protected synchronized void doShutDown()

in twill-yarn/src/main/java/org/apache/twill/yarn/YarnTwillController.java [137:185]
38 lines of code
7 McCabe index (conditional complexity)

  protected synchronized void doShutDown() {
    if (processController == null) {
      LOG.warn("No process controller for application that is not submitted.");
      return;
    }

    // Stop polling if it is running.
    stopPollStatus();

    // Wait for the stop message being processed
    try {
      Uninterruptibles.getUninterruptibly(getStopMessageFuture(),
                                          Constants.APPLICATION_MAX_STOP_SECONDS, TimeUnit.SECONDS);
    } catch (Exception e) {
      LOG.error("Failed to wait for stop message being processed.", e);
      // Kill the application through yarn
      kill();
    }

    // Poll application status from yarn
    try {
      Stopwatch stopWatch = new Stopwatch();
      stopWatch.start();
      long maxTime = TimeUnit.MILLISECONDS.convert(Constants.APPLICATION_MAX_STOP_SECONDS, TimeUnit.SECONDS);

      YarnApplicationReport report = processController.getReport();
      FinalApplicationStatus finalStatus = report.getFinalApplicationStatus();
      ApplicationId appId = report.getApplicationId();
      while (finalStatus == FinalApplicationStatus.UNDEFINED &&
          stopWatch.elapsedTime(TimeUnit.MILLISECONDS) < maxTime) {
        LOG.debug("Yarn application final status for {} {}: {}", appName, appId, finalStatus);
        TimeUnit.SECONDS.sleep(1);
        stopWatch.reset();
        stopWatch.start();
        finalStatus = processController.getReport().getFinalApplicationStatus();
      }
      LOG.debug("Yarn application {} {} completed with status {}", appName, appId, finalStatus);

      // Application not finished after max stop time, kill the application
      if (finalStatus == FinalApplicationStatus.UNDEFINED) {
        kill();
      }
    } catch (Exception e) {
      LOG.warn("Exception while waiting for application report: {}", e.getMessage(), e);
      kill();
    }

    super.doShutDown();
  }