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From: rml@bighornuswest.com (Robert Lund)
Newsgroups: comp.lang.c++
Subject: Re: AT&T C++ 2.1 Task Library
Message-ID: <1991Jun4.143542.16431@cherokee.uswest.com>
Date: 4 Jun 91 14:35:42 GMT
References: <1991Jun04.082950.1918@lut.ac.uk>
Sender: rml@bighorn (Robert Lund)
Organization: U S WEST Advanced Technologies
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In article <1991Jun04.082950.1918@lut.ac.uk>, cojrp@lut.ac.uk (JR Pitchers) writes:
> We have purchased AT&T C++ for our HP 840 system. We have ported all but the
> Task Library. According to the documentation, AT&T have ported it to various
> targets, eg: AT&T 3B20, DEC VAX, Sun2s & Sun3s etc. However, it has not been
> ported to RISC based targets, such HP 800s. Furthermore, the documentation
> makes it clear that porting the Task Library to RISC based targets is very
> difficult and beyond the scope of the of the manual. I have studied the manual
> and come to the conclusion that it is well beyond my capability.
> 
> Has anyone out there ported the AT&T C++ Task Library to an HP 800 series
> target? I should be most grateful for any assistance.
> 
> Thanks in advance, Jeff Pitchers Loughborough University.
> 
> E-Mail: J.R.Pitchers@uk.ac.lut (JANET)

I have not ported the task library to an HP RISC but I have ported it
to a sun 4 (SPARC).  Sun 4 os provides support for lightweight processes
(LWPs).  I used these as a basis for creation and scheduling of C++
tasks.  If the HP os provides threads or LWPs, then you may be able to
do a similar port.

Basically, what I did was to make every C++ task a LWP.  I got rid of
the C++ task scheduler because the LWP system provides its own scheduler.
The LWP system provides an inter-LWP communication facility but I elected to port the qhead and qtail classes provided in the task library.

The resulting library has the same classes (except for the scheduler) and interfaces as the original AT&T release, except for the minor point that each task must define a void main() as the task entry point (rather than the task's constructor).

The port took a couple of days, which included learning enough about
the task library and the LWP system to write the code (which turned out
to be a minor effort).

Hope this helps.

Bob Lund