MPI_Finalize(3OpenMPI)													    MPI_Finalize(3OpenMPI)

NAME

       MPI_Finalize  - Terminates MPI execution environment.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Finalize()

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_FINALIZE(IERROR)
	    INTEGER   IERROR

C++ Syntax
       #include <mpi.h>
       void Finalize()

OUTPUT PARAMETER

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       This  routine  cleans  up  all  MPI  states.  Once  this  routine  is  called, no MPI routine (not even MPI_Init) may be called, except for
       MPI_Get_version, MPI_Initialized, and MPI_Finalized. Unless there has been a call to MPI_Abort, you must ensure that all pending communica-
       tions  involving  a process are complete before the process calls MPI_Finalize. If the call returns, each process may either continue local
       computations or exit without participating in further communication with other processes.  At  the  moment  when  the  last  process  calls
       MPI_Finalize, all pending sends must be matched by a receive, and all pending receives must be matched by a send.

       MPI_Finalize  is  collective over all connected processes. If no processes were spawned, accepted, or connected, then this means it is col-
       lective over MPI_COMM_WORLD. Otherwise, it is collective over the union of all processes that have been and continue to be connected.

NOTES

       All processes must call this routine before exiting. All processes will still exist but may not make any further  MPI  calls.  MPI_Finalize
       guarantees  that  all  local  actions  required	by  communications the user has completed will, in fact, occur before it returns. However,
       MPI_Finalize guarantees nothing about pending communications that have  not  been  completed;  completion  is  ensured  only  by  MPI_Wait,
       MPI_Test, or MPI_Request_free combined with some other verification of completion.

       For  example, a successful return from a blocking communication operation or from MPI_Wait or MPI_Test means that the communication is com-
       pleted by the user and the buffer can be reused, but does not guarantee that the local process has no more work to do.  Similarly,  a  suc-
       cessful	return	from MPI_Request_free with a request handle generated by an MPI_Isend nullifies the handle but does not guarantee that the
       operation has completed. The MPI_Isend is complete only when a matching receive has completed.

       If you would like to cause actions to happen when a process finishes, attach an attribute to MPI_COMM_SELF with a callback function.  Then,
       when MPI_Finalize is called, it will first execute the equivalent of an MPI_Comm_free on MPI_COMM_SELF. This will cause the delete callback
       function to be executed on all keys associated with MPI_COMM_SELF in an arbitrary order. If no key has been attached to MPI_COMM_SELF, then
       no  callback  is invoked. This freeing of MPI_COMM_SELF happens before any other parts of MPI are affected. Calling MPI_Finalized will thus
       return "false" in any of these callback functions. Once you have done this with MPI_COMM_SELF, the results of MPI_Finalize are  not  speci-
       fied.

ERRORS

       Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ func-
       tions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception  mechanism
       will be used to throw an MPI:Exception object.

       Before  the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN  may	be
       used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

Open MPI 1.2							  September 2006					    MPI_Finalize(3OpenMPI)