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From: fkittred@bbn.com (Fletcher Kittredge)
Newsgroups: comp.unix.ultrix
Subject: Re: CMA threads usage?
Message-ID: <61984@bbn.BBN.COM>
Date: 10 Jan 91 01:09:15 GMT
References: <331@oiscola.Columbia.NCR.COM>
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Reply-To: fkittred@spca.bbn.com (Fletcher Kittredge)
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Organization: Bolt Beranek and Newman Inc., Cambridge MA
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In article <331@oiscola.Columbia.NCR.COM> kornegay@oiscola.UUCP (Michael L. Kornegay) writes:
>I have looked at the CMA threads package as a potential means to 
>execute multi-threaded software under Unix.  I need threads to have
>the following semantics:  a thread executing a blocking system call
>(eg: read(...)) should only block itself and allow other threads to
>continue to execute, and preemptive scheduling of threads allowing
>the currently executing thread to be preempted if a higher priority
>thread becomes ready.  CMA threads do not have this functionality.
>

How soon do you need this functionality and how good are your connections?

OSF/1 has this functionality in the form of a POSIX 1003.4a Draft 4 threads
package and  (I think) the Mach C-threads package.  OSF/1 is currently
available from OSF for the DECStation.  DEC is selling developer's versions
of OSF/1 this quarter, and the Ultrix/OSF merge is due out this year.
If you know the right people in DEC or the OSF, then you should be able
to get OSF/1 pretty quickly.

My understanding is that CMA is going to be replaced by Pthreads.  We are
aiming our (extensive) threads development at that enviroment.

You could also get the Mach 3.0 micro-kernel free from CMU, but you need full
Unix source licenses to do anything useful with it.

regards,
fletcher
Fletcher Kittredge
Platforms and Tools Group, BBN Software Products
10 Fawcett Street,  Cambridge, MA. 02138
617-873-3465  /  fkittred@bbn.com  /  fkittred@das.harvard.edu