Question

I don’t understand what happening in my application. My app structure:

EventListActivity (List of events)
 EventDetailActivity (Detail of selected event and button to open list of persons)
  EventPersonsListActiviy (List of persons who connected to the event
   EventPersonDetialActivity  (Detail of selected person)

When I started the application I got this meminfo:

               native   dalvik    other  total      limit     bitmap  nativeBitmap
allocated:     5257     6620      N/A    11877      N/A       28      661

after the I go through the tree, and when I’m in EventPersonDetialActivity I got this

               native  dalvik    other  total      limit     bitmap  nativeBitmap
allocated:     5690     6740      N/A    12430      N/A       149      661

But when I’m open again the EventListActivity from the menu. But before start activity I close all latest activites (I have a HistoryManager, which is include a List, and when I open an activity I put into the list, and before start again the main activity I call finish() method to activities and after that clear a list. ) And in all activities in onDestroy a set all variable to null and call System.gc(). But I got this:

               native  dalvik    other  total      limit     bitmap  nativeBitmap
allocated:     5663    7193      N/A    12856      N/A       135      661

Why bigger the total memory usage in the third case than in the first case? While in the memory has only the EventListActivity?
And if I reply this method a lot, I got out of memory finally 🙁

Answer 1

Do this to figure it out:

1. Go to your EventListActivity a few times and check memory usage until it climbs up (but before it crashes).
2. Take a heap dump
3. Examine the heap dump using jhat
4. Look at all instances of all classes (except system)
5. At the top of the list you should see how many instances you have of each activity and other relevant classes. This should help you determine which objects aren’t being properly freed.
6. Figure out which objects are referencing the objects that you think should have been collected by the GC (by following the links to “objects referencing this object”)