Re: SIGCHLD handler in Postgres C function. - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: SIGCHLD handler in Postgres C function.
Date
Msg-id 200107302341.f6UNf6t07156@candle.pha.pa.us
Whole thread Raw
In response to Re: SIGCHLD handler in Postgres C function.  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
> Bill Studenmund <wrstuden@zembu.com> writes:
> > Looking at source on the web, I found:
> 
> > kernel/signal.c:1042
> 
> > * Note the silly behaviour of SIGCHLD: SIG_IGN means that the
> > * signal isn't actually ignored, but does automatic child
> > * reaping, while SIG_DFL is explicitly said by POSIX to force
> > * the signal to be ignored.
> 
> Hmm, interesting.  If you'll recall, the start of this thread was a
> proposal to change our backends' handling of SIGCHLD from SIG_IGN to
> SIG_DFL (and get rid of explicit tests for ECHILD).  I didn't quite see
> why changing the handler should make a difference, but above we seem to
> have the smoking gun.
> 
> Which kernel, and which version, is the above quote from?

The auto-reaping is standard SysV behavior, while BSD is really ignore. 
See the Steven's Unix Programming book for more info.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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