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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!news.sprintlink.net!cs.utexas.edu!geraldo.cc.utexas.edu!brazile From: brazile@math.utexas.edu (Jason Brazile) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: test&set? Semaphores? Date: 19 Oct 1995 21:48:19 GMT Organization: Department of Mathematics, University of Texas at Austin Lines: 21 Message-ID: <466h33$elf@geraldo.cc.utexas.edu> References: <460ivi$3j9@netnews.upenn.edu> NNTP-Posting-Host: max.ma.utexas.edu In article <460ivi$3j9@netnews.upenn.edu>, Darrel Herbst <dherbst@gradient.cis.upenn.edu> wrote: > What implementations are most commonly used for test&set on FreeBSD? Someone already responded on how you can get a SYSTEM V style semaphore. Using this and other SYSTEM V IPC is often overkill. As far as I know, FreeBSD is still Intel x86 only so it is OK for me to advise you to use the "xchg" instruction to write your own C-callable test_and_set() in about 6 lines of assembly. I would also advise that you look at shared memory via mmap() MAP_SHARED as opposed to SYSTEM V shared memory - if you can live with its requirement on the ancestry of your processes. Richard Steven's "Advanced Programming in the UNIX Environment" is a good book. --- Jason Brazile brazile@math.utexas.edu "People say I'm apathetic but I don't care" University of Texas