Newsgroups: comp.parallel.mpi From: Erik Demaine Subject: Re: MPI_Request structure Organization: University of Waterloo Date: Tue, 3 Jun 1997 12:18:08 GMT Message-ID: Andrei Malevsky wrote: : Does anyone know how to dereference (read) a MPI_Request : structure used for nonblocking communications? : It is not user-visible, but we have a problem debugging : a code where this structure gets corrupted and we would : love to know where and how it happens. It depends on the implementation. Which one are you using? I've done this before with CHIMP once, where it turns out MPI_Cancel was corrupting the MPI_Request structure. The structure is usually not opaque. Take a look at your mpi.h file. I guess that implementations satisfying MPI 1.1 might make MPI_Request into a funny number that references into a table. In that case, look at the source for say MPI_Test and figure out how to check things yourself with the debugger. You might also consider calling some of the query operations to (portably) get information in the request structure. Good luck, Erik -- Erik Demaine () e-mail: eddemain@daisy.uwaterloo.ca Dept. of Computer Science || URL: http://daisy.uwaterloo.ca/~eddemain/ University of Waterloo || PGP key: finger me. "Maturity is switching Waterloo, ON Canada N2L 3G1 () from passive voice to active voice" -P. Alder