oracular (3) MPI_Comm_free.openmpi.3.gz

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

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_COMM_FREE(COMM, IERROR)
            INTEGER   COMM, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Comm_free(comm, ierror)
            TYPE(MPI_Comm), INTENT(INOUT) :: comm
            INTEGER, OPTIONAL, INTENT(OUT) :: 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.

NOTES

       Note  that it is not defined by the MPI standard what happens if the delete_fn callback invokes other MPI
       functions.  In Open MPI, it is not valid for delete_fn callbacks (or any of their  children)  to  add  or
       delete attributes on the same object on which the delete_fn callback is being invoked.

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++ functions 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.

SEE ALSO

       MPI_Comm_delete_attr