C++11新特性线程及锁的使用

可能通过mutex或用lock_guard加锁，保证 counter++的原子性操作。

#include <iostream>
#include <thread>
#include <vector>
#include <mutex>
#include <chrono>
#include <stdexcept>

using namespace std;
int counter = 0;
std::mutex mtx;

void increase(int time) {
    for (int i = 0; i < time; i++) {
        //mtx.lock();
        //std::lock_guard<std::mutex> lk(mtx);
        // 当前线程休眠1毫秒
        std::this_thread::sleep_for(std::chrono::milliseconds(1));
        counter++;
        //mtx.unlock();
    }
}

int main(int argc, char** argv) {
    std::thread th1(increase, 100);
    std::thread th2(increase, 100);
    cout << "mytest:" << endl;
    th1.join();
    th2.join();
    std::cout << "counter:" << counter << std::endl;
    return 0;
}