MPI_Init

MPI_Init - Initialize the MPI execution environment

SYNOPSIS

 
#include <mpi.h> 
int MPI_Init(int *pargc, char ***pargv)

INPUT PARAMETERS

NOTES

MPI specifies no command-line arguments but does allow an MPI implementation to make use of them. csWMPI II II neither uses nor adds any values to the argc and argv parameters.

MPI mandates that the same thread must call MPI_Init or MPI_Init_thread and MPI_Finalize.

Note that the Fortran binding for this routine has only the error return argument (MPI_INIT(ierror)).

Because the Fortran and C versions of MPI_Init are different, there is a restriction on who can call MPI_Init. The version (Fortran or C) must match the main program. That is, if the main program is in C, then the C version of MPI_Init must be called. If the main program is in Fortran, the Fortran version must be called.

ERRORS

If an error occurs in an MPI function, the current MPI error handler is called to handle it. By default, this error handler aborts the MPI job. The error handler may be changed with MPI_Errhandler_set; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned (in C and Fortran; this error handler is less useful in with the C++ MPI bindings. The predefined error handler MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value needs to be recovered). Note that MPI does not guarantee that an MPI program can continue past an error.

All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value; C routines as the value of the function and Fortran routines in the last argument. The C++ bindings for MPI do not return error values; instead, error values are communicated by throwing exceptions of type MPI::Exception (but not by default). Exceptions are only thrown if the error value is not MPI::SUCCESS.

Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return upon an error, there will be no way to recover what the actual error value was.