Bullet skipping enqueued tasks - found possible issue

[riccardobl]

In my code, bullet was skipping some enqueued tasks, i found out that pQueue.poll() is called twice at the beginning of this code

jmonkeyengine/jme3-bullet/src/main/java/com/jme3/bullet/PhysicsSpace.java

Lines 194 to 206 in cd1d145

	AppTask task = pQueue.poll();
	task = pQueue.poll();
	while (task != null) {
	while (task.isCancelled()) {
	task = pQueue.poll();
	}
	try {
	task.invoke();
	} catch (Exception ex) {
	logger.log(Level.SEVERE, null, ex);
	}
	task = pQueue.poll();
	}

This looks like the issue to me and without the double poll the issue is gone. I need some confirmations that i'm not breaking something i don't know.

[empirephoenix]

Yes that surely looks like a bug to me, good find, can you make a pull request for it?

[riccardobl]

Done. I've rewritten the code to make it cleaner and to prevent line 201 from logging npe if the task was cancelled and the queue over.

https://github.com/riccardobl/jmonkeyengine/blob/3e8152c3ec64eceef49b3b41dc9daf915b9f6f8d/jme3-bullet/src/main/java/com/jme3/bullet/PhysicsSpace.java#L196-L204

[stephengold]

While I agree this is a good catch, it looks to me like preTick_native() is never invoked, so rewriting it will have no effect. The same goes for PhysicsSpace.postTick_native(), addCollision_native(), needCollision_native(), addCollisionEvent_native(), and notifyCollisionGroupListeners_native().

I recommend removing all this dead code.

[stephengold]

Correction: those methods are invoked from native code, so they can't be removed.

[riccardobl]

PR has been merged, so i think it's time to close this.

[stephengold]

Thanks. I forgot to do so.