This is an experimental debug tool for regrtest to try to debug http://bugs.python.org/issue30351 since faulthandler is not in the Python 2.7 stdlib (it was added to Python 3.3), and it's not that easy to install a C extension from PyPI on buildbots.

Using a thread is portable, but Python 2.7 doesn't have signal.pthread_sigmask(), so the thread may receive signals which is likely to change the behaviour of some tests relying on signals :-/

The design of this debug tool is very different from faulthandler and is likely to cause bugs when it's enabled. I'm not sure that I would like to get this change merged :-(

I wrote it to try to debug regrtest hangs on Python 2.7 on platforms without gdb with python-gdb.py plugin.

You better know what your code does. 😉

I don't think that the watchdog is reliable, it can "catch" signals (we miss signal.pthread_sigmask() on Python 2.7), and 2.7 buildbots became very stable so I don't need this tool anymore. I just abandon my PR.

I rebased my PR: 3019.

PR #3019.