mg2d: add support for MPI-based multi-component solves

For the moment, only the finest component is distributed, any coarser
levels are gathered to rank 0. That should change in the future.

1 files changed, 16 insertions, 0 deletions

diff --git a/mg2d.h b/mg2d.h
index fd11906..1db4ace 100644
--- a/mg2d.h
+++ b/mg2d.h
@@ -22,6 +22,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include <mpi.h>
+
 #include "mg2d_boundary.h"
 #include "mg2d_constants.h"
 
@@ -168,6 +170,20 @@ typedef struct MG2DContext {
  * @return The solver context on success, NULL on failure.
  */
 MG2DContext *mg2d_solver_alloc(size_t domain_size);
+
+/**
+ * Allocate a solver component in a multi-component MPI-based solve.
+ *
+ * @param comm The MPI communicator used to communicate with the other
+ *             components.
+ * @param local_start Indices of this component's lower left corner in the full
+ *                    computational domain.
+ * @param local_size Size of this component in each direction.
+ *
+ * @return The solver context on success, NULL on failure.
+ */
+MG2DContext *mg2d_solver_alloc_mpi(MPI_Comm comm, const size_t local_start[2],
+                                   const size_t local_size[2]);
 /**
  * Solve the equation, after all the required fields have been filled by the
  * caller.