Profiling an Android application tutorial

I'm spending some spare time on an Android Reversi game which could need some performance tuning. After figuring out how the tooling works for Android profiling it works like a charm.

There are two ways to profile an application, using the debugging server DDMS or manually decide which parts of the code base are interesting for inspection. DDMS could be useful if you are inspecting code you might not be able to recompile. DDMS can also be used to inspect memory usage and more.

The easiest approach however is to use the debug interface provided by the Android API in your sources to specify when to start generating profiling information and when to end.

public int[] alphabeta(Board b, int maxDepth, long maxTime) {
      
      Debug.startMethodTracing("othello_profiling");

      // Here goes code to profile
  
      Debug.stopMethodTracing();
      return result;
   }

Run your program and you'll see in the VM logs when the profiler kicks in. (As usual the performance of your app in the emulator will sink to the bottom when profiling is enabled)

Now you got your profiling info written to the SD card of your Android emulator device. If you run into permission issues when writing to the SD card, add something like this to your Android Manifest.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />     

To fetch the file to your development computer use the adb tool that comes with the Android SDK. On my Windows machine I did something like this.


C:\Program Files (x86)\Android\android-sdk\platform-tools>adb pull /sdcard/othello_profiling.trace c:\temp\othello_profiling.trace
126 KB/s (2266911 bytes in 17.491s)


The tool traceview can interprete the file.

C:\Program Files (x86)\Android\android-sdk\tools>traceview.bat c:\Temp\othello_profiling.trace


Voila! You get a profiling view similar to what you get from common profilers like JProfiler, hprof etcetera. Here you can see each methods execution time and which parents and children methods it has connection to and much more.

Theres more you can do with the trace file. Traceview can also show you each threads exectution and calls in chronological order. You can simple zoom in on the interesting parts.

You may also want to try the tool dmtracdedump to create graphs over your call stack. See the Android documentation for more information.