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/* StarPU --- Runtime system for heterogeneous multicore architectures.
*
* Copyright (C) 2010-2024 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.
*/
/*
* This example demonstrates how to use StarPU to scale an array by a factor.
* It shows how to manipulate data with StarPU's data management library.
* 1- how to declare a piece of data to StarPU (starpu_vector_data_register)
* 2- how to submit a task to StarPU
* 3- how a kernel can manipulate the data (buffers[0].vector.ptr)
*/
#include <starpu.h>
#define NX 2048
extern void vector_scal_cpu(void *buffers[], void *_args);
extern void vector_scal_cuda(void *buffers[], void *_args);
extern void vector_scal_opencl(void *buffers[], void *_args);
static struct starpu_codelet cl =
{
/* CPU implementation of the codelet */
.cpu_funcs = {vector_scal_cpu},
#ifdef STARPU_USE_CUDA
/* CUDA implementation of the codelet */
.cuda_funcs = {vector_scal_cuda},
#endif
#ifdef STARPU_USE_OPENCL
/* OpenCL implementation of the codelet */
.opencl_funcs = {vector_scal_opencl},
#endif
.nbuffers = 1,
.modes = {STARPU_RW}
};
#ifdef STARPU_USE_OPENCL
struct starpu_opencl_program programs;
#endif
int main(int argc, char **argv)
{
/* We consider a vector of float that is initialized just as any of C
* data */
float vector[NX];
unsigned i;
for (i = 0; i < NX; i++)
vector[i] = 1.0f;
fprintf(stderr, "BEFORE : First element was %f\n", vector[0]);
/* Initialize StarPU with default configuration */
int ret = starpu_init(NULL);
STARPU_CHECK_RETURN_VALUE(ret, "starpu_init");
#ifdef STARPU_USE_OPENCL
starpu_opencl_load_opencl_from_file("vector_scal_opencl_kernel.cl", &programs, NULL);
#endif
/* Tell StaPU to associate the "vector" vector with the "vector_handle"
* identifier. When a task needs to access a piece of data, it should
* refer to the handle that is associated to it.
* In the case of the "vector" data interface:
* - the first argument of the registration method is a pointer to the
* handle that should describe the data
* - the second argument is the memory node where the data (ie. "vector")
* resides initially: STARPU_MAIN_RAM stands for an address in main memory, as
* opposed to an address on a GPU for instance.
* - the third argument is the address of the vector in RAM
* - the fourth argument is the number of elements in the vector
* - the fifth argument is the size of each element.
*/
starpu_data_handle_t vector_handle;
starpu_vector_data_register(&vector_handle, STARPU_MAIN_RAM, (uintptr_t)vector,
NX, sizeof(vector[0]));
float factor = 3.14;
ret = starpu_task_insert(&cl,
/* an argument is passed to the codelet, beware that this is a
* READ-ONLY buffer and that the codelet may be given a pointer to a
* COPY of the argument */
STARPU_VALUE, &factor, sizeof(factor),
/* the codelet manipulates one buffer in RW mode */
STARPU_RW, vector_handle,
0);
STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_insert");
/* Wait for tasks completion */
starpu_task_wait_for_all();
/* StarPU does not need to manipulate the array anymore so we can stop
* monitoring it */
starpu_data_unregister(vector_handle);
#ifdef STARPU_USE_OPENCL
starpu_opencl_unload_opencl(&programs);
#endif
/* terminate StarPU, no task can be submitted after */
starpu_shutdown();
fprintf(stderr, "AFTER First element is %f\n", vector[0]);
return 0;
}
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