Question

I’m having some trouble with memory management in a flash app. Memory usage grows quite a bit, and I’ve tracked it down to the way I load assets.

I embed several raster images in a class Embedded, like this

[Embed(source="/home/gabriel/text_hard.jpg")]
public static var ASSET_text_hard_DOT_jpg : Class;

I then instance the assets this way

var pClass : Class = Embedded[sResource] as Class;
return new pClass() as Bitmap;

At this point, memory usage goes up, which is perfectly normal. However, nulling all the references to the object doesn’t free the memory.

Based on this behavior, looks like the flash player is creating an instance of the class the first time I request it, but never ever releases it – not without references, calling System.gc(), doing the double LocalConnection trick, or calling dispose() on the BitmapData objects.

Of course, this is very undesirable – memory usage would grow until everything in the SWFs is instanced, regardless of whether I stopped using some asset long ago.

Is my analysis correct? Can anything be done to fix this?

Answer 1

It turns out I was keeping references to the objects that didn’t unload. Very tricky ones. The GC does work correctly in all the cases I described, which I suspected may have been different.

More precisely, loading a SWF, instancing lots of classes defined in it, adding them to the display list, manipulating them, and then removing all references and unloading the SWF leaves me with almost exactly the same memory I started with.