android - How to fix problem with DeadObjectException?

Question

I have successfully finished an Android project's implementation and started to test the app for memory leaks.

Sometimes, I get DeadObjectExceptionafter a long trip in the app and all of the memory allocations are freed.

How can I detect this problem?

I have made some research about DDMS tools to detect memory leaks, Due to I have no idea about DeadObjectExeption, I don't know where to start.

Answer 1

This is not a memory leak problem. Definition of the memory leak (from Wikipedia):

A memory leak, in computer science (or leakage, in this context), occurs when a computer program acquires memory but fails to release it back to the operating system.

Here, you have an opposite case - memory is freed before it should (at least from your program's point of view).

From developer.android.com:

DeadObjectException extends RemoteException

The object you are calling has died, because its hosting process no longer exists.

For example:

You have the classes MyActivity and MyService. You use Handler/Messenger to communicate between them.

You create Handler and Messenger in MyActivity, and then send created instance of Messenger to MyService via an Intent. Then you do some stuff, time passes, and your MyActivity gets destroyed, together with it's Handler and Messenger. Now, if you don't handle that well, MyService won't know that Messenger that he has is not valid any more, so, he tries to send something through it, and get DeadObjectexception:

/* Send a Message to this Messenger's Handler.

Parameters:

message The Message to send. Usually retrieved through Message.obtain().

Throws:

RemoteException Throws DeadObjectException if the target Handler no longer exists.*/

public void send(Message message) throws RemoteException {...}