MPI_Group_size(3) Open MPI MPI_Group_size(3)NAMEMPI_Group_size - Returns the size of a group.
SYNTAXC 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).
DESCRIPTIONMPI_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.
1.7.4 Feb 04, 2014 MPI_Group_size(3)
