KernelTimer.H

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/* Copyright 2019-2020 Michael Rowan, Axel Huebl, Kevin Gott
 *
 * This file is part of WarpX.
 *
 * License: BSD-3-Clause-LBNL
 */
#ifndef ABLASTR_KERNELTIMER_H_
#define ABLASTR_KERNELTIMER_H_
 
#include "ablastr/utils/TextMsg.H"
 
#include <AMReX.H>
#include <AMReX_BLassert.H>
#include <AMReX_GpuAtomic.H>
#include <AMReX_GpuQualifiers.H>
#include <AMReX_REAL.H>
 
#include <climits>
 
namespace ablastr::parallelization
{

class KernelTimer
{
public:
    AMREX_GPU_DEVICE
    KernelTimer
    (const bool do_timing, amrex::Real* cost)
#if (defined AMREX_USE_GPU)
        : m_do_timing(do_timing)
#endif
    {
#if (defined AMREX_USE_GPU)
    if (m_do_timing && cost) {
        m_cost = cost;
#   if defined(AMREX_USE_CUDA) || defined(AMREX_USE_HIP)
        // Start the timer
        m_wt = clock64();
 
#   elif defined(AMREX_USE_DPCPP)
        // To be updated
        ABLASTR_ALWAYS_ASSERT_WITH_MESSAGE(m_do_timing == false,
            "KernelTimer not yet supported for this hardware.");
#   endif
    }
#else  // AMREX_USE_GPU
        amrex::ignore_unused(do_timing, cost);
#endif // AMREX_USE_GPU
    }

#if (defined AMREX_USE_GPU)
#   if defined(AMREX_USE_CUDA) || defined(AMREX_USE_HIP)
        AMREX_GPU_DEVICE
        ~KernelTimer ()
        {
            if (m_do_timing && m_cost) {
                m_wt = clock64() - m_wt;
                amrex::Gpu::Atomic::Add( m_cost, amrex::Real(m_wt));
            }
        }
#   elif defined(AMREX_USE_DPCPP)
        // To be updated
        AMREX_GPU_DEVICE
        ~KernelTimer () = default;
#   endif
 
#else
~KernelTimer () = default;
#endif //AMREX_USE_GPU
 
 
    KernelTimer ( KernelTimer const &)             = default;
    KernelTimer& operator= ( KernelTimer const & ) = default;
    KernelTimer ( KernelTimer&& )                  = default;
    KernelTimer& operator= ( KernelTimer&& )       = default;
 
#if (defined AMREX_USE_GPU)
private:
    bool m_do_timing;

    amrex::Real* m_cost = nullptr;

    long long int m_wt;
#endif //AMREX_USE_GPU
};
 
} // namespace ablastr::parallelization
 
#endif // ABLASTR_KERNELTIMER_H_