* Write a new test to ensure that dump_tracebacks_later() still works if
it was already called and then cancelled before
* Don't use a variable to check the status of the thread, only rely on locks
* The thread only releases cancel_event if it was able to acquire it (if
the timer was interrupted)
* The main thread always hold this lock. It is only released when
faulthandler_thread() is interrupted until this thread exits, or at Python
exit.
time.time() and/or time.sleep() are not accurate on Windows, don't test them
in test_faulthandler. Anyway, the check was written for an old implementation
of dump_tracebacks_later(), it is not more needed.
The traceback may contain "_is_owned":
Thread 0x40962b90:
File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/threading.py", line 220 in _is_owned
File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/threading.py", line 227 in wait
File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/threading.py", line 421 in wait
File "<string>", line 23 in run
File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/threading.py", line 735 in _bootstrap_inner
File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/threading.py", line 708 in _bootstrap
Current thread XXX:
File "<string>", line 10 in dump
File "<string>", line 28 in <module>
* faulthandler_user() displays the tracebacks of all threads even if it is
unable to get the state of the current thread
* test_faulthandler: only release the GIL in test_gil_released() check
* create check_signum() subfunction
