///////////////////////////////////////////////////////////////
// Atomics.cpp - atomic operations on integral types         //
//                                                           //
// Jim Fawcett, CSE687 - Object Oriented Design, Spring 2013 //
///////////////////////////////////////////////////////////////

#include <atomic>
#include <mutex>
#include <thread>
#include <iostream>

std::mutex mtx;

void up(std::atomic<int>& i)
{
  for(int j=0; j<20; ++j)
  {
    i += 1;
    std::lock_guard<std::mutex> l(mtx);
    std::cout << "\n  t - value of atomic is " << i;
  }
}

int main()
{
  std::atomic<int> i = 0;
  std::thread t(up, std::ref(i));
  for(int j=0; j<8; ++j)
  {
    static bool wait = true;
    if(wait)
      std::this_thread::sleep_for(std::chrono::milliseconds(1));
    wait = false;
    i -= 1;
    std::lock_guard<std::mutex> l(mtx);
    std::cout << "\n  m - value of atomic is " << i;
  }
  t.join();
  std::cout << "\n  value of atomic is " << i;
  std::cout << "\n\n";
}