On Wed, Feb 07, 2024 at 10:40:50AM -0800, Andres Freund wrote: > On 2024-02-07 11:15:54 -0600, Nathan Bossart wrote: >> Perhaps we should add a file global bool that is only set during >> wrapper_handler(). Then we could Assert() or elog(ERROR, ...) if >> pqsignal() is called with it set. > > In older branches that might have been harder (due to forking from a signal > handler and non-fatal errors thrown from signal handlers), but these days I > think that should work. > > FWIW, I don't think elog(ERROR) would be appropriate, that'd be jumping out of > a signal handler :)
*facepalm* Yes. > If it were just for the purpose of avoiding the issue you brought up it might > not quite be worth it - but there are a lot of things we want to forbid in a > signal handler. Memory allocations, acquiring locks, throwing non-panic > errors, etc. That's one of the main reasons I like a common wrapper signal > handler. > > Which reminded me of https://postgr.es/m/87msstvper.fsf%40163.com - the set of > things we want to forbid are similar. I'm not sure there's really room to > harmonize things, but I thought I'd raise it. > > Perhaps we should make the state a bitmap and have a single > AssertNotInState(HOLDING_SPINLOCK | IN_SIGNALHANDLER) Seems worth a try. I'll go ahead and proceed with these patches and leave this improvement for another thread. -- Nathan Bossart Amazon Web Services: https://aws.amazon.com
