vector of threads thread pool c 2b 2b

1namespace {
2  std::vector<std::thread> workers;
3
4  int total = 4;
5  int arr[4] = {0};
6
7  void each_thread_does(int i) {
8    arr[i] += 2;
9  }
10}
11
12int main(int argc, char *argv[]) {
13  for (int i = 0; i < 8; ++i) { // for 8 iterations,
14    for (int j = 0; j < 4; ++j) {
15      workers.push_back(std::thread(each_thread_does, j));
16    }
17    for (std::thread &t: workers) {
18      if (t.joinable()) {
19        t.join();
20      }
21    }
22    arr[4] = std::min_element(arr, arr+4);
23  }
24  return 0;
25}
26