Open MPI logo

MPI_Group_size(3) man page (version 1.3.4)

  |   Home   |   Support   |   FAQ   |  

« Return to documentation listing



NAME

       MPI_Group_size - Returns the size of a group.

SYNTAX


C Syntax

       #include <mpi.h>
       int MPI_Group_size(MPI_Group group, int *size)

Fortran Syntax

       INCLUDE 'mpif.h'
       MPI_GROUP_SIZE(GROUP, SIZE, IERROR)
            INTEGER   GROUP, SIZE, IERROR

C++ Syntax

       #include <mpi.h>
       int Group::Get_size() const

INPUT PARAMETERS

       group     Group (handle).

OUTPUT PARAMETERS

       size      Number of processes in the group (integer).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_Group_size  returns  in  size the number of processes in the group.
       Thus, if group = MPI_GROUP_EMPTY, then the call will return size  =  0.
       On the other hand, a call with group = MPI_GROUP_NULL is erroneous.

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.

1.3.4                            Nov 11, 2009                MPI_Group_size(3)

« Return to documentation listing