wikimedia / mediawiki

	 * @return bool

	 * @since 1.20

	 */

	public function lockIsFree( $lockName, $method ) {

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

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

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

		return ( $row->lockstatus == 1 );

	}

	/**

	 * @param string $lockName

	 * @return bool

	 * @since 1.20

	 */

	public function lockIsFree( $lockName, $method ) {

		$key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );

		$result = $this->query( "SELECT (CASE(pg_try_advisory_lock($key))

			WHEN 'f' THEN 'f' ELSE pg_advisory_unlock($key) END) AS lockstatus", $method );

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

		return ( $row->lockstatus === 't' );

	}

	/**

	 * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS