using System; using System.Threading.Tasks; public class Account { private readonly object balanceLock = new object(); private decimal balance; public Account(decimal initialBalance) { balance = initialBalance; } public decimal Debit(decimal amount) { lock (balanceLock) { if (balance >= amount) { Console.WriteLine($"Balance before debit :{balance, 5}"); Console.WriteLine($"Amount to remove :{amount, 5}"); balance = balance - amount; Console.WriteLine($"Balance after debit :{balance, 5}"); return amount; } else { return 0; } } } public void Credit(decimal amount) { lock (balanceLock) { Console.WriteLine($"Balance before credit:{balance, 5}"); Console.WriteLine($"Amount to add :{amount, 5}"); balance = balance + amount; Console.WriteLine($"Balance after credit :{balance, 5}"); } } } class AccountTest { static void Main() { var account = new Account(1000); var tasks = new Task[100]; for (int i = 0; i < tasks.Length; i++) { tasks[i] = Task.Run(() => RandomlyUpdate(account)); } Task.WaitAll(tasks); } static void RandomlyUpdate(Account account) { var rnd = new Random(); for (int i = 0; i < 10; i++) { var amount = rnd.Next(1, 100); bool doCredit = rnd.NextDouble() < 0.5; if (doCredit) { account.Credit(amount); } else { account.Debit(amount); } } } }