using System;

using System.Threading.Tasks;

using System.Threading;

public class Program

{

    public static void Main()

    {

        var shared = 0;

        var lck = new object();

        //Write thread

        Task.Run(()=>{

            while(true){

                lock(lck){

                    shared = shared + 1;

                    Monitor.PulseAll(lck);

                }

                Task.Delay(100);

            }

        });

        //Read thread to check value 123

        Task.Run(()=>{

            while(true){

                lock(lck){

                    if(shared == 123){

                        DoSomething(shared);

                        break;

                    }else{

                        Monitor.Wait(lck);

                        if(shared == 123){

                            DoSomething(shared);

                            break;

                        }

                    }

                }

            }

        });

        //Read thread to check value 55

        Task.Run(()=>{

            while(true){

                lock(lck){

                    if(shared == 55){

                        DoSomething(shared);

                        break;

                    }else{

                        Monitor.Wait(lck);

                        if(shared == 55){

                            DoSomething(shared);

                            break;

                        }

                    }

                }

            }

        });

        while(true){

            Thread.Sleep(1000); 

        }

    }

    public static void DoSomething(int value){

        Console.WriteLine("Value reached:" + value.ToString());

    }

}