我的应用程序需要将插件加载到单独的应用程序域中，然后在其中异步执行一些代码。我已经编写了一些代码来将 Task 包装在可编码类型中:

static class RemoteTask
{
    public static async Task<T> ClientComplete<T>(RemoteTask<T> remoteTask,
                                                  CancellationToken cancellationToken)
    {
        T result;

        using (cancellationToken.Register(remoteTask.Cancel))
        {
            RemoteTaskCompletionSource<T> tcs = new RemoteTaskCompletionSource<T>();
            remoteTask.Complete(tcs);
            result = await tcs.Task;
        }

        await Task.Yield(); // HACK!!

        return result;
    }

    public static RemoteTask<T> ServerStart<T>(Func<CancellationToken, Task<T>> func)
    {
        return new RemoteTask<T>(func);
    }
}

class RemoteTask<T> : MarshalByRefObject
{
    readonly CancellationTokenSource cts = new CancellationTokenSource();
    readonly Task<T> task;

    internal RemoteTask(Func<CancellationToken, Task<T>> starter)
    {
        this.task = starter(cts.Token);
    }

    internal void Complete(RemoteTaskCompletionSource<T> tcs)
    {
        task.ContinueWith(t =>
        {
            if (t.IsFaulted)
            {
                tcs.TrySetException(t.Exception);
            }
            else if (t.IsCanceled)
            {
                tcs.TrySetCancelled();
            }
            else
            {
                tcs.TrySetResult(t.Result);
            }
        }, TaskContinuationOptions.ExecuteSynchronously);
    }

    internal void Cancel()
    {
        cts.Cancel();
    }
}

class RemoteTaskCompletionSource<T> : MarshalByRefObject
{
    readonly TaskCompletionSource<T> tcs = new TaskCompletionSource<T>();

    public bool TrySetResult(T result) { return tcs.TrySetResult(result); }
    public bool TrySetCancelled() { return tcs.TrySetCanceled(); }
    public bool TrySetException(Exception ex) { return tcs.TrySetException(ex); }

    public Task<T> Task
    {
        get
        {
            return tcs.Task;
        }
    }
}

它的用法如下:

sealed class ControllerAppDomain
{
    PluginAppDomain plugin;

    public Task<int> SomethingAsync()
    {
        return RemoteTask.ClientComplete(plugin.SomethingAsync(), CancellationToken.None);
    }
}

sealed class PluginAppDomain : MarshalByRefObject
{
    public RemoteTask<int> SomethingAsync()
    {
        return RemoteTask.ServerStart(async cts =>
        {
            cts.ThrowIfCancellationRequested();
            return 1;
        });
    }
}

但是我遇到了一个障碍。如果您查看 ClientComplete，就会发现我插入了一个 Task.Yield()。如果我注释掉这一行，ClientComplete 将永远不会返回。有什么想法吗？

最佳答案

我最好的猜测是您遇到这些问题是因为包含 await 的async 方法 并且这是通过 ThreadPool 管理的可以分配一些回收线程。

引用资料 Best practice to call ConfigureAwait for all server-side code

Actually, just doing an await can do that(put you on a different thread). Once your async method hits an await, the method is blocked but the thread returns to the thread pool. When the method is ready to continue, any thread is snatched from the thread pool and used to resume the method.

尝试简化代码，为基线案例生成线程并 表现在最后。

关于c# - 结合应用程序域远程处理和任务时出现死锁，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15142507/