[Android] Memory Leak

1. Trace Memory Allocation
   http://developer.android.com/resources/articles/track-mem.html
2. Trace Memory Leak in Native Code
   
   • http://discuz-android.blogspot.com/
     Key words:
     Automatic Memory Leak Tracking on Android
     android memory usage with hprof
     
3. Avoid Memory Leak
   http://developer.android.com/resources/articles/avoiding-memory-leaks.html
4. Common Memory Leak
1. Don't release field of Activity
   When activity is closed with calling finish(), the finalize() method may not be called, the instance may stay in memory for re-use in future, but if memory is low, the activity will be released. So don't excpet GC to release field of Activity subclass, you must release them explicitly in onDestroy method. ie.
   public void onDestroy()
   {
       super.onDestroy();
       m_textField = null;
       m_hashTable.clare();
       m_hashTable = null;
   }
   
2. Send messages in a wrong way
   Correct:
   Message message = handler.obtainMessage(); //handler is an instance of type Handler
   //Set fields of message
   message.id = xxx
   message.obj = xxx
   ...
   message.sendToTarget();
   Wrong:
   Message message = new Message();
   message.id = xxx
   message.obj = xxx
   ...
   handler.sendMessage(message);
   
3. That forget to call close() method may cause memory leak
   
   • Cursor
   • IO Stream, such as InputStream/FileInputStream, OutputStream/FileOutputStream
   • Socket
   • Database
     
4. That forget to call clear() may cause memory leak
   
   • HashTable
   • Map and its subclass,
     
   • Collection and its subclass, such as List, ArrayList, LinkedList, Vector, Set, Stack, Queue,
     
5. ...
   
5. ...