AS3 Memory Conservation (Loaders/BitmapDatas/Bitmaps/Sprites)

Question

I'm working on reducing the memory requirements of my AS3 app. I understand that once there are no remaining references to an object, it is flagged as being a candidate for garbage collection.

Is it even worth it to try to remove references to Loaders that are no longer actively in use? My first thought is that it is not worth it.

Here's why: My Sprites need perpetual references to the Bitmaps they display (since the Sprites are always visible in my app). So, the Bitmaps cannot be garbage collected. The Bitmaps rely upon BitmapData objects for their data, so we can't get rid of them. (Up until this point it's all pretty straightforward).

Here's where I'm unsure of what's going on: Does a BitmapData have a reference to the data loaded by the Loader? In other words, is BitmapData essentially just a wrapper that has a reference to loader.content, or is the data copied from loader.content to BitmapData?

If a reference is maintained, then I don't get anything by garbage collecting my loaders...

Thoughts?

Answer 1

Using AMF a bit with third party products has lead me to believe the Loader class attempts to instantiate a new class of the given content type (in this case it would be a Bitmap class instance). You are probably constructing a new BitmapData object from your Bitmap instance. From that I would assume that the Loader instance references the Bitmap instance, and in your case your code also references the Bitmap instance. Unless at some point you are calling BitmapData.clone().

There are also a couple of ways to force GC. Force Garbage Collection in AS3?

You may find it useful to attach some arbitrarily large object to something, then force the GC to see if that thing is getting cleaned up or floating around. If you are using Windows something like procmon (http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx) is more helpful than task manager for doing this kind of external inspection.

This of course is a bit trial and error but for lack of something like Visual VM (https://visualvm.dev.java.net/) we are kind of screwed in the Flash world.