1230336 - Hang trying to quit and open a new browser window at the same time

Status: RESOLVED WORKSFORME

(Core :: XPCOM, defect)

Description

[Jesse Ruderman]

Attachment: testcase

1. Set up a new profile with:
  A. https://github.com/MozillaSecurity/funfuzz/blob/master/dom/automation/constant-prefs.js as prefs.js
  B. Add:
       user_pref("nglayout.debug.disable_xul_cache", true);
  C. https://github.com/MozillaSecurity/funfuzz/tree/master/dom/extension/ installed in the profile
       (either wget + drag https://www.squarefree.com/extensions/domFuzzLite3.xpi, or do the text file thing)

2. Save a local copy of the testcase

3. firefox h.html

Result: Firefox hangs (beachballing but not hogging CPU) about 50% of the time.

Comment 1

[Jesse Ruderman]

Attachment: hang sample

nsEventQueue.cpp  @ nsEventQueue::GetEvent

55    mEventsAvailable.Wait();

Comment 2

[Jesse Ruderman]

This will prevent me from finding some other hang bugs.

Comment 3

[Andrei Purice]

Following the reporter's steps I am able to confirm that the issues doesn't happen anymore on MacOs 10.15 on any of the current versions of Firefox Nightly 87.0a1 (2021-02-15), beta 86.0 and release 85.0.2. The example test case doesn't hang Firefox anymore.

Closing this issue as Resolved > Worksforme.
Feel free to re-open or file a new bug if this issue reoccurs again.