/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2010  Université de Bordeaux 1
 * Copyright (C) 2010  Mehdi Juhoor <mjuhoor@gmail.com>
 * Copyright (C) 2010  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 <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <starpu.h>
#include <stdlib.h>

#define NITER		1000
#define VECTORSIZE	1024

float *buffer;

starpu_data_handle v_handle;

static void dummy_codelet(void *descr[], __attribute__ ((unused)) void *_args)
{
}

static starpu_codelet cl = {
	.where = STARPU_CPU|STARPU_CUDA|STARPU_OPENCL,
	.cpu_func = dummy_codelet,
#ifdef STARPU_USE_CUDA
	.cuda_func = dummy_codelet,
#endif
#ifdef STARPU_USE_OPENCL
	.opencl_func = dummy_codelet,
#endif
	.nbuffers = 1
};

int use_handle(starpu_data_handle handle)
{
	int ret;
	struct starpu_task *task;

	task = starpu_task_create();
		task->cl = &cl;
		task->buffers[0].handle = handle;
		task->buffers[0].mode = STARPU_RW;
		task->detach = 0;

	ret = starpu_task_submit(task);

	return ret;
}

int main(int argc, char **argv)
{
	int ret;

	starpu_init(NULL);

	starpu_data_malloc_pinned_if_possible((void **)&buffer, VECTORSIZE);

	starpu_vector_data_register(&v_handle, 0, (uintptr_t)buffer, VECTORSIZE, sizeof(char));

	struct starpu_data_filter f = {
		.filter_func = starpu_vector_divide_in_2_filter_func,
		/* there are only 2 children */
		.nchildren = 2,
		/* the length of the first part */
		.filter_arg = VECTORSIZE/2,
		.get_nchildren = NULL,
		.get_child_ops = NULL
	};

	unsigned iter;
	for (iter = 0; iter < NITER; iter++)
	{
		starpu_data_map_filters(v_handle, 1, &f);
	
		ret = use_handle(starpu_data_get_sub_data(v_handle, 1, 0));
		if (ret == -ENODEV)
			goto enodev;
	
		ret = use_handle(starpu_data_get_sub_data(v_handle, 1, 1));
		if (ret == -ENODEV)
			goto enodev;
	
		starpu_task_wait_for_all();
	
		starpu_data_unpartition(v_handle, 0);
	
		ret = use_handle(v_handle);
		if (ret == -ENODEV)
			goto enodev;
	
		starpu_task_wait_for_all();
	}

	starpu_data_unregister(v_handle);

	starpu_shutdown();

	return 0;

enodev:
	fprintf(stderr, "WARNING: No one can execute this task\n");
	/* yes, we do not perform the computation but we did detect that no one
 	 * could perform the kernel, so this is not an error from StarPU */
	return 0;
}
