/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2011  Centre National de la Recherche Scientifique
 *
 * StarPU is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at
 * your option) any later version.
 *
 * StarPU is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU Lesser General Public License in COPYING.LGPL for more details.
 */

#include <mpi.h>
#include <starpu.h>
#include <starpu_mpi.h>

int starpu_mpi_scatter_detached(starpu_data_handle_t *data_handles, int count, int root, MPI_Comm comm)
{
	int rank;
	int x;

	MPI_Comm_rank(comm, &rank);

	for(x = 0; x < count ;  x++)
	{
		if (data_handles[x])
		{
			int owner = starpu_data_get_rank(data_handles[x]);
			int mpi_tag = starpu_data_get_tag(data_handles[x]);
			STARPU_ASSERT(mpi_tag >= 0);
			if ((rank == root) && (owner != root))
			{
				//fprintf(stderr, "[%d] Sending data[%d] to %d\n", rank, x, owner);
				starpu_mpi_isend_detached(data_handles[x], owner, mpi_tag, comm, NULL, NULL);
			}
			if ((rank != root) && (owner == rank))
			{
				//fprintf(stderr, "[%d] Receiving data[%d] from %d\n", rank, x, root);
				starpu_mpi_irecv_detached(data_handles[x], root, mpi_tag, comm, NULL, NULL);
			}
		}
	}
	return 0;
}

int starpu_mpi_gather_detached(starpu_data_handle_t *data_handles, int count, int root, MPI_Comm comm)
{
	int rank;
	int x;

	MPI_Comm_rank(comm, &rank);

	for(x = 0; x < count ;  x++)
	{
		if (data_handles[x])
		{
			int owner = starpu_data_get_rank(data_handles[x]);
			int mpi_tag = starpu_data_get_tag(data_handles[x]);
			STARPU_ASSERT(mpi_tag >= 0);
			if ((rank == root) && (owner != root))
			{
				//fprintf(stderr, "[%d] Receiving data[%d] from %d\n", rank, x, owner);
				starpu_mpi_irecv_detached(data_handles[x], owner, mpi_tag, comm, NULL, NULL);
			}
			if ((rank != root) && (owner == rank))
			{
				//fprintf(stderr, "[%d] Sending data[%d] to %d\n", rank, x, root);
				starpu_mpi_isend_detached(data_handles[x], root, mpi_tag, comm, NULL, NULL);
			}
		}
	}
	return 0;
}