Date: Thu, 13 Jun 1996 00:57:46 GMT From: James Raynard <fqueries@jraynard.demon.co.uk> To: eeg@telecom.at Cc: FreeBSD-questions@freebsd.org Message-ID: <199606130057.AAA15921@jraynard.demon.co.uk> In-Reply-To: <199606122142.VAA02488@fh> (message from Franz Hollerer on Wed, 12 Jun 1996 21:42:14 GMT)
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> I use semaphore to control read and write access to a
> shared memory.
> For the different semop() I set the SEM_UNDO flag.
> So the kernel should undo the semaphore operations if the
> process exits or is killed.
> With Linux and SCO this works. But under FreeBSD 2.1
> all other processes (which wait for the semaphore) hang.
>
> *) Please, can someone tell me, if this is a bug in
> my program or a bug in the FreeBSD kernel?
Yep, this is a bug in -release which has since been fixed. Apply the
following patch in /usr/src/sys/kern/kern_exit.c:-
*** kern_exit.c Tue May 30 17:05:25 1995
--- kern_exit.c.new Wed Dec 6 15:12:28 1995
***************
*** 130,135 ****
--- 130,139 ----
*/
fdfree(p);
+ #ifdef SYSVSEM
+ semexit(p);
+ #endif
+
/* The next two chunks should probably be moved to vmspace_exit. */
vm = p->p_vmspace;
#ifdef SYSVSHM
(and also add #include <sys/sem.h> at the top of the file).
--
James Raynard, Edinburgh, Scotland
james@jraynard.demon.co.uk
jraynard@FreeBSD.ORG
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