Re: pgsql: Don't send protocol messages to a shm_mq that no longer exists.

On Fri, Oct 16, 2015 at 9:50 AM, Robert Haas <rhaas@postgresql.org> wrote:
> Don't send protocol messages to a shm_mq that no longer exists.
>
> Commit 2bd9e412f92bc6a68f3e8bcb18e04955cc35001d introduced a mechanism
> for relaying protocol messages from a background worker to another
> backend via a shm_mq.  However, there was no provision for shutting
> down the communication channel.  Therefore, a protocol message sent
> late in the shutdown sequence, such as a DEBUG message resulting from
> cranking up log_min_messages, could crash the server.  To fix, install
> an on_dsm_detach callback that disables sending messages to the shm_mq
> when the associated DSM is detached.

And of course that should have set client_min_messages.  Sigh.

--
Robert Haas
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