osx man page for mpi_comm_free

MPI_Comm_free(3OpenMPI) 												   MPI_Comm_free(3OpenMPI)

NAME
       MPI_Comm_free  - Mark a communicator object for deallocation.

SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Comm_free(MPI_Comm *comm)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_COMM_FREE(COMM, IERROR)
	    INTEGER   COMM, IERROR

C++ Syntax
       #include <mpi.h>
       void Comm::Free()

INPUT PARAMETER
       comm	 Communicator to be destroyed (handle).

OUTPUT PARAMETER
       IERROR	 Fortran only: Error status (integer).

DESCRIPTION
       This  operation	marks  the  communicator object for deallocation. The handle is set to MPI_COMM_NULL. Any pending operations that use this
       communicator will complete normally; the object is actually deallocated only if there are no other  active  references  to  it.	This  call
       applies	to  intracommunicators	and  intercommunicators. Upon actual deallocation, the delete callback functions for all cached attributes
       (see Section 5.7 in the MPI-1 Standard, "Caching") are called in arbitrary order.

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_Comm_free(3OpenMPI)