WebGLProgram leaking (instances increasing) about three.js HOT 5 CLOSED

I have debugged the example and it seems the internal program cache does not retain outdated program references. When you call material.dispose(), the renderer checks if an instance of WebGLProgram is still required and if not, releases it and removes internal references. The code that triggers these operations is:

When a program is removed, keep in mind that it is not immediately removed from memory. That happens when the GC runs and we can't influence when the JS environment decides to run it.

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Hello @Mugen87, thank you for looking into this issue. I forced garbage collection (in memory profile tab its 5th icon, first is to take heap memory snapshot), but unfortunatelly it didnt garbage collectied it in next snapshot.

What seems to be leaking is WebGLProgram from webgl context, a gpu resource, not the class wrapper which is called WebGLProgram too. To confirm this I renamed wrapper class to be sure.

It looks like this WebGLProgram program instance reference is still somewhere and it is preventing garbage collection. I already spend few hours on this and I am more familiar with the issue, but I am not able to figure out this out yet.

I also found some "similar" issue from that past. I am not sure if its related or not yet.
#19645

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I also found some "similar" issue from that past. I am not sure if its related or not yet.
#19645

It is not related, imo. Render states have no references to programs.

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I've checked the relevant code base again I don't think the root cause is on our side. Especially the behavior you have described here makes me think this is a browser related issue:

Number of instances seems to be capped at ~131 for my computer which is very strange.
Also then it seems like all above 131 will get deleted correctly which is even more weird.

To me, this does not look like a memory leak. I suspect what we see is some sort of cashing mechanism of the browser to retain programs for a potential later use. Even if an app does not use a program for rendering anymore, it might be use it at a later point. Next to optimizations on engine levels, WebGL implementations apply optimizations as well to avoid unnecessary overhead. If the browser caching is implemented correctly, is a different question.

But to be honest, if there is no ongoing growing memory allocation that eventually slows down the app or crashes the tab, I would not worry about 131 instances of WebGLProgram retained somewhere in memory. If you insist to report it, do it here: https://issues.chromium.org/issues.

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I kind of agree with your conclusion. If I find some other reason or evidence I will report it.
I tried several code changes to get rid of those WebGLPrograms but I was unable to achieve it.

Also thanks for the link to chromium I will try to ask for advice / confirmation there.

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