From owner-freebsd-hackers  Fri Aug 25 11:28:59 2000
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Date: Fri, 25 Aug 2000 11:28:47 -0700
From: "'Alfred Perlstein'" <bright@wintelcom.net>
To: Ben Smithurst <ben@FreeBSD.org>
Cc: "Yevmenkin, Maksim N, CSCIO" <myevmenkin@att.com>,
	core-ix@hushmail.com, freebsd-hackers@FreeBSD.org
Subject: Re: Preventing zombies to occure
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References: <E598F159668DD311B9C700902799EAF44734E5@njb140po01.ems.att.com> <20000825062409.O1209@fw.wintelcom.net> <20000825175439.C30144@strontium.scientia.demon.co.uk>
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* Ben Smithurst <ben@FreeBSD.org> [000825 10:15] wrote:
> 'Alfred Perlstein' wrote:
> 
> > int
> > sigchld_handler(int) 
> > {
> > 
> > 	while (waitpid(-1, NULL, 0) || errno == EINTR)
> > 		;
> > }
> 
> Even more paranoid would be
> 
> int
> sigchld_handler(int)
> {
> 	int e = errno;
> 
> 	while (waitpid(-1, NULL, 0) || errno == EINTR)
> 		;
> 
> 	errno = e;
> }
> 
> otherwise you could get bogus errors reported, I think.
> 
> 	if ((fp = fopen(foo, "r")) == NULL)
> 		/* SIGCHLD arrives here */
> 		warn("can't open foo");

The code I presented is flawed as a result of an allnighter dealing
with postresql.  I'll enjoy thinking about this over the weekend. :)

-Alfred


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