Re: SIGQUIT handling, redux

I wrote:
> Stephen Frost <sfrost(at)snowman(dot)net> writes:
>> As I mentioned over there, I agree that we should do this and we should
>> further have the statistics collector also do so, which currently sets
>> up SIGQUIT with ShutdownRequestPending() and in its loop decides it's
>> fine to write out the stats file (which we're going to remove during
>> recovery anyway...) and then call exit(0).

> I noticed that that was different from everything else, but it's not
> actually signal-unsafe, so it seems like a different topic from what
> I'm on about at the moment. I don't mind if you or somebody else
> wants to change it, but I don't see it as a back-patchable bug fix.

Note also that the postmaster actually uses SIGQUIT to command normal
shutdown of the stats collector (cf reaper(), around line 3125 in HEAD).
So this needs a change in signaling conventions, not just internal
tweaks in the collector. Not a big deal, but it reinforces my feeling
that it should be a HEAD-only change.

regards, tom lane