Xref: utzoo comp.os.misc:1420 rec.ham-radio:28891 Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!news.cs.indiana.edu!msi.umn.edu!cs.umn.edu!quest!ssb From: ssb@quest.UUCP (Scott Sheldon Bertilson) Newsgroups: comp.os.misc,rec.ham-radio Subject: Re: What should a scheduler do? Message-ID: <1990Dec28.021435.11795@quest.UUCP> Date: 28 Dec 90 02:14:35 GMT References: <1990Dec06.212613.25912@ism.isc.com> <1990Dec17.214336.8190@ni.umd.edu> Organization: Quest Research, Inc. Lines: 17 I've hacked a little on a version of NOS that Anders Klemets ported to System V UNIX. It uses shared memory and semaphores. Each application runs in a separate process and uses a simulated socket library to communicate with the server process. I don't think Anders sees it as anything more than an experiment because the overhead of synchronization using semaphores does a good job of gobbling up substantially more than a 10 MHz 68010 (my AT&T 3B1). I made a change to interlock using a test-and-set instruction on some shared memory before trying to get a major semaphore..it increased the efficiency of the package enough so that it is reasonably snappy, but I've had problems with synchronization not working properly, so I can't call it a success. -- Scott S. Bertilson ...ssb@quest.UUCP scott@poincare.geom.umn.edu