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#include <iostream>
#include <stdlib.h>
#include "oneapi/tbb/global_control.h"
#include "oneapi/tbb/parallel_for.h"
#include "oneapi/tbb/blocked_range.h"
using namespace tbb;
using namespace std;
class ArraySummer {
int* p_array_a;
int* p_array_b;
int* p_array_sum;
public:
// This empty constructor with an initialization list is used to setup calls to the function
ArraySummer(int* p_a, int* p_b, int* p_sum) : p_array_a(p_a), p_array_b(p_b), p_array_sum(p_sum) {}
void operator()(const blocked_range<int>& r) const {
for (int i = r.begin(); i != r.end(); i++) { // iterates over the entire chunk
p_array_sum[i] = p_array_a[i] + p_array_b[i];
}
}
};
int main(int argc, char* argv[]) {
int* p_A;
int* p_B;
int* p_SUM_1T;
int* p_SUM_TBB;
/* This is the TBB runtime... */
global_control control(global_control::max_allowed_parallelism, 4);
constexpr int nElements = 10;
p_A = new int[nElements];
p_B = new int[nElements];
p_SUM_1T = new int[nElements];
p_SUM_TBB = new int[nElements];
/*
* Initialize the data sets ... could do this in parallel too, but
* serial is easier to read
*/
p_A[0] = p_B[0] = 0;
p_A[1] = p_B[1] = 1;
for (int i = 2; i < nElements; i++) {
p_A[i] = (p_A[i - 1] + p_A[i - 2]) % (INT_MAX / 2);
p_B[i] = p_A[i];
p_SUM_1T[i] = 0;
p_SUM_TBB[i] = 0;
}
/*
* Time how long it takes to sum the arrays using a single thread
*/
for (int i = 0; i < nElements; i++) {
p_SUM_1T[i] = p_A[i] + p_B[i];
}
/*
* Now sum the arrays again using TBB, again timing the execution
*/
parallel_for(blocked_range<int>(0, nElements, 100), ArraySummer(p_A, p_B, p_SUM_TBB));
/*
* Verify the sums match
*/
for (int i = 0; i < nElements; i++) {
if (p_SUM_1T[i] != p_SUM_TBB[i]) {
cout << p_A[i] << " + " << p_B[i] << " = " << p_SUM_1T[i] << " AND " << p_SUM_TBB[i] << endl;
}
}
delete[] p_A;
delete[] p_B;
delete[] p_SUM_1T;
delete[] p_SUM_TBB;
return 0;
}
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