/*************************************************************************
 * Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
 * Modifications Copyright (c) 2020-2022 Advanced Micro Devices, Inc. All rights reserved.
 *
 * See LICENSE.txt for license information
 ************************************************************************/

#include "timer.h"

// Make sure to compile this translation unit with the host compiler and not
// nvcc, lest you hit an internal compiler error (ICE) with GCC 10.3.0
#include <chrono>

namespace
{
std::uint64_t
now()
{
    using clock = std::chrono::steady_clock;
    return std::chrono::duration_cast<std::chrono::nanoseconds>(
               clock::now().time_since_epoch())
        .count();
}
}  // namespace

timer::timer() { t0 = now(); }

double
timer::elapsed() const
{
    std::uint64_t t1 = now();
    return 1.e-9 * (t1 - t0);
}

double
timer::reset()
{
    std::uint64_t t1  = now();
    double        ans = 1.e-9 * (t1 - t0);
    t0                = t1;
    return ans;
}