ABSTRACT
Message Passing Interface (MPI) is the abbreviation for message passing interface. It consists of a library of Fortran subroutines that the programmer calls explicitly to write parallel programs. A parallel computation, using MPI routines, is performed by a number of processors, each having its own local memory to execute the task assigned to it and communicate with each other through messages. Except for mpi_wtime and mpi_wtick, all MPI Fortran routines return an integer error value. This is the last argument of all Fortran subroutines. MPI version and subversion can be obtained in two ways. The named integer constants mpi_version and mpi_subversion contain the version and subversion of mpi being used by the system. Internally MPI maintains it own data structure that the programmer can access through an MPI handle. Many MPI routines use these handles as arguments both for input and output operations. In Fortran, the handles are usually integer constants or integer arrays.
