From: Anthony Martin <ality@pbrane.org>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] Different results for the same rc script when using listen1
Date: Sun, 24 Apr 2011 19:00:29 -0700 [thread overview]
Message-ID: <20110425020029.GA29551@dinah> (raw)
In-Reply-To: <ip2egi$83e$1@dough.gmane.org>
> This is really weird. I don't even know what could I check. 'listen1'
> source code is pretty clean, and it calls command and args with a simple
> 'exec' call. The only thing that was also unusual is that the 'net'
> variable, which is supposed to be set to a directory, is always blank,
> but the line with 'putenv' and 'net' in 'listen1.c' is commented out,
> so this is to be expected.
It fails on my Linux machine also. It's because an rfork with
RFNOWAIT sets up a child proc that will ignore SIGCHLD. If the
program that is executed (in this case rc) calls fork or exec
all SIGCHLD signals will be ignored, see signal(7).
Ultimately, this causes rc to set status='' for every process
it forks. That's why all those tests are returning true.
The solution is probably just reenabling the SIGCHLD handler
at /usr/local/plan9/src/lib9/rfork.c:96 after the second fork.
Anthony
next prev parent reply other threads:[~2011-04-25 2:00 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-24 5:09 Maurício CA
2011-04-24 5:22 ` andrey mirtchovski
2011-04-24 7:30 ` Maurício CA
2011-04-24 14:20 ` smiley
2011-04-24 17:05 ` Maurício CA
2011-04-24 17:17 ` Bakul Shah
2011-04-25 0:16 ` Maurício CA
2011-04-25 2:00 ` Anthony Martin [this message]
2011-04-25 3:14 ` Maurício CA
2011-04-25 3:17 ` erik quanstrom
2011-04-25 3:36 ` erik quanstrom
2011-04-25 3:58 ` Bakul Shah
2011-04-25 4:39 ` erik quanstrom
2011-04-25 5:27 ` Lyndon Nerenberg
2011-04-25 5:53 ` Bakul Shah
2011-04-25 6:59 ` Robert Ransom
2011-04-25 14:56 ` Bakul Shah
2011-04-25 15:00 ` erik quanstrom
2011-04-25 16:17 ` Skip Tavakkolian
2011-04-25 16:27 ` Joseph Stewart
2011-04-25 20:13 ` smiley
2011-04-25 20:16 ` Lyndon Nerenberg
2011-04-25 20:18 ` erik quanstrom
2011-04-25 14:44 ` erik quanstrom
2011-04-25 13:53 ` Maurício CA
2011-04-25 14:42 ` erik quanstrom
2011-04-27 21:57 ` Maurício CA
2011-04-26 9:02 ` dexen deVries
2011-04-26 12:57 ` erik quanstrom
2011-04-25 2:03 ` andrey mirtchovski
2011-04-25 2:14 ` Iruatã Souza
2011-04-25 2:20 ` andrey mirtchovski
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