消费者生产者问题

#include <iostream>
#include <thread>
#include <mutex>
#include <queue>
#include <chrono>
#include <condition_variable>
using namespace std;
int main(int argc,char **argv){
    queue<int> buffer;
    mutex m;
    condition_variable cond_var;
    int num;

    thread producer([&](){
       while(1){
           this_thread::sleep_for(chrono::seconds(1));

           unique_lock<std::mutex> lock(m);

           num++;
           cout<<"produucing"<<num<<endl;
           buffer.push(num);

           cond_var.notify_one();
       }
    });

    thread consumer([&](){
        while(1){
            unique_lock<mutex> lock(m);

            if(buffer.empty())
                cond_var.wait(lock);

            cout<<"consuming"<<buffer.front()<<endl;
            buffer.pop();
        }
    });
    producer.join();
    consumer.join();
    return 0;
}