NAME

MPI_Init - Initialize the MPI library

SYNOPSIS

#include <mpi.h> 
int MPI_Init(int *argc , char ***argv ); 
#include <pmpi.h> 
int PMPI_Init(int *argc , char ***argv ); 

INPUT PARAMETERS

argc - argc count of command line arguments (integer)

argv - argv value of command line arguments (integer)

DESCRIPTION

The MPI_Init() function is used to initialize MPI. Prior to its use, no MPI functions may be used other than MPI_Initialized(). This function must not be called twice.

The arguments to this function should be the command-line arguments given to the main() function of the program using MPI. This version of MPI does not alter or use any command line arguments, but does invoke main() again in seperate threads as a part of the startup process, which uses these values. If argc or argv are invalid, then ranks other than the root rank of MPI_COMM_WORLD will not be able to access command-line arguments.

PMPI_Init() is the profiling version of this function.

EXTRA FUNCTIONS

This version of MPI implements the MPI 1.3 specification. However, some functions from MPI 2.0 are also implemented. In addition, some functions used to control the amount of internal buffering are exposed. See MPI_bufcopy_set (3) and MPI_bufcopy_get(3).

SIGNALS USED

This version of MPI uses a low-priority real-time signal in order to progress sends. Signals are blocked in the I/O threads. However, since this MPI library implements ranks as threads, use pthread_sigmask() and pthread_kill() if you wish to use signals. Otherwise the wrong ranks may handle a signal invocation.

ERRORS

All MPI routines except for MPI_Wtime and MPI_Wtick return an error value. The the current MPI error handler is invoked if this return value is not MPI_SUCCESS. The default error handler aborts, but this may be changed with by using the MPI_Errhandler_set() function. The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned instead. Note that MPI does not guarentee that an MPI program can continue past an error. In this implementation, all errors except MPI_ERR_INTERN or MPI_ERR_OTHER should always be recoverable.

MPI_SUCCESS - No error;

MPI_ERR_OTHER - MPI has already started or shut down.

SEE ALSO

MPI_Initialized (3) MPI_Finalize (3) MPI_Finalized (3) MPI_Abort (3) MPI_Get_version (3) MPI_Get_processor_name (3)

• Lockless
• MPI Documentation
• MPI_Init