Memory leak

[jessegreenberg]

From #398. I noticed the following profile after recording heap size every 30 seconds or so, 98.6MB is larger than I usually see so I am wondering if this sim has a memory leak.

[jessegreenberg]

I am not too familiar with chrome memory tools, but I think this comparison view indicates a leak of many Vector2s and Bounds2s? And maybe other things too.

[jessegreenberg]

Using studio to visualize instances, I see this count at the top:
On load:

After dragging 3 track segments into the play area:

After pressing Reset All:

Reset All increasing instance count is the strangest.

[jessegreenberg]

Every time I press ResetAllButton, instance count increases by ~115.

[jessegreenberg]

When I press ResetAllButton, I see new instances of Tracks and ControlPoints in studio. Reset All eventually calls clearTracks, calling addDraggableTracks, creating new tracks for the toolbox. Ill probably start there.

[jessegreenberg]

To find the leak in reset, I hacked EnergySkateParkBasicsModel.manualStep to call EnergySkateParkBasicsModel.reset. Pressing and holding the step button for 10 seconds with this causes the sim to grow to 200 MB.

[jessegreenberg]

Lots of Objects like this in the chrome memory comparison indicate that detachableProperty is not being disposed.

[jessegreenberg]

Other than a RadioButtonGroup, it looks like TrackNode is the only place that adds listeners to detachableProperty, TrackNodes are never disposed.

[jessegreenberg]

Removing the listener in TrackNode really helps, holding the step button (that is hacked to call reset) for 20 seconds, and the heap only grows a couple of MB.

[jessegreenberg]

New memory profile fuzzing screen 3, snapshot taken every 30 seconds:

[jessegreenberg]

Fuzzing all screens for 30 seconds:

[jessegreenberg]

Memory profile over 10 seconds of fuzzing:

I think we are there!