code: List<CommitTaskAction> getCommitActions(TaskTrackerStatus tts) {
      synchronized (lockObject) {
        List<CommitTaskAction> saveList = new ArrayList<CommitTaskAction>();
        List<TaskStatus> taskStatuses = tts.getTaskReports();
        if (taskStatuses != null) {
          for (TaskStatus taskStatus : taskStatuses) {
            if (taskStatus.getRunState() == TaskStatus.State.COMMIT_PENDING) {
              TaskAttemptID taskId = taskStatus.getTaskID();
              TaskInProgress tip = taskLookupTable.getTIP(taskId);
              if (tip == null) {
                continue;
              }
              if (tip.shouldCommit(taskId)) {
                CommitTaskAction commitAction = new CommitTaskAction(taskId);
                saveList.add(commitAction);
                LOG.debug(tts.getTrackerName() +
                    " -> CommitTaskAction: " + taskId);
              }
            }
          }
        }
        return saveList;
      }
    }
docs: A tracker wants to know if any of its Tasks can be committed
  @param tts The task tracker status
  @return The commit actions.