Flaky Test: Safe handle has been closed

[mikeharder]

[VSTest] Microsoft.AspNetCore.Server.Kestrel.FunctionalTests.ResponseTests.WhenAppSetsContentLengthToZeroAndDoesNotWriteNoErrorIsThrown(flushResponse: False)
[14:46:24]
[Microsoft.AspNetCore.Server.Kestrel.FunctionalTests.ResponseTests.WhenAppSetsContentLengthToZeroAndDoesNotWriteNoErrorIsThrown(flushResponse: False)] System.AggregateException : One or more errors occurred.
---- System.ObjectDisposedException : Safe handle has been closed
[Microsoft.AspNetCore.Server.Kestrel.FunctionalTests.ResponseTests.WhenAppSetsContentLengthToZeroAndDoesNotWriteNoErrorIsThrown(flushResponse: False)]    at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.FunctionalTests.TestServer.Dispose() in C:\b\w\33bdfc1cae7b2a38\.r\KestrelHttpServer\test\Microsoft.AspNetCore.Server.Kestrel.FunctionalTests\TestServer.cs:line 106
   at Microsoft.AspNetCore.Server.Kestrel.FunctionalTests.ResponseTests.<WhenAppSetsContentLengthToZeroAndDoesNotWriteNoErrorIsThrown>d__25.MoveNext() in C:\b\w\33bdfc1cae7b2a38\.r\KestrelHttpServer\test\Microsoft.AspNetCore.Server.Kestrel.FunctionalTests\ResponseTests.cs:line 828
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
----- Inner Stack Trace -----
   at System.Runtime.InteropServices.SafeHandle.DangerousAddRef(Boolean& success)
   at System.StubHelpers.StubHelpers.SafeHandleAddRef(SafeHandle pHandle, Boolean& success)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking.LibuvFunctions.NativeMethods.uv_async_send(UvAsyncHandle handle)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking.LibuvFunctions.async_send(UvAsyncHandle handle)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.LibuvThread.Post[T](Action`1 callback, T state)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.LibuvThread.<StopAsync>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.LibuvTransport.<StopAsync>d__19.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<StopAsync>d__22.MoveNext()

4/24/17: http://aspnetci/viewLog.html?buildId=207567&tab=buildLog&buildTypeId=Lite_UniverseTest&logTab=tree&filter=err#_

[halter73]

Based on the fact that the ODE is being thrown from LibuvThread.Post() inside LibuvThread.StopAsync(), it appears that the call to Post(t => t.AllowStop()); is throwing. This would mean that uv_run exited before that.

[halter73]

Fixed by #1756

[davidfowl]

@halter73 I did some playing around with the shutdown logic and I don't think this test failure can be an exception on the libuv thread. This test uses the test server which will crash the process if there' s any exception on the libuv thread.

[mikeharder]

@davidfowl: Are you saying you believe this test failure is not actually fixed by #1756?

[davidfowl]

@mikeharder we had some theories yesterday as to why this could possibly happen and I was trying to narrow it down last night. @halter73 's change should this specific issue but we still don't know the root cause.