App seems to stop working when the screen goes to sleep

Question

I have a CPU intensive long-running operation (a few hours) that I am using AsyncTask to perform. As it continues, it updates a progressbar on the screen to show what percen

Answer 1

Not sure if anyone will read this as the OP is several years old but I am in the same boat in that I need to use a wakelock for an app for internal use, and leaving the screen on was not ok (I just needed the cpu on so I could run some metrics queries) I simply used a partial wakelock; ie:

public class my_frag extends Fragment {
    WakeLock wl; 


    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    setRetainInstance(true);        
    PowerManager pm = (PowerManager) this.getActivity().getSystemService(Context.POWER_SERVICE);
    wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakeLock");  

    //I happen to have it in a button click event based on an async task 
    //Side note: I should probably be using a Loader for my Async task but this works fine 
    connectButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if (metrics_task != null)
            {
            Status s = metrics_task.getStatus();
            if (s.name().equals("RUNNING")){
                if (metrics_task.running){
                metrics_task.cancel(true);
                connectButton.setText("Start");
                metrics_task.running = false;
                wl.release(); <--releases it on async stop
                }
                else{
                    metrics_task = new start_metrics(ae);
                    metrics_task.execute();
                    wl.acquire(); <--starts it on async start
                }
            }
            else{

                metrics_task = new start_metrics(ae);
                metrics_task.execute();

            }
            }
            else{
                metrics_task = new start_metrics(ae);
                metrics_task.execute();
            }
        }
    });

This worked great with no issues