Re: [pygame] Frantic memory usage

["Brian Fisher" <brian@xxxxxxxxxxxxxxxxxxx>]

One memory-related thing I noticed right away is that each time I
start a new game, another 40MB gets allocated (so it's leaking mem).
It looks like each time you load a level you create new "collision
artifacts" managers, but the old managers get kept around. Each of
those managers finds the filmstrip it needs and splits it up into
surfaces. You don't load more than one copy of the underlying .png's
due to your cache, but each manager happily creates it's own surfaces
from the film strip (so you end up with lots of copies of the
animations). You may want to think about caching the split filmstrips,
instead of caching the .pngs, and not storing the loaded pngs at all
(what do you need them for after you've split them anyways?)

It looks like the explosion animations in particular take like 10MB a
piece...  which is no suprise at 14000x200 for the filmstrip
(14000x200x4bytes per pixel ~ 10MB)

In case you are curious, I was able to find where the 40MB for level
loading is being allocated by binary search - basically run the game a
few times, inserting a bunch of prints and time.sleep(2) calls in
order to give me a chance to look at memory usage in the task manager
after large blocks of code, before new stuff ran. It showed that the
mem was allocated in load_level_objects in game_scene.py:
		self.collisions = levels.get_collision_table()
		for o in game['collision_artifacts']:
			if o['load'] == self.level:
				manager_name = o['name']
				is_collidable = o['collidable']
				log.write_debug_msg( "Loading %s" % manager_name )
				manager_class = import_by_name( "%s.%s" % ( manager_name, manager_name ) )
				manager = manager_class()
				self.collision_artifact_managers[manager_name] = manager
				self.game_object_managers.append( manager )
				if is_collidable:
					self.collidable_collision_artifact_managers.append( manager )

what happens there, is that even though the old manager is not in the
collision_artifact_managers dict anymore, it's never removed from the
game_object_managers or collidable_collision_artifact_managers lists,
which is why they keep their memory around. (as a test, I made sure to
delete the old managers from those lists if they were already in the
dict, and then loading the level again didn't leak memory anymore)
				if (manager_name in self.collision_artifact_managers):
					old_manager = self.collision_artifact_managers[manager_name]
					self.game_object_managers.remove(old_manager)
					if is_collidable:
						self.collidable_collision_artifact_managers.remove(old_manager)
					print "skipping", manager_name


On 7/10/06, David Mikesell <dave_mikesell@xxxxxxxxxxx> wrote:
> I found some image filmstrips I was not unloading after they're cut up
> into image arrays, and it freed up a decent amount of memory, but my
> game is still a hog.  I totalled the amount of disk space for all images
> used by the starship (different weapons, explosions, thruster, etc.),
> and it's 600Kb.   However, when I comment out the line that loads the
> starship_manager, the memory usage drops by a whopping 17Mb.   It's even
> worse for the first enemy, which is loaded when the first level begins.
> 355Kb of images, but the memory usage skyrockets another 40Mb when it
> loads on the first level.
>
> I'm doing something braindead somewhere, just haven't tracked it down
> yet.   The code is spread across dozens of source files, but if anyone's
> interested it's at http://medievalelks.com/code.zip.  I honestly don't
> expect anyone to take the time to look at such a volume, but I've been
> requested several times to post it so there it is.   I didn't include
> any data files, just code.
>
> Anyway, I'm making some progress.   Oh, and I scaled down the game to
> 640x480, which also helps the performance.   Removed some
> redundant-sounding music loops, too.   Download size is now a svelte
> 13Mb :-).