Fix l0 teardown and sycl windows teardown

[nrspruit]

No description provided.

[kbenzie]

The additional documentation on shutdown behavior topic is very useful.

[cperkinsintel]

We are seeing this unrelated Jenkins/Precommit failure in other PR. (e.g. #18014 ) .

[steffenlarsen]

Mostly small comments, but overall I think it looks good. Sorry for the delay!

[steffenlarsen]

Nit;

Suggested change

	if (!Lock.owns_lock()) {
	if (allowWait)
	return false; // Record was not removed, the caller may try again.
	else
	return true; // skip.
	}
	// If we fail to acquire the lock, return false if the record is still there
	// and the caller can try again. Return true if the record is gone and
	// the caller should skip.
	if (!Lock.owns_lock())
	return !allowWait;

[cperkinsintel]

Since you have said this is only a "nit" I'd like to keep it as is, as I think it is easier to read and see the logic as it's written now. Returning !allowWait is definitely an abbreviation, but it doesn't tie into the comment.

[steffenlarsen]

Personally, I don't think allowWait has any clear ties either way. In general, if (X) return false else return true is a bit of a logics anti-pattern. You can leave it, but as an outside reader, I think they convey the information equally well. You can also reword the comment if you can think of a better way of explaining it.