/*
 * Copyright (c) 2016-2018 ARM Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "arm_compute/runtime/CL/CLScheduler.h"

#include "arm_compute/core/CL/ICLKernel.h"
#include "arm_compute/runtime/CL/CLTuner.h"
#include "arm_compute/runtime/CL/tuners/Tuners.h"

using namespace arm_compute;

namespace
{
#if defined(ARM_COMPUTE_DEBUG_ENABLED)
void printf_callback(const char *buffer, unsigned int len, size_t complete, void *user_data)
{
    printf("%.*s", len, buffer);
}
#endif /* defined(ARM_COMPUTE_DEBUG_ENABLED) */
} // namespace

std::once_flag CLScheduler::_initialize_symbols;

CLScheduler::CLScheduler()
    : _context(), _queue(), _target(GPUTarget::MIDGARD), _is_initialised(false), _cl_tuner(nullptr), _cl_default_static_tuner(nullptr)
{
}

CLScheduler &CLScheduler::get()
{
    std::call_once(_initialize_symbols, opencl_is_available);
    static CLScheduler scheduler;
    return scheduler;
}

void CLScheduler::default_init(ICLTuner *cl_tuner)
{
    if(!_is_initialised)
    {
        std::vector<cl::Platform> platforms;
        cl::Platform::get(&platforms);
        ARM_COMPUTE_ERROR_ON_MSG(platforms.size() == 0, "Couldn't find any OpenCL platform");
        cl::Platform            p = platforms[0];
        cl::Context             ctx;
        cl::Device              device;
        std::vector<cl::Device> platform_devices;
        p.getDevices(CL_DEVICE_TYPE_DEFAULT, &platform_devices);
        ARM_COMPUTE_ERROR_ON_MSG(platform_devices.size() == 0, "Couldn't find any OpenCL device");
        device = platform_devices[0];
#if defined(ARM_COMPUTE_DEBUG_ENABLED)

        // Query devices in the context for cl_arm_printf support
        if(device_supports_extension(device, "cl_arm_printf"))
        {
            // Create a cl_context with a printf_callback and user specified buffer size.
            cl_context_properties properties[] =
            {
                CL_CONTEXT_PLATFORM, reinterpret_cast<cl_context_properties>(p()),
                // Enable a printf callback function for this context.
                CL_PRINTF_CALLBACK_ARM, reinterpret_cast<cl_context_properties>(printf_callback),
                // Request a minimum printf buffer size of 4MB for devices in the
                // context that support this extension.
                CL_PRINTF_BUFFERSIZE_ARM, 0x1000,
                0
            };
            ctx = cl::Context(device, properties);
        }
        else
#endif // defined(ARM_COMPUTE_DEBUG_ENABLED)
        {
            cl_context_properties properties[] =
            {
                CL_CONTEXT_PLATFORM, reinterpret_cast<cl_context_properties>(p()),
                0
            };
            ctx = cl::Context(device, properties);
        };

        cl::CommandQueue queue = cl::CommandQueue(ctx, device);
        CLKernelLibrary::get().init("./cl_kernels/", ctx, device);
        init(ctx, queue, device, cl_tuner);

        // Create a default static tuner and set if none was provided
        _cl_default_static_tuner = tuners::TunerFactory::create_tuner(_target);
    }

    // Set CL tuner
    _cl_tuner = (cl_tuner == nullptr) ? _cl_default_static_tuner.get() : cl_tuner;
}

void CLScheduler::enqueue(ICLKernel &kernel, bool flush)
{
    ARM_COMPUTE_ERROR_ON_MSG(!_is_initialised,
                             "The CLScheduler is not initialised yet! Please call the CLScheduler::get().default_init(), \
                             or CLScheduler::get()::init() and CLKernelLibrary::get()::init() function before running functions!");

    // Tune the kernel if the CLTuner has been provided
    if(_cl_tuner != nullptr)
    {
        // Tune the OpenCL kernel
        _cl_tuner->tune_kernel_dynamic(kernel);
    }

    // Run kernel
    kernel.run(kernel.window(), _queue);

    if(flush)
    {
        _queue.flush();
    }
}