Memory test

[Luisav1]

From self code review #112.

[Luisav1]

On-hold because of CT issue #129.

[zepumph]

#129 is closed. let's do it!

[jbphet]

As part of the code review in #165 I ran a memory test. There is a screenshot of the results below. The bottom line is that there may be a slow leak, but nothing egregious, and what we do see could be explainable by pooling in Scenery.

Everything was done in a Chrome incognito window using a freshly built version of build-a-nucleus_all_phet_debug.html.

Explanation:

• Snapshot 1 - loaded, no interaction
• Snapshot 2 - after a minute of basic interaction, then a reset on both screens and a return to the home screen
• Snapshot 3 - after a reload with the fuzz parameter added and one minute of fuzzing
• Snapshots 4 thru 12 - snapshots at one minute intervals while fuzzing
• Snapshot 13 - Stopped fuzzing using phet.chipper.queryParameter.fuzz = false, reset both screens, went to the home screen

[zepumph]

When I create 10 of each nucleon and then reset, the comparison memory tool doesn't show any obvious memory leaks. Yay!

[zepumph]

We found one problem with how we were recreating a Text, PatternStringProperty, AND a DerivedProperty each time the mass number changed. Oops. Fixed here.

[zepumph]

After fuzzing for 45 minutes and capturing snapshots intermittently, I don't see problems anymore. Woo! Closing. Thanks @Luisav1 for all your help.

[zepumph]

Arg! Found another nested listener adding:

build-a-nucleus/js/common/view/NucleonNumberPanel.ts

Lines 110 to 121 in 1475ded

	nucleonCountProperty.link( () => {
	startRemovingNucleonNumberDisplay.start();
	// At the end of both animations, reset the values and opacities of oldNucleonNumberDisplay and newNucleonNumberDisplay.
	addNucleonNumberDisplay.finishEmitter.addListener( () => {
	oldNucleonNumberProperty.value = nucleonCountProperty.value;
	oldNucleonNumberDisplay.opacity = 1;
	newNucleonNumberDisplay.opacity = 0;
	} );
	} );

[zepumph]

?listenerLimit=1000 has been helpful for this nesting issue

[zepumph]

After fuzzing for a while I saw that the maxListenerCount was 783, then when I restarted the sim with ?listenerLimit=782, it failed on startup. No further work to be done here.