On Sat, Mar 25, 2017 at 5:26 PM, Kuntal Ghosh <kuntalghosh.2...@gmail.com> wrote: > On Fri, Mar 24, 2017 at 9:23 PM, Robert Haas <robertmh...@gmail.com> wrote: >> I think this is still not good. The places where pgstat_bestart() has >> been added are not even correct. For example, the call added to >> BackgroundWriterMain() occurs after the section that does >> error-recovery, so it would get repeated every time the background >> writer recovers from an error. There are similar problems elsewhere. >> Furthermore, although in theory there's an idea here that we're making >> it no longer the responsibility of InitPostgres() to call >> pgstat_bestart(), the patch as proposed only removes one of the two >> calls, so we really don't even have a consistent practice. I think >> it's better to go with the idea of having InitPostgres() be >> responsible for calling this for regular backends, and >> AuxiliaryProcessMain() for auxiliary backends. That involves >> substantially fewer calls to pgstat_bestart() and they are spread >> across only two functions, which IMHO makes fewer bugs of omission a >> lot less likely. > > Agreed. Calling it from InitPostgres() and AuxiliaryProcessMain() > seems correct because of the following two reasons as you've mentioned > up in the thread: > 1. security-filtering should be left to some higher-level facility > that can make policy decisions rather than being hard-coded in the > individual modules. > 2. makes fewer bugs of omission a lot less likely.
Okay, fine for me. >> - I modified the code to tolerate a NULL return from >> AuxiliaryPidGetProc(). I am pretty sure that without that there's a >> race condition that could lead to a crash if somebody tried to call >> this function just as an auxiliary process was terminating. > > Wow. Haven't thought of that. If it's called after > AuxiliaryProcKill(), a crash is evident. This one is a good catch. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
