code: protected function releaseLock($name)
      {
          if (!isset($this->_files[$name])) {
              return false;
          }
  
          if ($this->isWindows) {
              // Under windows it's not possible to delete a file opened via fopen (either by own or other process).
              // That's why we must first unlock and close the handle and then *try* to delete the lock file.
              flock($this->_files[$name], LOCK_UN);
              fclose($this->_files[$name]);
              @unlink($this->getLockFilePath($name));
          } else {
              // Under unix it's possible to delete a file opened via fopen (either by own or other process).
              // That's why we must unlink (the currently locked) lock file first and then unlock and close the handle.
              unlink($this->getLockFilePath($name));
              flock($this->_files[$name], LOCK_UN);
              fclose($this->_files[$name]);
          }
  
          unset($this->_files[$name]);
          return true;
      }
docs: Releases lock by given name.
  @param string $name of the lock to be released.
  @return bool release result.