Memory Management in Android

Question

So, I tested my game out for the first time with the Monkey test. I managed to go about 3 minutes without a crash, but I ended up crashing with an out of memory error, and I'm trying to figure out how I might make it better.

My program is structured as follows:

• There is a front screen which will start an activity.
• The secondary activity is where most of the action is, and also where I crashed.
• I crash on an inflate command
• My game forces portrait mode, it was easier to make 1 layout than 2 work...
• There are a number of class variables associated with my secondary activity. I'll include the non-static ones below. I've also included some kind of a clue for those things which aren't obvious as to what they are.

What I'm wanting to know is how I can improve the memory management of my program so it won't crash. I suspect that I need to manually delete some of these variables, but I'm not sure what the right place to do so is. Thanks!

private Level_Score_bar score_bar; // Custom view
private number_viewer num_viewer; // Custom view
private number_pad num_pad;       // Custom View
private int time,score,level,num_remaining,current_var,change_loc,time_remaining;
private ArrayList<Integer> the_key;
private ImageView Number_to_select;
private Boolean update_viewer; 
Random rseed;
Vibrator bzzz;
long ctime;
private Activity self=this;

private SharedPreferences prefs;
private Editor prefs_edit;

The out of memory occurred

   setContentView(R.layout.level_layout);

This layout is rather complex, containing several image views, buttons, text views, etc.

Answer 1

So it turns out, I was right on the hairy edge of the Heap. I am using quite a few images, and it turns out that I was over the "normal" heap size. I've managed to improve this situation by shrinking some of the images, but the best solution came by changing my manifest to the following:

<application 
    android:label="@string/app_name" 
    android:icon="@drawable/logo" 
    android:screenOrientation="portrait" 
android:largeHeap="true">

The large heap will allow me to do future upgrades (Which will include level designs, etc, which would take up quite a bit of space...) All in all, it should be a pretty minimal affect.

I selected @Booger's answer as this was the piece which allowed me to do some research and figure out that my heap space just wasn't large enough, but I also included @Ramam-Mystry's piece of code.

I also used many answers from this excellent question in my quest. I started to store references instead of bitmaps, and a few other related bits. All in all, my memory consumption is down 25%, and continuing to improve.

Another tip could be to use the onLowMemory() function in Activity, trim the memory that's not needed then.

Answer 2

Try by using System.gc(); in onresume() to avoid memory leaks on using high resolution or high memory pictures in imageview.

Note: For imageviews using bitmaps, default garbage collection is not called, so the execution memory exceeds the allocated memory when images memory is higher. manual garbasge collection to be done to avoid memory leak. it is better to call in onresume();

Answer 3

It sounds like you need to check out the "Allocation Tracker" tool, which is available in the "DDMS' Perspective in eclipse.

This will show you exactly which data structures are consuming memory.