Horton

Re: [sqlsmith] stuck spinlock in pg_stat_get_wal_receiver after OOM

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Andreas Seltenreich <seltenreich@gmx.de>, pgsql-hackers@postgresql.org, Alvaro Herrera <alvherre@2ndquadrant.com>, Michael Paquier <michael.paquier@gmail.com>
Date: 2017-10-02T21:34:42Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> On 2017-10-02 17:30:25 -0400, Tom Lane wrote:
>> Or replace the spinlock with an LWLock?

> That'd probably be a good idea, but I'm loathe to do so in the back
> branches. Not at this callsite, but some others, there's some potential
> for contention.

If this is the only problem then I'd agree we should stick to a spinlock
(I assume the strings in question can't be very long).  I was thinking
more about what to do if we find other violations that are harder to fix.

			regards, tom lane

Commits

  1. Fix race condition with unprotected use of a latch pointer variable.

  2. Fix coding rules violations in walreceiver.c

  3. Use latch instead of select() in walreceiver