On 2016-10-14 13:50:35 -0400, Tom Lane wrote: > Heikki Linnakangas <hlinn...@iki.fi> writes: > > On 14 October 2016 16:22:12 EEST, Tom Lane <t...@sss.pgh.pa.us> wrote: > >> I don't know whether to laugh or cry, but that code is a joke. Just > >> silently fail if you can't get the lock? > > > Heh, ok, let me rephrase: I believe it's *intended* to be callable from a > > signal handler :). Whether it actually works is another question. Perhaps > > there's some mitigating conditions there, I don't know. > > > For our use case, it's actually not too bad if Py_AddPendingCall gives up > > and does nothing. Then the python function will simply not be interrupted > > until next SPI call, which is the current situation anyway. > > I dunno. If the failure were very low-probability, you could maybe live > with that behavior, but I'm not sure it is. Presumably the Python > interpreter loop is taking that lock once per statement (at least), so > that it can tell if there's something to do. That'd suggest that the > fraction of time in which the lock is held is not negligible.
Since that's how python's signal handling works, I'm not sure that's really our problem. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
