Android architecture for real-time applications

Question

I'm having some trouble achieving adequate real-time performance from my application and am wondering if I've architected it suboptimally. The requirement is for the application to play a sound and draw a line on a Canvas at a user specified time interval.

I have a Thread that sleeps for the user-specified time interval, wakes up and uses a Handler and Runnable to do the required drawing and sound playback. When I run the application, the beat is steady sometimes, but other times, you can see the effect of GC and random warning conditions from the AudioFlinger.

Is having a Timer thread post back to the GUI thread via Handler/Runnable the best approach? Is there something I can do to bump up the priority of my app while it is visible so that other apps and Android activity are less likely to interrupt it? Do I need to use the NDK to access real-time features not present in the Java API?

Answer 1

It sounds like what you want to have going is a game loop. There are many tutorials out there on creating game loops with more consistant timing that just sleeping, for example simple java android game loop. You might try searching based on that term, see if it helps.

Answer 2

Also when trying to create real time applications (as in constantly dynamic applications not scientific real time system) you would want to avoid to let the garbage collector run. This takes some time and can be perceived as lag. So don't create objects you need to dispose immediately etc.