main.cpp

#include <iostream>
#include <fstream>
#include <string.h>
#include <unistd.h>

#define L2_cache 3145728 // 3 mb - L2 cache size
#define string_size 16 // 64b - cache string size

using namespace std;

const int N = 3145728;

union ticks {
    unsigned long long t64;
    struct s32 { long th, tl; } t32;
} start, end;

void getT (ostream& F, int* array, int offset){ // function that counts time taken for element

    double minCycles = 0;

    if (array[0] == 0){ // first cache miss
        if (array[string_size * 2] == 0){ // second cache miss

            usleep(100);

            asm("rdtsc\n":"=a"(start.t32.th),"=d"(start.t32.tl));

            if (array[string_size * 4 + offset] == 0){ // acess to the element
                asm("rdtsc\n":"=a"(end.t32.th),"=d"(end.t32.tl));
            }
        }
    }

    minCycles = (end.t64 - start.t64); // counting time

    F << minCycles << endl; // printing time to the file

}

int main(){

    int *array = new int[N];
    int *clearCacheArray = new int[L2_cache];
    int k = 0;

    ofstream F ("measure.log", ofstream::out);

    memset(array, 0, N * sizeof(int));

    memset(clearCacheArray, 0, L2_cache * sizeof(int));

    for (volatile int i = 1; i < 1025; ++i){

        getT(F, array, i);

        for (volatile int j = 0; j < L2_cache; ++j)
            if (clearCacheArray[j] == 0)
                k++;
    }

    cout << "Job done" << endl;

    F.close();

    return 0;
}