From: Joachim Worringen Newsgroups: comp.parallel.mpi Subject: Re: How to declare shared variable in MPICH Date: Fri, 30 Oct 1998 09:33:56 +0100 Organization: Chair for Operating Systems, RWTH Aachen Message-Id: <363979F4.8457FE87@lfbs.rwth-aachen.de> References: <35F792A6.41C6@epfl.ch> <199809161118.HAA14384@volitans.MorningStar.Com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Preuk S. wrote: > > Dear, > > Generally, each process in MPICH has its own accessiable. When any > variables are accessed by any processes, the value of the same variable of > other processes have not been changed. I would like to use shared variable > that its value has been changed, when it is accessed by any processes. How > should I declare these shared variables? The message-passing programming model does not use shared variables, thus you cant declare one with MPICH (and any other MPI-Implementation). Depending on you hardware, you can use some kind of shared memory environment. You might take a look at http://www.lfbs.rwth-aachen.de/~karsten/projects/SVMlib for a library supplying virtual shared memory on Unix and Windows NT (based on TCP/IP-communication). Joachim -- ---------------------------------------------------------------------------- | _ : Joachim Worringen, Lehrstuhl fuer Betriebssysteme |_|_`__ : RWTH Aachen, Kopernikusstr. 16, D-52056 Aachen | |__) : Tel. : +49-241/80-7609 | Fax : +49-241/8888-339 |__)S : e-Mail : joachim@lfbs.rwth-aachen.de