Re: Review: Extra Daemons / bgworker

Andres Freund <andres@2ndquadrant.com>

From: Andres Freund <andres@2ndquadrant.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Markus Wanner <markus@bluegap.ch>, kaigai@kaigai.gr.jp, PostgreSQL-development Hackers <pgsql-hackers@postgresql.org>
Date: 2012-12-05T22:25:02Z
Lists: pgsql-hackers
On 2012-12-05 18:42:42 -0300, Alvaro Herrera wrote:
> >    <para>
> >     <structfield>bgw_sighup</structfield> and <structfield>bgw_sigterm</> are
> >     pointers to functions that will be installed as signal handlers for the new
> > -   process.
> > +   process. XXX: Can they be NULL?
> >    </para>
>
> Hm.  The code doesn't check, so what happens is probably a bug anyhow.
> I don't know whether sigaction crashes in this case; its manpage doesn't
> say.  I guess the right thing to do is have RegisterBackgroundWorker
> check for a NULL sighandler, and set it to something standard if so (say
> SIG_IGN for SIGHUP and maybe quickdie() or similar for SIGTERM).

Afair a NULL sigaction is used to query the current handler. Which
indirectly might lead to problems due to the wrong handler being called.

Setting up SIG_IGN and quickdie in that case seems to be sensible.

Greetings,

Andres Freund

--
 Andres Freund	                   http://www.2ndQuadrant.com/
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