Re: EINTR in ftruncate()

On Thu, Jul 7, 2022 at 9:03 AM Andres Freund <andres@anarazel.de> wrote:
> On 2022-07-07 08:56:33 +1200, Thomas Munro wrote:
> > On Thu, Jul 7, 2022 at 8:39 AM Andres Freund <andres@anarazel.de> wrote:
> > > So I think we need: 1) block most signals, 2) a retry loop *without*
> > > interrupt checks.
> >
> > Yeah.  I was also wondering about wrapping the whole function in
> > PG_SETMASK(&BlockSig), PG_SETMASK(&UnBlockSig), but also leaving the
> > while (rc == EINTR) loop there (without the check for *Pending
> > variables), only because otherwise when you attach a debugger and
> > continue you'll get a spurious EINTR and it'll interfere with program
> > execution.  All blockable signals would be blocked *except* SIGQUIT,
> > which means that fast shutdown/crash will still work.  It seems nice
> > to leave that way to interrupt it without resorting to SIGKILL.
>
> Fast shutdown shouldn't use SIGQUIT - did you mean immediate? I think
> it's fine to allow immediate shutdowns, but I don't think we should
> allow fast shutdowns to interrupt it.

Err, yeah, that one.