starpu-max/tests/datawizard/readers_and_writers.c

/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2009, 2010  Université de Bordeaux 1
 * Copyright (C) 2010, 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 <starpu.h>
#include "../common/helper.h"

static unsigned book = 0;
static starpu_data_handle book_handle;

static void dummy_kernel(void *descr[], void *arg)
{
}

static starpu_codelet rw_cl = {
	.where = STARPU_CPU|STARPU_CUDA|STARPU_OPENCL,
	.cuda_func = dummy_kernel,
	.cpu_func = dummy_kernel,
	.opencl_func = dummy_kernel,
	.nbuffers = 1
};

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

	ret = starpu_init(NULL);
	STARPU_CHECK_RETURN_VALUE(ret, "starpu_init");

	/* initialize the resource */
	starpu_vector_data_register(&book_handle, 0, (uintptr_t)&book, 1, sizeof(unsigned));

	unsigned ntasks = 16*1024;

	unsigned t;
	for (t = 0; t < ntasks; t++)
	{
		struct starpu_task *task = starpu_task_create();

		task->cl = &rw_cl;

		/* we randomly select either a reader or a writer (give 10
		 * times more chances to be a reader) */
		task->buffers[0].mode = ((rand() % 10)==0)?STARPU_W:STARPU_R;
		task->buffers[0].handle = book_handle;

		int ret = starpu_task_submit(task);
		if (ret == -ENODEV) goto enodev;
		STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_submit");
	}

	ret = starpu_task_wait_for_all();
	STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_wait_for_all");

	starpu_data_unregister(book_handle);
	starpu_shutdown();

	return 0;

enodev:
	starpu_data_unregister(book_handle);
	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 */
	starpu_shutdown();
	return 77;
}