/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2011-2020  Université de Bordeaux, CNRS (LaBRI UMR 5800), Inria
 *
 * 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 "../helper.h"

/*
 * Test writing back the result into main memory as soon as it is available
 */

static unsigned var = 0;
static starpu_data_handle_t handle;
/*
 *	Increment codelet
 */

#ifdef STARPU_USE_OPENCL
/* dummy OpenCL implementation */
static void increment_opencl_kernel(void *descr[], void *cl_arg)
{
	(void)cl_arg;
	STARPU_SKIP_IF_VALGRIND;

	cl_mem d_token = (cl_mem)STARPU_VARIABLE_GET_PTR(descr[0]);
	unsigned h_token;

	cl_command_queue queue;
	starpu_opencl_get_current_queue(&queue);

	clEnqueueReadBuffer(queue, d_token, CL_TRUE, 0, sizeof(unsigned), (void *)&h_token, 0, NULL, NULL);
	h_token++;
	clEnqueueWriteBuffer(queue, d_token, CL_TRUE, 0, sizeof(unsigned), (void *)&h_token, 0, NULL, NULL);
}
#endif


#ifdef STARPU_USE_CUDA
static void increment_cuda_kernel(void *descr[], void *cl_arg)
{
	(void)cl_arg;
	STARPU_SKIP_IF_VALGRIND;

	unsigned *tokenptr = (unsigned *)STARPU_VARIABLE_GET_PTR(descr[0]);
	unsigned host_token;

	/* This is a dummy technique of course */
	cudaMemcpyAsync(&host_token, tokenptr, sizeof(unsigned), cudaMemcpyDeviceToHost, starpu_cuda_get_local_stream());
	cudaStreamSynchronize(starpu_cuda_get_local_stream());

	host_token++;

	cudaMemcpyAsync(tokenptr, &host_token, sizeof(unsigned), cudaMemcpyHostToDevice, starpu_cuda_get_local_stream());
}
#endif

void increment_cpu_kernel(void *descr[], void *cl_arg)
{
	(void)cl_arg;
	STARPU_SKIP_IF_VALGRIND;

	unsigned *tokenptr = (unsigned *)STARPU_VARIABLE_GET_PTR(descr[0]);
	*tokenptr = *tokenptr + 1;
}

static struct starpu_codelet increment_cl =
{
#ifdef STARPU_USE_CUDA
	.cuda_funcs = {increment_cuda_kernel},
	.cuda_flags = {STARPU_CUDA_ASYNC},
#endif
#ifdef STARPU_USE_OPENCL
	.opencl_funcs = {increment_opencl_kernel},
	.opencl_flags = {STARPU_OPENCL_ASYNC},
#endif
	.cpu_funcs = {increment_cpu_kernel},
	.cpu_funcs_name = {"increment_cpu_kernel"},
	.nbuffers = 1,
	.modes = {STARPU_RW}
};

int main(void)
{
	int ret;

	ret = starpu_init(NULL);
	if (ret == -ENODEV) return STARPU_TEST_SKIPPED;
	STARPU_CHECK_RETURN_VALUE(ret, "starpu_init");

	starpu_variable_data_register(&handle, STARPU_MAIN_RAM, (uintptr_t)&var, sizeof(unsigned));

	/* Copy the handle in main memory every time it is modified */
	uint32_t wt_mask = (1<<STARPU_MAIN_RAM);
	starpu_data_set_wt_mask(handle, wt_mask);

#ifdef STARPU_QUICK_CHECK
	unsigned ntasks = 32;
	unsigned nloops = 4;
#else
	unsigned ntasks = 1024;
	unsigned nloops = 16;
#endif

	unsigned loop;
	unsigned t;

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

		task->cl = &increment_cl;
		task->handles[0] = handle;

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

	starpu_data_unregister(handle);

	ret = EXIT_SUCCESS;
	if (var != ntasks*nloops)
	{
		ret = EXIT_FAILURE;
		FPRINTF(stderr, "VAR is %u should be %u\n", var, ntasks);
	}

	starpu_shutdown();

	STARPU_RETURN(ret);

enodev:
	starpu_data_unregister(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;
}