Actual source code: dascatter.c
petsc-3.6.1 2015-08-06
2: /*
3: Code for manipulating distributed regular arrays in parallel.
4: */
6: #include <petsc/private/dmdaimpl.h> /*I "petscdmda.h" I*/
7: extern PetscErrorCode DMLocalToLocalCreate_DA(DM);
11: /*@C
12: DMDAGetScatter - Gets the global-to-local, and
13: local-to-local vector scatter contexts for a distributed array.
15: Collective on DMDA
17: Input Parameter:
18: . da - the distributed array
20: Output Parameters:
21: + gtol - global-to-local scatter context (may be NULL)
22: - ltol - local-to-local scatter context (may be NULL)
24: Level: developer
26: Notes:
27: The output contexts are valid only as long as the input da is valid.
28: If you delete the da, the scatter contexts will become invalid.
30: .keywords: distributed array, get, scatter, context, global-to-local,
31: local-to-global, local-to-local
33: .seealso: DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMLocalToGlobalBegin()
34: @*/
35: PetscErrorCode DMDAGetScatter(DM da,VecScatter *gtol,VecScatter *ltol)
36: {
38: DM_DA *dd = (DM_DA*)da->data;
42: if (gtol) *gtol = dd->gtol;
43: if (ltol) {
44: if (!dd->ltol) {
45: DMLocalToLocalCreate_DA(da);
46: }
47: *ltol = dd->ltol;
48: }
49: return(0);
50: }