// conditionVariablePingPong.cpp
#include <condition_variable>
#include <iostream>
#include <thread>
#include <atomic>
bool dataReady= false;
std::mutex mutex_;
std::condition_variable condVar1;
std::condition_variable condVar2;
std::atomic<int> counter{};
int COUNTLIMIT=50;
void setTrue(){
  while(counter <= COUNTLIMIT){
    std::unique_lock<std::mutex> lck(mutex_);
    condVar1.wait(lck, []{return dataReady == false;});
    dataReady= true;
    ++counter;
    std::cout << dataReady << std::endl;
    condVar2.notify_one();
  }
}
void setFalse(){
  while(counter < COUNTLIMIT){
    std::unique_lock<std::mutex> lck(mutex_);
    condVar2.wait(lck, []{return dataReady == true;});
    dataReady= false;
    std::cout << dataReady << std::endl;
    condVar1.notify_one();
  }
}
int main(){
  std::cout << std::boolalpha << std::endl;
  std::cout << "Begin: " << dataReady << std::endl;
  std::thread t1(setTrue);
  std::thread t2(setFalse);
  t1.join();
  t2.join();
  
  dataReady= false;
  std::cout << "End: " << dataReady << std::endl;
  std::cout << std::endl;
}