockName ) );

		$result = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method );

		$row = $this->fetchObject( $result );

		if ( $row->lockstatus == 1 ) {

			parent::lock( $lockName, $method, $timeout ); // record

			return true;

		}

		$this->queryLogger->warning( __METHOD__ . " failed to acquire lock '$lockName'\n" );

		return false;

	}

	/**

	 * FROM MYSQL DOCS:

	 * @param string $method

	 * @return bool

	 */

	public function unlock( $lockName, $method ) {

		$encName = $this->addQuotes( $this->makeLockName( $lockName ) );

		$result = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method );

		$row = $this->fetchObject( $result );

		if ( $row->lockstatus == 1 ) {

			parent::unlock( $lockName, $method ); // record

			return true;

		}

		$this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );

		return false;

	}

	private function makeLockName( $lockName ) {

		// http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock