C++11 多线程-std::condition_variable

#include <iostream>
#include <thread>
#include <condition_variable>
#include <queue>
std::mutex mtx;
std::condition_variable cv;
int signal_sym = 0;

struct MySturuct
{
	int a;
};
std::queue<MySturuct>;

void PrintString_1()
{
	std::unique_lock<std::mutex> lk(mtx);
	int cnt = 0;
	while (cnt < 10)
	{
		while (signal_sym != 0)
			cv.wait(lk);
		std::cout << std::this_thread::get_id() << " : " << "A" << std::endl;
		signal_sym = 1;
		cnt++;
		cv.notify_one();
	}
}

void PrintString_2()
{
	std::unique_lock<std::mutex> lk(mtx);
	int cnt = 0;
	while (cnt < 10)
	{
		while (signal_sym != 1)
			cv.wait(lk);
		std::cout << std::this_thread::get_id() << " : " << "B" << std::endl;
		signal_sym = 2;
		cnt++;
		cv.notify_one();
	}
}

void PrintString_3()
{
	std::unique_lock<std::mutex> lk(mtx);
	int cnt = 0;
	while (cnt < 10)
	{
		while (signal_sym != 2)
			cv.wait(lk);
		std::cout << std::this_thread::get_id() << " : " << "C" << std::endl;
		signal_sym = 0;
		cnt++;
		cv.notify_one();
	}
}


int main()
{
	std::thread  t1(PrintString_1);
	std::thread  t2(PrintString_2);
	std::thread  t3(PrintString_3);
	t1.join();
	t2.join();
	t3.join();
	return 0;
}

可以参考std::condition_variable notify_one()与notify_all()的区别_xupeng1644的博客-优快云博客，学习一下notify_one和notify_all；