Gregory P. Smith added the comment: This report is based on manual code inspection in CPython head after we encountered a deadlock using pytracemalloc on Python 2.7.12 where it _appeared_ to be the scenario I've described.
I see now that I missed noticing the "#ifndef Py_HAVE_NATIVE_TLS" within thread.c which should imply a different PyThread_get_key_value() implementation that likely does not use our lock acquiring fallback find_key(). So my code analysis may not make sense... To give a taste of the large process setup we saw it in: * A CPython process that has extension modules which create their own threads as well as potentially Python having created its own threads. * We've called faulthandler.enable() *and* faulthandler.register(SIGTERM). * We send a SIGTERM to processes in this environment which are taking too long to complete; the goal was to get a stack trace of what the process was potentially stuck doing when our external timeout monitoring mechanism kicked in. our stuck process had received the SIGTERM and analyzing it revealed a deadlock between two threads which appeared to involve this faulthandler path. let me gather more info into one place. from there i should be able to come up with a way to reproduce it (or even better, not) ---------- assignee: haypo -> gregory.p.smith _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue30165> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
