FirebaseJobDispatcher: When is JobService.onStopJob() called

Question

I've seen questions on the matter. Checked out the source code but still can't figure out why JobService.onStopJob() is not called, after a job was done.

Code which constructs the Job:

private Job jobFrom(Bundle bundle, int windowStart, int windowEnd) {
   return dispatcher.newJobBuilder()
      .setService(AttackJobService.class)
      .setTag(attack.getPushId())
      .setRecurring(false)
      .setLifetime(Lifetime.UNTIL_NEXT_BOOT)
      .setTrigger(Trigger.executionWindow(windowStart, windowEnd))
      .setReplaceCurrent(false)
      .setExtras(bundle)
      .build();
}

A job is scheduled like bellow:

FirebaseJobDispatcher dispatcher = new FirebaseJobDispatcher(new GooglePlayDriver(context));
dispatcher.mustSchedule(job);

My JobService is still quite simple, because I am still trying to test the framework:

public boolean onStartJob(@NonNull JobParameters job) {
    new Thread(() -> {
        try {
            Thread.sleep(2000);
            jobFinished(job,false); //signal that the job is done
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }).start();
    return true; // Answers to the question: "Is there still work going on?"
}

public boolean onStopJob(@NonNull JobParameters job) {
    Log.d(TAG, "onStopJob() called");
    return false; // Answers to the question: "Should this job be retried?"
}

The onStartJob() is getting called and the thread starts executing. The thread is sleeping for 2 seconds and then jobFinished() is called.

Doesn't that means that onStopJob() should be called too?

Answer 1

If you read the Source code for public abstract class JobService extends Service {, you can read all about when it's called:

/**
   * Called when the scheduling engine has decided to interrupt the execution of a running job, most
   * likely because the runtime constraints associated with the job are no longer satisfied. The job
   * must stop execution.
   *
   * @return true if the job should be retried
   * @see com.firebase.jobdispatcher.JobInvocation.Builder#setRetryStrategy(RetryStrategy)
   * @see RetryStrategy
   */
  @MainThread
  public abstract boolean onStopJob(JobParameters job);

This is not an onJobStopped kinda callback, like an animation onComplete, this is a "hey, you must stop" kinda call.