NAME

MPI_Group_intersection - The set intersection between two groups

SYNOPSIS

#include <mpi.h> 
int MPI_Group_intersection(MPI_Group g1 , MPI_Group g2 , MPI_Group *out ); 
#include <pmpi.h> 
int PMPI_Group_intersection(MPI_Group g1 , MPI_Group g2 , MPI_Group *out ); 

INPUT PARAMETERS

g1 - group (handle)

g2 - group (handle)

OUTPUT PARAMETER

out - the resulting intersection group (handle).

DESCRIPTION

The MPI_Group_intersection() function is used to construct a new group out that is the set intersection between the two groups g1 and g2 .

i.e. The processes in the new group will be those in g1 and also in g2 .

If the new group is empty then MPI_GROUP_EMPTY is returned in out .

The new group returned should eventually be freed with the MPI_Group_free() function. Note that the groups must be valid (not MPI_GROUP_NULL). PMPI_Group_intersection() is the profiling version of this function.

ERRORS

All MPI routines except for MPI_Wtime and MPI_Wtick return an error value. The the current MPI error handler is invoked if this return value is not MPI_SUCCESS. The default error handler aborts, but this may be changed with by using the MPI_Errhandler_set() function. The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned instead. Note that MPI does not guarentee that an MPI program can continue past an error. In this implementation, all errors except MPI_ERR_INTERN or MPI_ERR_OTHER should always be recoverable.

MPI_SUCCESS - No error;

MPI_ERR_GROUP - Invalid group;

MPI_ERR_ARG - Invalid output pointer;

MPI_ERR_INTERN - Out of Memory, cannot create a new group.

SEE ALSO

MPI_Group_free (3) MPI_Group_difference (3) MPI_Group_excl (3) MPI_Group_range_excl (3) MPI_Group_range_incl (3) MPI_Group_union (3)

• Lockless
• MPI Documentation
• MPI_Group_intersection