标签: unobserved-exception

我在.NET 4.0中使用TPL(任务并行库).我想通过使用Thread.GetDomain().UnhandledException事件集中处理所有未处理异常的处理逻辑.但是,在我的应用程序中,从未使用TPL代码启动的线程触发事件,例如Task.Factory.StartNew(...).如果我使用类似的东西,事件确实会被解雇new Thread(threadStart).Start().

这篇MSDN文章建议使用Task.Wait()来捕获AggregateException使用TPL的时间,但这不是我想要的,因为这种机制不够"集中".

有没有人遇到过同样的问题,还是仅仅是我？你对此有什么解决方案吗？

我们最近检查了我们的错误日志,看到了很多"操作被取消"的异常.我们无法重现它们,看起来像一个中止的请求,但它们都来自OWIN HostAuthenticationFilter.

这是堆栈跟踪:

System.OperationCanceledException: The operation was canceled.
   at System.Threading.CancellationToken.ThrowOperationCanceledException()
   at System.Web.Http.HostAuthenticationFilter.<AuthenticateAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Http.Tracing.ITraceWriterExtensions.<TraceBeginEndAsyncCore>d__24.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Http.Controllers.AuthenticationFilterResult.<ExecuteAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at …

我有一个继续处理错误的任务:

var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();
var loadTask = Task<List<OrderItemViewModel>>.Factory.StartNew(() =>
{
       throw new Exception("derp");
});

var errorContinue = loadTask.ContinueWith(t =>
    {
        MainViewModel.RemoveViewModel(this);
    }, CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, uiScheduler);

连续命中,但几秒钟后我在应用程序中收到此错误:

通过等待任务或访问其Exception属性,未观察到任务的异常.结果,终结器线程重新抛出了未观察到的异常.

这与uiScheduler有关吗？类似问题的解决方案基本上就是我正在做的事情 .通过等待任务或访问其Exception属性,没有观察到任务的异常.结果,未观察到的例外是

我有一个C#Extension方法,可以与任务一起使用,以确保抛出的任何异常都是在最低限度观察到的,以免崩溃托管进程.在.NET4.5中,行为略有改变,因此不会发生这种情况,但仍会触发未观察到的异常事件.我在这里的挑战是编写一个测试来证明扩展方法是有效的.我正在使用NUnit Test Framework,ReSharper是测试运行者.

我试过了:

var wasUnobservedException = false;
TaskScheduler.UnobservedTaskException += (s, args) => wasUnobservedException = true;
var res = TaskEx.Run(() =>
                          {
                              throw new NaiveTimeoutException();
                              return new DateTime?();
                          });
GC.Collect();
GC.WaitForPendingFinalizers();
Assert.IsTrue(wasUnobservedException);

测试总是失败的Assert.IsTrue.当我手动运行此测试时,在LINQPad之类的东西中,我得到了预期的wasUnobservedException回复行为true.

我猜测测试框架正在捕获异常并观察它,以至于TaskScheduler.UnobservedTaskException永远不会被触发.

我尝试修改代码如下:

var wasUnobservedException = false;
TaskScheduler.UnobservedTaskException += (s, args) => wasUnobservedException = true;
var res = TaskEx.Run(async () =>
                          {
                              await TaskEx.Delay(5000).WithTimeout(1000).Wait();
                              return new DateTime?();
                          });
GC.Collect();
GC.WaitForPendingFinalizers();
Assert.IsTrue(wasUnobservedException);

我在此代码中进行的尝试是在抛出异常之前使任务获得GC'd,以便终结器将看到未捕获的,未观察到的异常.然而,这导致了上述相同的故障.

事实上,是否存在某种由测试框架连接的异常处理程序？如果是这样,有办法吗？或者我只是把事情弄得一团糟,有更好/更容易/更清洁的方法吗？

最近我在我的后端API应用程序中为每个UnobservedTaskException添加了错误记录.原因是某些API调用会执行其他任务,这些任务在我返回结果后完成,这就是为什么我无法跟踪操作(web api调用)级别的错误.

现在我得到了很多"操作被取消"的例外,不知道如何处理它.我甚至不确定这个异常是由我的API调用执行的任务引起的.

这是堆栈:

System.OperationCanceledException: The operation was canceled.
   at System.Threading.CancellationToken.ThrowIfCancellationRequested()
   at System.Web.Http.WebHost.HttpControllerHandler.<WriteBufferedResponseContentAsync>d__1b.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Http.WebHost.HttpControllerHandler.<CopyResponseAsync>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Http.WebHost.HttpControllerHandler.<ProcessRequestAsyncCore>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) …

以下代码在 netcoreapp2.0 应用程序中运行时，似乎最终不会抛出UnobservedTaskException

using System;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp3 {

    class Program {

        public static void Main(string[] args) {

            TaskScheduler.UnobservedTaskException += (s, e) => {
                /// Try to crash the application - we wanna nail unobserved exceptions dead.
                /// Unfortunately, this code never seems to run.
                Console.WriteLine("UnobservedTaskException thrown.");
                throw e.Exception; 
            };

            var t = Task.Run(() => {
                throw new NotImplementedException();
            });

            while (!t.IsFaulted)
                Thread.Sleep(1);

            t = null;
            Console.WriteLine("Task is faulted.");

            GC.Collect();
            GC.WaitForPendingFinalizers();
            Console.ReadKey();
        }

    }
}

这是项目文件。我怎样才能 …