mutex/example1.cpp

// mutex::lock/unlock
#include <iostream>       // std::cout
#include <thread>         // std::thread
#include <mutex>          // std::mutex
std::mutex mtx;           // mutex for critical section
void print_thread_id (int id) {
    // critical section (exclusive access to std::cout signaled by locking mtx):
    mtx.lock();
    std::cout << "thread #" << id << '\n';
    mtx.unlock();
  }

int main ()
{
    std::thread threads[10];
    // spawn 10 threads:
    for (int i=0; i<10; ++i)
      threads[i] = std::thread(print_thread_id,i+1);
      for (auto& th : threads) th.join();

    return 0;
}