starpu-max/tests/datawizard/acquire_release.c

/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 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 ntasks = 10000;

#ifdef STARPU_USE_CUDA
extern void increment_cuda(void *descr[], __attribute__ ((unused)) void *_args);
#endif

void increment_cpu(void *descr[], __attribute__ ((unused)) void *_args)
{
	unsigned *tokenptr = (unsigned *)STARPU_VARIABLE_GET_PTR(descr[0]);
	(*tokenptr)++;
}

static struct starpu_codelet increment_cl = {
        .where = STARPU_CPU|STARPU_CUDA,
	.cpu_funcs = {increment_cpu, NULL},
#ifdef STARPU_USE_CUDA
	.cuda_funcs = {increment_cuda, NULL},
#endif
	.nbuffers = 1
};

unsigned token = 0;
starpu_data_handle_t token_handle;

int increment_token()
{
	struct starpu_task *task = starpu_task_create();
        task->synchronous = 1;
	task->cl = &increment_cl;
	task->buffers[0].handle = token_handle;
	task->buffers[0].mode = STARPU_RW;
	return starpu_task_submit(task);
}

void callback(void *arg __attribute__ ((unused)))
{
        starpu_data_release(token_handle);
}

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

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

	starpu_variable_data_register(&token_handle, 0, (uintptr_t)&token, sizeof(unsigned));

        FPRINTF(stderr, "Token: %u\n", token);

	for(i=0; i<ntasks; i++)
	{
		/* synchronize data in RAM */
                ret = starpu_data_acquire(token_handle, STARPU_R);
		STARPU_CHECK_RETURN_VALUE(ret, "starpu_data_acquire");

                token ++;
                starpu_data_release(token_handle);

                ret = increment_token();
		if (ret == -ENODEV) goto enodev;
		STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_submit");

                ret = starpu_data_acquire_cb(token_handle, STARPU_RW, callback, NULL);
		STARPU_CHECK_RETURN_VALUE(ret, "starpu_data_acquire_cb");
	}

	starpu_data_unregister(token_handle);

        FPRINTF(stderr, "Token: %u\n", token);
        STARPU_ASSERT(token==ntasks*2);

	starpu_shutdown();

	return EXIT_SUCCESS;

enodev:
	starpu_data_unregister(token_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 STARPU_TEST_SKIPPED;
}