Debugging on Android

ISA 673, OS Security

Rahul Murmuria

Goal of this tutorial

Quick pointers on how to start debugging an Android application
Getting to know DDMS
Placing the breakpoints at the right points
Working with Eclipse and alternatives
Working with different screen sizes

Starting to Debug

See guide/tutorials/hello-world.html#debugging

Starting to Debug

Right-Click on the Project and choose 'Debug As' Android Application
Will prompt for creating "Run configuration" when doing this first time
See guide/developing/eclipse-adt.html#RunConfig
Tools you can look at: DDMS, Traceview, logcat, Dev Tools
See guide/developing/debug-tasks.html

Getting to know DDMS

Standalone or as a perspective within Eclipse
Shows logcat messages (V), (E), (I): verbose, error and info
Devices panel has list of all devices with processes having debgging=true set
pid and forward ports listed for every process, so that they can be monitored remotely

Getting to know DDMS

Log.v("Creating database done.");
Log.e("Error reading sql file " + e.getMessage(), e);
Log.i("ProcessMonitor", "No_of_records_read: "+ sys_proc.size());

Placing Breakpoints

Setting the breakpoint at the start of the 'main screen'... here, in Class "NotesList" find onCreate()
AndroidManifest.xml :-

<activity android:name="NotesList" android:label="@string/title_notes_list"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity>

Placing Breakpoints

When application hits that code, debugger stops it there
On Eclipse this will take you to 'debug perspective'

Eclipse Debug Perspective

Breakpoints view, source editor for stepping through the code, threads and call stack, etc.

Eclipse Alternatives

omappedia.org/wiki/Android_Debugging
# jdb -attach localhost:8610
See java.sun.com/j2se/1.3/docs/tooldocs/solaris/jdb.html
Specially useful if we need to monitor processes remotely
Correct port number can be got from DDMS or from 'adb shell'
See guide/developing/debug-tasks.html#ide-debug-port

Eclipse Alternatives

Profiling

Read about Application performance profiling and 'traceview' at guide/developing/tools/traceview.html

Emacs as an IDE

Also, a complete build environment for the Emacs fanatics as a almost equivalent Eclipse alternative

Different Screen sizes

Under 'targets' tab, or using the avd, 4 different emulators are available
HVGA-L, HVGA-P, QVGA-L, QVGA-P

Experiment at will!

Questions?