Horton

Re: Windows buildfarm members vs. new async-notify isolation test

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Mark Dilger <hornschnorter@gmail.com>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-12-04T05:12:27Z
Lists: pgsql-hackers 
Amit Kapila <amit.kapila16@gmail.com> writes:
> On Tue, Dec 3, 2019 at 10:10 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Hmm ... just looking at the code again, could it be that there's
>> no well-placed CHECK_FOR_INTERRUPTS?  Andrew, could you see if
>> injecting one in what 790026972 added to postgres.c helps?

> I also tried to analyze this failure and it seems this is a good bet,
> but I am also wondering why we have never seen such a timing issue in
> other somewhat similar tests.  For ex.,  one with comment (#
> Cross-backend notification delivery.).  Do they have a better way of
> ensuring that the notification will be received or is it purely
> coincidental that they haven't seen such a symptom?

TBH, my bet is that this *won't* fix it, but it seemed like an easy
thing to test.  For this to fix it, you'd have to suppose that we
never do a CHECK_FOR_INTERRUPTS during a COMMIT command, which is
improbable at best.

			regards, tom lane

Commits

  1. Use only one thread to handle incoming signals on Windows.

  2. Fix race condition in our Windows signal emulation.