how to use lock in thread?

Question

I have thread1 and thread3 and both of it will edit the std::queue

how to use lock to it?

both of the thread will edit the std::queue in loop.

Answer 1

How you do this depends entirely on what you are doing. One really simple case is the following.

#include <mutex>

static std::mutex s_queue_mutex{};

void thread_proc()
{
	//do other thread stuff
	{
		std::lock_guard<std::mutex> guard_queue(s_queue_mutex);
		//modify queue
		//guard_queue will destruct and unlock the mutex
	}
	//do other thread stuff
}

This creates a global std::mutex that will be used by all threads to protect the queue, and you just use std::lock_guard when you want to protect the queue.