Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!hawk.ulowell.edu!arosen
From: arosen@hawk.ulowell.edu (MFHorn)
Newsgroups: comp.sys.sequent
Subject: Re: Semaphores
Keywords: mutex.h
Message-ID: <11964@swan.ulowell.edu>
Date: 4 Mar 89 00:20:08 GMT
References: <778@htsa.uucp>
Sender: news@swan.ulowell.edu
Reply-To: arosen@hawk.ulowell.edu
Organization: University of Lowell, CS Dept
Lines: 26

> Roaming around in the directories I've found the file
> /usr/include/sys/mutex.h .
> Some _very_ interesting routines are mentioned there. Are these routine
> for
> public use, and if so, how are they called by. 

I don't think you can call those routines from a user-level program.
I've seen most of the routines declared there in the kernel (being a
parallel architecture, you have to be very careful about resource
allocation; you're NOT the only process running).

Dynix does support user-level semaphores.  See /usr/include/sys/{sem,ipc}.h
and the man pages for semop, semget and semctl.

I also have a program written by Jim Pickering that was posted some time
ago which graphically (curses) illustrates the dining philosophers problem
using semaphores.

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Andy Rosen           | arosen@hawk.ulowell.edu | "I got this guitar and I
ULowell, Box #3031   | ulowell!arosen          |  learned how to make it
Lowell, Ma 01854     |                         |  talk" -Thunder Road
		RD in '88 - The way it should've been