Dining Philosophers

#include <iostream>
#include <thread>
#include <mutex>
#include <array>
#include <random>
#include <chrono>
#include <vector>

const int nump=5;
class Philosopher
{
public:
    Philosopher(int n_):n(n_)
    {
        chops.first = n;
        chops.second = (n<4)?n+1:0;
        randgen.seed(n);
    };
    void operator()(std::array<std::mutex,nump>& locks)
    {
        while(true)
        {
            std::chrono::milliseconds sleep_time (randgen()%10000),eat_time(randgen()%10000);
            log("Thinking");
            std::this_thread::sleep_for(sleep_time);

            bool hungry=true;
            int first,second;
            while(hungry)
            {
                int choice =randgen()%2;
                first =chops.first;
                second = chops.second;
                if(choice)
                    std::swap(first,second);

                if(locks[first].try_lock())
                    if(locks[second].try_lock())
                        {
                            log("Eating");
                            std::this_thread::sleep_for(eat_time);
                            hungry=false;
                        }
                    else locks[first].unlock();
                std::this_thread::sleep_for(std::chrono::milliseconds(1));
            }
            locks[first].unlock();
            locks[second].unlock();

        }

    }
    void log(const std::string& data)
    {
        while(!cout_lock.try_lock())std::this_thread::sleep_for(std::chrono::milliseconds(1));
        std::cout<<"Philosopher "<<n<<" "<<data<<std::endl;
        cout_lock.unlock();
    }
private:
    int n;
    std::pair<int,int> chops;
    std::mt19937 randgen;
    static std::mutex cout_lock;
};
std::mutex Philosopher::cout_lock;
int main()
{
    std::array<std::mutex,nump> chops;
    std::vector<std::thread> threads;
    for(int i=0;i<nump;++i)
        threads.push_back
        (
            std::thread
            (
                Philosopher(i),
                std::ref(chops)
            )
        );
    for(auto& t:threads)
        t.join();
    return 0;
}