Re: Review: Extra Daemons / bgworker

Andres Freund wrote:
> On 2012-12-05 12:09:58 -0300, Alvaro Herrera wrote:
> > Here's a first attempt at a new documentation chapter. This goes in
> > part "Server Programming", just after the SPI chapter.
> >
> > I just noticed that worker_spi could use some more sample code, for
> > example auth_counter was getting its own LWLock and also its own shmem
> > area, which would be helpful to demonstrate I think.
>
> I am not exactly renowned for my english skills, but I have made a pass
> over the file made some slight changes and extended it in two places.

Thanks, I have applied it.

> I've also added a comment with a question that came to my mind when
> reading the docs...

> <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).

--
Álvaro Herrera http://www.2ndQuadrant.com/
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