PetscSFBcastBegin#

begin pointwise broadcast with root value being reduced to leaf value, to be concluded with call to PetscSFBcastEnd()

Synopsis#

#include "petscsf.h" 
PetscErrorCode PetscSFBcastBegin(PetscSF sf, MPI_Datatype unit, const void *rootdata, void *leafdata, MPI_Op op)

Collective

Input Parameters#

sf - star forest on which to communicate
unit - data type associated with each node
rootdata - buffer to broadcast
op - operation to use for reduction

Output Parameter#

leafdata - buffer to be reduced with values from each leaf’s respective root

Note#

When PETSc is configured with device support, it will use its own mechanism to figure out whether the given data pointers are host pointers or device pointers, which may incur a noticeable cost. If you already knew the info, you should use PetscSFBcastWithMemTypeBegin() instead.