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
- 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++ 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.