timer.h

#pragma once
#include <chrono>
#include <cuda_runtime.h>
#include "cuda_check.h"

namespace sbfft {

struct CpuTimer {
    std::chrono::steady_clock::time_point t0;
    void tic() { t0 = std::chrono::steady_clock::now(); }
    double toc_ms() const {
        return std::chrono::duration<double, std::milli>(
                   std::chrono::steady_clock::now() - t0).count();
    }
};

struct GpuTimer {
    cudaEvent_t a, b;
    GpuTimer() {
        CUDA_CHECK(cudaEventCreate(&a));
        CUDA_CHECK(cudaEventCreate(&b));
    }
    ~GpuTimer() {
        cudaEventDestroy(a);
        cudaEventDestroy(b);
    }
    GpuTimer(const GpuTimer&) = delete;
    GpuTimer& operator=(const GpuTimer&) = delete;

    void tic(cudaStream_t s = 0) { CUDA_CHECK(cudaEventRecord(a, s)); }
    float toc_ms(cudaStream_t s = 0) {
        CUDA_CHECK(cudaEventRecord(b, s));
        CUDA_CHECK(cudaEventSynchronize(b));
        float ms = 0.f;
        CUDA_CHECK(cudaEventElapsedTime(&ms, a, b));
        return ms;
    }
};

} // namespace sbfft