using System.Threading;

using System;

using System.Collections.Concurrent;

public class Program

{

    protected static ConcurrentDictionary<int, object> LockerDictionary = new();

​

public static void Process(int key)

{

    var locker = LockerDictionary.GetOrAdd(key, new object());

​

    lock (locker)

    {

        OperateWithKey(key);

    }

}

​

private static void OperateWithKey(int key)

{

    Console.WriteLine($"Thread {Thread.CurrentThread.ManagedThreadId} is operating on key {key}");

    Thread.Sleep(100); // Simulate some work

    Console.WriteLine($"Thread {Thread.CurrentThread.ManagedThreadId} finished operating on key {key}");

}

    public static void Main()

    {

    // Simulate 5 threads accessing the same key

    int key = 1;

    for (int i = 0; i < 5; i++)

    {

        new Thread(() => Process(key)).Start();

    }

    }

}