147c6ae99SBarry Smith 247c6ae99SBarry Smith /* 347c6ae99SBarry Smith Code for manipulating distributed regular arrays in parallel. 447c6ae99SBarry Smith */ 547c6ae99SBarry Smith 6af0996ceSBarry Smith #include <petsc/private/dmdaimpl.h> /*I "petscdmda.h" I*/ 7d78e899eSRichard Tran Mills extern PetscErrorCode DMLocalToLocalCreate_DA(DM); 847c6ae99SBarry Smith 947c6ae99SBarry Smith /*@C 10bd1fc5aeSBarry Smith DMDAGetScatter - Gets the global-to-local, and 1147c6ae99SBarry Smith local-to-local vector scatter contexts for a distributed array. 1247c6ae99SBarry Smith 13d083f849SBarry Smith Collective on da 1447c6ae99SBarry Smith 1547c6ae99SBarry Smith Input Parameter: 1647c6ae99SBarry Smith . da - the distributed array 1747c6ae99SBarry Smith 1847c6ae99SBarry Smith Output Parameters: 19bd1fc5aeSBarry Smith + gtol - global-to-local scatter context (may be NULL) 200298fd71SBarry Smith - ltol - local-to-local scatter context (may be NULL) 2147c6ae99SBarry Smith 2247c6ae99SBarry Smith Level: developer 2347c6ae99SBarry Smith 2447c6ae99SBarry Smith Notes: 2547c6ae99SBarry Smith The output contexts are valid only as long as the input da is valid. 2647c6ae99SBarry Smith If you delete the da, the scatter contexts will become invalid. 2747c6ae99SBarry Smith 28db781477SPatrick Sanan .seealso: `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()` 2947c6ae99SBarry Smith @*/ 309371c9d4SSatish Balay PetscErrorCode DMDAGetScatter(DM da, VecScatter *gtol, VecScatter *ltol) { 3147c6ae99SBarry Smith DM_DA *dd = (DM_DA *)da->data; 3247c6ae99SBarry Smith 3347c6ae99SBarry Smith PetscFunctionBegin; 34a9a02de4SBarry Smith PetscValidHeaderSpecificType(da, DM_CLASSID, 1, DMDA); 3547c6ae99SBarry Smith if (gtol) *gtol = dd->gtol; 3647c6ae99SBarry Smith if (ltol) { 37*48a46eb9SPierre Jolivet if (!dd->ltol) PetscCall(DMLocalToLocalCreate_DA(da)); 3847c6ae99SBarry Smith *ltol = dd->ltol; 3947c6ae99SBarry Smith } 4047c6ae99SBarry Smith PetscFunctionReturn(0); 4147c6ae99SBarry Smith } 42