Как очистить/очистить объект AsyncLocal<T> в BackgroundService(Microsoft.Hosting.Extensions.BackgroundService)?

У меня есть фоновая служба, которая выполняет некоторые задачи и задания в долго работающем потоке. Для простоты мы будем рассматривать это как планировщик, который выполняет асинхронный вызов SQL и повторяет его. Теперь я использую AsyncLocal для хранения метаданных для целей регистрации в службе и хочу группировать каждое повторение задачи как транзакцию. Я полагал, что в отличие от веб-приложений BackgroundService будет иметь один объект AsyncLocal(ExecutionContext), который мне придется очищать после каждого повторения (каждого вызова SQL в этом примере). Что касается проблемы, я не могу очистить объект.

Вот реализация моего класса хранилища AsyncLocal.

 public class AsyncLocalStorage<T> : ILocalStorage<T>
    {
        private readonly AsyncLocal<T> _context;
        public AsyncLocalStorage()
        {
            _context = new AsyncLocal<T>(OnValueChanged);
        }

        private static void OnValueChanged(AsyncLocalValueChangedArgs<T> args)
        {
            Log("OnValueChanged! Prev: {0} ; Current: {1}", RuntimeHelpers.GetHashCode(args.PreviousValue), RuntimeHelpers.GetHashCode(args.CurrentValue));
        }

        public T GetData()
        {
            try
            {
                return _context.Value;
            }
            catch (Exception ex)
            {
                Log("Ex: " + ex.ToString());
            }

            return default(T);
        }

        public void SetData(T value)
        {
            _context.Value = value;
        }

        public void Clear()
        {
            _context.Value = default(T);
        }
    }

Здесь я присваиваю свои метаданные объекту AsyncLocal, а затем вызываю функцию Clear. Но экземпляр объекта остается. Я приложил журналы для дальнейшего использования.

02-05-2024 20:10:38 - [4:(DEBUG)<t:4>] - [TName: ]TRANSACTION STARTED (The AsyncLocal Object is created and I assign my object "Transaction" using context.SetData()) 
02-05-2024 20:10:38 - [1:(ERROR)<t:4>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:39 - [4:(DEBUG)<t:4>] - [TName: ]The async SQL call is made.... (The Transaction object is modified context.GetData() . I guess the obj is passed to thread 9 )  
02-05-2024 20:10:39 - [1:(ERROR)<t:9>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:39 - [4:(DEBUG)<t:4>] - [TName: ]---- random things are taken care off using the Transaction object that resulted in the following OnValueChanged logs .  
02-05-2024 20:10:39 - [1:(ERROR)<t:5>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:39 - [1:(ERROR)<t:9>] - OnValueChanged! Prev: 5773521 ; Current: 0  
02-05-2024 20:10:39 - [1:(ERROR)<t:5>] - OnValueChanged! Prev: 5773521 ; Current: 0  
02-05-2024 20:10:39 - [1:(ERROR)<t:5>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:39 - [1:(ERROR)<t:5>] - OnValueChanged! Prev: 5773521 ; Current: 0  
02-05-2024 20:10:39 - [4:(DEBUG)<t:4>] - [TName: ]The Async SQL call returned a Task object .  
02-05-2024 20:10:39 - [1:(ERROR)<t:9>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:39 - [4:(DEBUG)<t:4>] - [TName: ]Processing of the metadata done on thread 4 is over.  
02-05-2024 20:10:39 - [1:(ERROR)<t:4>] - OnValueChanged! Prev: 5773521 ; Current: 0  
02-05-2024 20:10:39 - [4:(DEBUG)<t:9>] - [TName: ]Most of the processing on Thread 9 is also over and The Task returned by SQL call has finished. 
02-05-2024 20:10:39 - [4:(DEBUG)<t:9>] - [TName: ]Now the Transaction object is fetched with context.GetData() and is Loaded into a Thread Processor that runs independently using "ThreadPool.QueueWorkItem(Event, transaction) , which happens to be thread 10" 
02-05-2024 20:10:39 - [1:(ERROR)<t:10>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:39 - [4:(DEBUG)<t:9>] - [TName: ]Everything seems to be over and its time to call context.Clear() //called. 
02-05-2024 20:10:39 - [1:(ERROR)<t:9>] - OnValueChanged! Prev: 5773521 ; Current: 0  
02-05-2024 20:10:39 - [4:(DEBUG)<t:9>] - [TName: ]Tried getting the transaction object here to verify using context.GetData(), returned null here.  
02-05-2024 20:10:39 - [4:(DEBUG)<t:10>] - [TName: ProcessThread]Working with the transaction object reference in the Event thread.  
02-05-2024 20:10:39 - [4:(DEBUG)<t:10>] - [TName: ProcessThread]Also working with the transaction object that is passed to this thread processor. Have no idea why the below log has occured.  
02-05-2024 20:10:39 - [1:(ERROR)<t:10>] - OnValueChanged! Prev: 5773521 ; Current: 0  (I am sure the transaction object goes out of scope here)
02-05-2024 20:10:39 - [4:(DEBUG)<t:4>] - [TName: ]TRANSACTION STARTED (new repetition, calling the GetData function again before creating a new transaction object and assigning. I only assign a new object if it is null) 
02-05-2024 20:10:40 - [1:(ERROR)<t:4>] - OnValueChanged! Prev: 0 ; Current: 5773521  
02-05-2024 20:10:40 - [4:(DEBUG)<t:4>] - [TName: ] Suprise suprise!! it is not NULL. I have no idea why it isn't .   
02-05-2024 20:10:40 - [4:(DEBUG)<t:4>] - [TName: ]I have already cleared all the component objects in the transaction object . A New transaction object is needed here. 

Почему это происходит? Есть ли что-то, чего мне не хватает?

Обновлено: Минимальный воспроизводимый пример приведен ниже. Я попытался сделать его маленьким

public class Worker : BackgroundService
 {
     private readonly ILogger<Worker> _logger;
     private readonly BackgroundTask _backgroundtask;

     public Worker(ILogger<Worker> logger, BackgroundTask task)
     {
         _logger = logger;
         _backgroundtask = task;
     }

     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
         while (!stoppingToken.IsCancellationRequested)
         {
             _logger.LogInformation("Worker running at: {time}", DateTimeOffset.Now);
             _backgroundtask.MakeTask();
             await Task.Delay(1000, stoppingToken);
         }
     }
 }

 public sealed class BackgroundTask
 {
     private readonly ILogger<BackgroundTask> _logger;
     
     public BackgroundTask(ILogger<BackgroundTask> logger)
     {
         _logger = logger;
     }

     public void MakeTask()
     {
         Transactions trans = TransactionService.GetCurrentTransaction();

         if (trans == null)
         {
             Console.WriteLine("[T:<{0}>] There is no TransactionObject", Thread.CurrentThread.ManagedThreadId);
             trans = TransactionService.GetOrCreateTransaction();
         }
         else
         {
             Console.WriteLine("[T:<{0}>] There is a Transaction Object", Thread.CurrentThread.ManagedThreadId);
         }

         trans.PrintTransactionName();
  
         Task.Run(() =>
         {
             trans.SetTransactionName("transaction2");
             trans.PrintTransactionName();

             trans.ClearEverything();
         });
     }
 }

 public class TransactionService
 {
     private static AsyncLocalStorage<Transactions> transactionContext;

     static TransactionService()
     {
         transactionContext = new AsyncLocalStorage<Transactions>();
     }

     public static Transactions GetCurrentTransaction()
     {
         return transactionContext.GetData();
     }

     public static Transactions GetOrCreateTransaction()
     {
         var transaction = GetCurrentTransaction();
         if (transaction == null)
         {
             transaction = new Transactions("Transaction1");
             transactionContext.SetData(transaction);
         }
         return transaction;
     }

     public static void RemoveOutstandingTransactions()
     {
         transactionContext.Clear();
     }
 }

 public class Transactions
 {
     private string transactionName;
     public Transactions(string trans)
     {
         transactionName = trans;
     }

     public void SetTransactionName(string trans)
     {
         transactionName = trans;
     }

     public void PrintTransactionName()
     {
         if (!string.IsNullOrEmpty(transactionName))
         {
             Console.WriteLine("[T:<{0}>] The transactionName is {1}", Thread.CurrentThread.ManagedThreadId, transactionName);
         }
     }

     public void ClearEverything()
     {
         transactionName = null;
         Console.WriteLine("[T:<{0}>] The Transaction Object is being cleared", Thread.CurrentThread.ManagedThreadId);
         TransactionService.RemoveOutstandingTransactions();

// Just checking if the object is cleared in this thread.

         if (TransactionService.GetCurrentTransaction() == null)
         {
             Console.WriteLine("[T:<{0}>] The Transaction Object is null after clearing", Thread.CurrentThread.ManagedThreadId);
         }
     }
 }

Создайте Worker-Service с ядром .NET, как показано в приведенном выше примере. Почему объект транзакции появляется в начале следующего повторения после очистки объекта AsyncLocal. Журналы будут выглядеть примерно так...

[T:<1>] There is no TransactionObject
[T:<1>] OnValueChanged! Prev: 0 ; Current: 72766
[T:<1>] The transactionName is Transaction1
[T:<9>] OnValueChanged! Prev: 0 ; Current: 72766
[T:<9>] The transactionName is transaction2
[T:<1>] OnValueChanged! Prev: 72766 ; Current: 0
[T:<9>] The Transaction Object is being cleared
[T:<9>] OnValueChanged! Prev: 72766 ; Current: 0
[T:<9>] The Transaction Object is null after clearing

[T:<6>] There is a Transaction Object
[T:<6>] OnValueChanged! Prev: 72766 ; Current: 0
[T:<9>] OnValueChanged! Prev: 0 ; Current: 72766
[T:<9>] The transactionName is transaction2
[T:<9>] The Transaction Object is being cleared
[T:<9>] OnValueChanged! Prev: 72766 ; Current: 0
[T:<9>] The Transaction Object is null after clearing
[T:<9>] OnValueChanged! Prev: 0 ; Current: 72766

И почему хеш объекта одинаковый?