using System;

using System.Threading.Tasks;

​

public class Program

{

     public class Chopstick

    {

        public int numberC;

        public Chopstick(int n)

        {

            this.numberC = n;

        }

    }

​

    public class Person

    {

        public int number;

        public Chopstick left;

        public Chopstick right;

        public Person(Chopstick l, Chopstick r, int n)

        {

            this.left = l;

            this.right = r;

            this.number = n;

        }

​

​

        public void Eat()

        {

            lock (this.left)               

            {

                Console.WriteLine("   person {0} picked {1} chopstick.", this.number, this.left.numberC);

​

                lock (this.right)           

                {

                    Console.WriteLine("   person {0} picked {1} chopstick.", this.number, this.right.numberC);

                    Console.WriteLine("person {0} eats.", this.number);

                    Task.Delay(1000);             

                }

                Console.WriteLine("   person {0} released {1} chopstick.", this.number, this.right.numberC);

            }

            Console.WriteLine("   person {0} released {1} chopstick.", this.number, this.left.numberC);

          }       

    }

    public static void Main()

    {

         {

            const int numPersons = 5;

​

            Chopstick[] chopsticks = new Chopstick[numPersons];

​

            for (int i = 0; i < numPersons; i++)

            {

                chopsticks[i] = new Chopstick(i + 1);

            }

            Task[] tasks = new Task[numPersons];

​

            for (int i = 0; i < numPersons; i++)

            {

                int personNum = i + 1;

                Person person = new Person(chopsticks[i], chopsticks[personNum % numPersons], personNum);

                tasks[i] = new Task(() =>

                                            person.Eat());

            }

            Parallel.ForEach(tasks, t =>

            {

                t.Start();

            });

​

            Task.WaitAll(tasks);

            Console.WriteLine("\n Done - all 5 people have eaten.");

            Console.ReadLine();

        }

    }

}