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Date:      Wed, 4 Feb 1998 10:54:32 +0200 (SAT)
From:      Graham Wheeler <gram@cdsec.com>
To:        Michael.Schuster@utimaco.co.at (Michael Schuster)
Cc:        hackers@FreeBSD.ORG
Subject:   Re: Shared memory and signals
Message-ID:  <199802040854.KAA11487@cdsec.com>
In-Reply-To: <34D8136F.CF845A68@utimaco.co.at> from "Michael Schuster" at Feb 4, 98 08:06:23 am

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> 
> Graham Wheeler <gram@cdsec.com> wrote:
> 
> >I notice from looking at the kernel source
> >that it appears as if an exit() effectively does a shmdt for each shared
> >memory segment, but not a shmctl(IPC_RMID,..).

> You probably wouldn't want to do that, since shmctl(IPC_RMID,..) really
> removes the shm segment, and other processes trying to use it wouldn't
> be very happy about that ...

If the shmctl is done from the SIGCHLD handler, I know that there are
no other processes still using the segment (as the only other process 
using the segment was the one that terminated and caused the SIGCHLD signal...)

-- 
Dr Graham Wheeler                          E-mail: gram@cdsec.com
Citadel Data Security                      Phone:  +27(21)23-6065/6/7
Internet/Intranet Network Specialists      Mobile: +27(83)-253-9864
Firewalls/Virtual Private Networks         Fax:    +27(21)24-3656
Data Security Products                     WWW:    http://www.cdsec.com/






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