WebXRManager session events listeners never released

[WORMSS]

Description

I am going to prefix this with a "I may be wasting your time".
I don't have a direct way to observe if this is a memory leak or not as my Meta Quest browser doesn't have debugging.

But in WebXRManager setSession the internal session is overwritten and the new one has all the events added to it.

But, if you were to call setSession again before endSession event triggers, either with a new session or a null, it becomes impossible to remove the event listeners.

I can understand this is by far not a priority, and any booboos this causes is all at the fault of the developer calling setSession twice..

I just happened to spot it as a potential problem and wanted to highlight it.

If it's deemed as not a problem then I will know not to highlight any other similar issues I may spot in the future when looking through the code.

Reproduction steps

const session = await navigator.xr?.offerSession('immersive-ar', {
  requiredFeatures: ['local'],
});
renderer.xr.setReferenceSpaceType('local');
await renderer.xr.setSession(session);
await renderer.xr.setSession(null);

Code

const session = await navigator.xr?.offerSession('immersive-ar', {
  requiredFeatures: ['local'],
});
renderer.xr.setReferenceSpaceType('local');
await renderer.xr.setSession(session);
await renderer.xr.setSession(null);

Live example

• jsfiddle-latest-release WebGLRenderer
• jsfiddle-dev WebGLRenderer
• jsfiddle-latest-release WebGPURenderer
• jsfiddle-dev WebGPURenderer

Screenshots

No response

Version

176

Device

Headset

Browser

Quest Browser

OS

Linux

[Mugen87]

But, if you were to call setSession again before endSession event triggers, either with a new session or a null, it becomes impossible to remove the event listeners.

Does this actually matter? If the session is overwritten with a new session or null, it should be GC collected. Besides, the event listener functions onSessionEvent(), onSessionEnd() and onInputSourcesChange() are only defined once and reused. So I doubt there are any side effects.

as my Meta Quest browser doesn't have debugging.

If you connect the Quest with USB to a computer, you can debug your WebXR application with Chrome and chrome://inspect/#devices. You must enable USB debugging on your Quest though which requires enabling development mode first.