JobTracker.java

synchronized (JobTracker.this) {
  synchronized (jobs) {
    synchronized (taskScheduler) {
      for (JobInProgress job: retiredJobs) {
        removeJobTasks(job);
        jobs.remove(job.getProfile().getJobID());
        for (JobInProgressListener l : jobInProgressListeners) {
          l.jobRemoved(job);
        }
        String jobUser = job.getProfile().getUser();
        synchronized (userToJobsMap) {
          ArrayList<JobInProgress> userJobs = userToJobsMap.get(jobUser);
          synchronized (userJobs) {
            userJobs.remove(job);
          }
          if (userJobs.isEmpty()) {
            userToJobsMap.remove(jobUser);
          }
        }
      }
    }
  }
}