New submission from STINNER Victor <vstin...@python.org>:
At fork, Python calls PyOS_AfterFork_Child() in the child process which indirectly calls _PyThreadState_DeleteExcept() whichs calls release_sentinel() of the thread which releases the thread state lock (threading.Thread._tstate_lock). Problem: using a lock after fork is unsafe and can crash. That's exactly what happens randomly on AIX when stressing ThreadJoinOnShutdown.test_reinit_tls_after_fork() of test_threading: https://bugs.python.org/issue40068#msg365031 There are different options to solve this issue: * Reset _tstate_lock before using it... not sure that it's worth it, since we are going to delete the threading.Thread object with its _tstate_lock object anymore. After calling fork, the child process has exactly 1 thread: all other threads have been removed. * Modify release_sentinel() to not use the lock: avoid PyThread_release_lock() call. ---------- components: Interpreter Core messages: 365173 nosy: vstinner priority: normal severity: normal status: open title: Crash in _PyThreadState_DeleteExcept() at fork in the process child versions: Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue40092> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
