starpu-max/doc/tutorial/vector_scal_opencl.c

/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2010, 2011  Université de Bordeaux 1
 * Copyright (C) 2010, 2011, 2012  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>

extern struct starpu_opencl_program programs;

void scal_opencl_func(void *buffers[], void *_args)
{
    float *factor = _args;
    int id, devid, err;
    cl_kernel kernel;
    cl_command_queue queue;
    cl_event event;

    /* length of the vector */
    unsigned n = STARPU_VECTOR_GET_NX(buffers[0]);
    /* OpenCL copy of the vector pointer */
    cl_mem val = (cl_mem) STARPU_VECTOR_GET_DEV_HANDLE(buffers[0]);

    id = starpu_worker_get_id();
    devid = starpu_worker_get_devid(id);

    err = starpu_opencl_load_kernel(&kernel, &queue, &programs,
                    "vector_mult_opencl", devid);   /* Name of the codelet defined above */
    if (err != CL_SUCCESS) STARPU_OPENCL_REPORT_ERROR(err);

    err = clSetKernelArg(kernel, 0, sizeof(val), &val);
    err |= clSetKernelArg(kernel, 1, sizeof(n), &n);
    err |= clSetKernelArg(kernel, 2, sizeof(*factor), factor);
    if (err) STARPU_OPENCL_REPORT_ERROR(err);

    {
        size_t global=1;
        size_t local=1;
        err = clEnqueueNDRangeKernel(queue, kernel, 1, NULL, &global, &local, 0, NULL, &event);
        if (err != CL_SUCCESS) STARPU_OPENCL_REPORT_ERROR(err);
    }

    clFinish(queue);
    starpu_opencl_collect_stats(event);
    clReleaseEvent(event);

    starpu_opencl_release_kernel(kernel);
}