Newsgroups: comp.parallel.mpi From: Wolfram Webers Subject: Re: sending various datatypes in MPI Organization: TU-Berlin Date: Thu, 07 May 1998 09:44:29 +0200 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <3551665D.548B9A9D@cs.tu-berlin.de> Ben Kao wrote: > Forgive me if this is a silly question, but I can't figure out how to > send datatypes which do not fall into the standard MPI_INT, MPI_CHAR, > etc datatypes. Thus, for example, how would one go about sending > something which is defined as a C++ class? > > Thanks, > > - ben > bkao@eecs.uic.edu Normally all C++ classes are bases on atomic C-Datatypes that are supported by MPI. All you have to do is to create member-functions pack/unpack/packsize in your class your want to communicate. This functions must code the class-entries into a byte-buffer (or in a structure defined by MPI_Type_struct). On recursiv datatypes the construction of the buffer must be resursiv, too. But this is not a problem if you create a base-class with the three member functions an overload them in all inherited classes. Ciao, Wolfram.