Path: utzoo!utgpu!cunews2!bnrgate!brchh104!brchs1!bnr.ca!rice.edu!sun-spots-request
From: metcalf@masala.lcs.mit.edu (Chris Metcalf)
Newsgroups: comp.sys.sun
Subject: IPC semaphores:  anyone used them?
Keywords: SunOS
Message-ID: <2903@brchh104.bnr.ca>
Date: 23 May 91 18:47:00 GMT
Sender: news@brchh104.bnr.ca
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Original-Date: Fri, 3 May 91 14:55:49 EDT
X-Sun-Spots-Digest: Volume 10, Issue 94, message 8
X-Note: Submissions: sun-spots@rice.edu, Admin: sun-spots-request@rice.edu

I'm trying to use the SysV semaphore stuff (semget, semctl, semop) on a
variety of Sun 4s running SunOS 4.1.  Certain calls to semop() pretty
nearly crash the machine (in particular, a call with two sembufs with a
positive and a negative sem_op will do this).  The result is that the
window system freezes and no new processes are forked:  a remote xload
will keep going, and inetd will hand out sockets, but you can't do
anything more without a reboot.

Has anyone used the semaphore stuff, and (possibly) seen this?  Is it a
bug in 4.1?

Thanks very much!

Chris Metcalf, MIT Laboratory for Computer Science
metcalf@masala.lcs.mit.edu // (617) 253-7766