Newsgroups: comp.parallel.pvm
From: rory@chemeng.ed.ac.uk (Rory Mckinnel)
Subject: Re: Once more: Signals & PVM
Organization: Edinburgh University Chemical Engineering Department
Date: 22 Feb 1995 08:13:16 -0000
Message-ID: <3ierms$cdd@ling.chemeng.ed.ac.uk>


In article <3hqbgh$al2@zeus.rbi.informatik.uni-frankfurt.de>, sth@em.informatik.uni-frankfurt.de (Stefan Hoereth) writes:
>In article al2@zeus.rbi.informatik.uni-frankfurt.de, sth@em.informatik.uni-frankfurt.de (Stefan Hoereth) writes:
>
>> In pvm 3.3.6 and 3.3.7 there is no function call
>> 'pvm_signal()' (neither in 'pvm3.h' nor in the sources)
>
>Of course not, since the name of the function call is 'pvm_sendsig()'.
>
>I have to excuse for my 'garbage mail' but I was misled
>by another article.
>
>However, people seem to be undecided whether to use signals with pvm or not.
>
>To my understanding it should be save to:
>  - use a dedicated user signal (e.g. SIGUSR1 on SUN)
>  - mask this signal before every call to a pvm routine.
>(Is the latter really necessary?)
>

I believe that you have to worry about more than just the PVM functions.
Functions such as malloc() will not be re-entrant either. I remember
from using one package, that SIGALRM was used to check for messages during
program execution. To allow this it had to have its own versions of all the 
memory allocation functions built into the comms library to prevent
such re-entrant problems.
	
Rory.







-- 
Dr Rory McKinnel,                          | Email: R.McKinnel@Ed.Ac.Uk
The Department of Chemical Engineering,    | Tel  : +44 (0)131 650 5891
University of Edinburgh, King's Buildings, | Fax  : +44 (0)131 650 6551
Mayfield Road, Edinburgh, Scotland EH9 3JL.| WWW  : http://www.chemeng.ed.ac.uk

