c# - .NET Core 中是否有 CallContext.GetData/SetData 的实现？

Question

AsyncLocal<>在 .NET Core 中，如 CallContext.LogicGetData/LogicSetData .怎么样GetData和 SetData ?
Thread.GetData/SetData , ThreadStatic , ThreadLocal所有这些都有同样的问题，当Thread完成后，这些值将不会清除，如果这些 Thread重用(或者可能是 Thread Id 重用)，LocalValue 已经存在。

class Program
{
    [ThreadStatic]
    private static string Static;
    private static ThreadLocal<string> Local = new ThreadLocal<string>(false);
    private static LocalDataStoreSlot Slot = Thread.AllocateDataSlot();

    static void Main(string[] args)
    {
        var threadIds = new List<int>();
        for (var i = 0; i < 100; i++)
        {
            Task.Run(() =>
            {
                if (threadIds.Contains(Thread.CurrentThread.ManagedThreadId))
                {
                    if(Static == null || Local.Value == null || Thread.GetData(Slot) == null)
                    {
                        // never get in
                    }
                    else
                    {
                        // same thread id always already exists value
                    }
                }
                else
                {
                    threadIds.Add(Thread.CurrentThread.ManagedThreadId);
                    if (Static == null && Local.Value == null && Thread.GetData(Slot) == null)
                    {
                        var threadId = Thread.CurrentThread.ManagedThreadId.ToString();
                        Static = threadId;
                        Local.Value = threadId;
                        Thread.SetData(Slot, threadId);
                    }
                    else
                    {
                        //never get in
                    }
                }
            }).Wait();
        }

        Console.WriteLine("Press any key to continue...");
        Console.ReadKey();
    }
}

我知道怎么做CallContext做，它只是复制LogicalCallContext子线程的值，不要复制 IllogicalCallContext .但只有 .NET Core IAsyncLocalValueMap在ExecutionContext ，它总是复制到子线程(SuppressFlow 除外)。那么，有没有GetData的工具呢？/SetData ？或任何清洁方式ThreadLocal当它完成时。

Answer 1

使用 AsyncLocal 的更改处理程序在线程更改时清除值？

private static AsyncLocal<string> AsyncLocal
    = new AsyncLocal<string>(ThreadContextChanged);

private static void ThreadContextChanged(AsyncLocalValueChangedArgs<string> changedArgs)
{
    if (changedArgs.ThreadContextChanged &&
        changedArgs.CurrentValue != null)
    {
        AsyncLocal.Value = null;
    }
}