Provided by: mpich-doc_3.3~a2-4_all 

NAME
MPI_Init - Initialize the MPI execution environment
SYNOPSIS
int MPI_Init( int *argc, char ***argv )
INPUT PARAMETERS
argc - Pointer to the number of arguments
argv - Pointer to the argument vector
THREAD AND SIGNAL SAFETY
This routine must be called by one thread only. That thread is called the main thread and must be the
thread that calls MPI_Finalize .
NOTES
The MPI standard does not say what a program can do before an MPI_INIT or after an MPI_FINALIZE . In the
MPICH implementation, you should do as little as possible. In particular, avoid anything that changes
the external state of the program, such as opening files, reading standard input or writing to standard
output.
NOTES FOR C
As of MPI-2, MPI_Init will accept NULL as input parameters. Doing so will impact the values stored in
MPI_INFO_ENV .
NOTES FOR FORTRAN
The Fortran binding for MPI_Init has only the error return
subroutine MPI_INIT( ierr )
integer ierr
ERRORS
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. Before the value is returned, the current MPI error
handler is called. By default, this error handler aborts the MPI job. The error handler may be changed
with MPI_Comm_set_errhandler (for communicators), MPI_File_set_errhandler (for files), and
MPI_Win_set_errhandler (for RMA windows). The MPI-1 routine MPI_Errhandler_set may be used but its use
is deprecated. The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be
returned. Note that MPI does not guarentee that an MPI program can continue past an error; however, MPI
implementations will attempt to continue whenever possible.
MPI_SUCCESS
- No error; MPI routine completed successfully.
MPI_ERR_OTHER
- This error class is associated with an error code that indicates that an attempt was made to
call MPI_INIT a second time. MPI_INIT may only be called once in a program.
SEE ALSO
MPI_Init_thread, MPI_Finalize
11/12/2016 MPI_Init(3)