starpu-max/tests/datawizard/critical_section_with_void_interface.c

/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2010  Université de Bordeaux 1
 *
 * 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>

starpu_data_handle void_handle;

int critical_var;

static void critical_section(void *descr[], __attribute__ ((unused)) void *_args)
{
	/* We do not protect this variable because it is only accessed when the
	 * "void_handle" piece of data is accessed. */
	critical_var++;
}

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

int main(int argc, char **argv)
{
	int ntasks = 1000;
	int ret;

#ifdef STARPU_SLOW_MACHINE
	ntasks /= 10;
#endif

	starpu_init(NULL);

	critical_var = 0;

	/* Create a void data which will be used as an exclusion mechanism. */
	starpu_void_data_register(&void_handle);

	int i;
	for (i = 0; i < ntasks; i++)
	{
		struct starpu_task *task = starpu_task_create();
			task->cl = &cl;
			task->buffers[0].handle = void_handle;
			task->buffers[0].mode = STARPU_RW;
	
		ret = starpu_task_submit(task);
		if (ret == -ENODEV)
			goto enodev;
	}

	starpu_data_unregister(void_handle);

	STARPU_ASSERT(critical_var == ntasks);

	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 77;
}