// Disable the "reference to volatile field not treated as volatile" error.
#pragma warning disable 0420
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Runtime.ExceptionServices;
+
namespace System.Threading.Tasks
{
- using System;
- using System.Collections.Generic;
- using System.Collections.ObjectModel;
- using System.Diagnostics;
- using System.Runtime.ExceptionServices;
- using System.Security;
-
/// <summary>
/// An exception holder manages a list of exceptions for one particular task.
/// It offers the ability to aggregate, but more importantly, also offers intrinsic
/// support for propagating unhandled exceptions that are never observed. It does
- /// this by aggregating and throwing if the holder is ever GC'd without the holder's
- /// contents ever having been requested (e.g. by a Task.Wait, Task.get_Exception, etc).
- /// This behavior is prominent in .NET 4 but is suppressed by default beyond that release.
+ /// this by aggregating and calling UnobservedTaskException event event if the holder
+ /// is ever GC'd without the holder's contents ever having been requested
+ /// (e.g. by a Task.Wait, Task.get_Exception, etc).
/// </summary>
internal class TaskExceptionHolder
{
- /// <summary>Whether we should propagate exceptions on the finalizer.</summary>
- private readonly static bool s_failFastOnUnobservedException = ShouldFailFastOnUnobservedException();
- /// <summary>Whether the AppDomain has started to unload.</summary>
- private static volatile bool s_domainUnloadStarted;
- /// <summary>An event handler used to notify of domain unload.</summary>
- private static volatile EventHandler s_adUnloadEventHandler;
-
/// <summary>The task with which this holder is associated.</summary>
private readonly Task m_task;
/// <summary>
{
Debug.Assert(task != null, "Expected a non-null task.");
m_task = task;
- EnsureADUnloadCallbackRegistered();
- }
-
- private static bool ShouldFailFastOnUnobservedException()
- {
- return false;
- }
-
- private static void EnsureADUnloadCallbackRegistered()
- {
- if (s_adUnloadEventHandler == null &&
- Interlocked.CompareExchange(ref s_adUnloadEventHandler,
- AppDomainUnloadCallback,
- null) == null)
- {
- AppDomain.CurrentDomain.DomainUnload += s_adUnloadEventHandler;
- }
- }
-
- private static void AppDomainUnloadCallback(object sender, EventArgs e)
- {
- s_domainUnloadStarted = true;
}
/// <summary>
// We need to do this filtering because all TaskExceptionHolders will be finalized during shutdown or unload
// regardles of reachability of the task (i.e. even if the user code was about to observe the task's exception),
// which can otherwise lead to spurious crashes during shutdown.
- if (m_faultExceptions != null && !m_isHandled &&
- !Environment.HasShutdownStarted && !AppDomain.CurrentDomain.IsFinalizingForUnload() && !s_domainUnloadStarted)
+ if (m_faultExceptions != null && !m_isHandled && !Environment.HasShutdownStarted)
{
// We don't want to crash the finalizer thread if any ThreadAbortExceptions
// occur in the list or in any nested AggregateExceptions.
// other finalizer, and the Task was finalized before the holder, the holder
// will have been marked as handled before even getting here.
- // Give users a chance to keep this exception from crashing the process
-
- // First, publish the unobserved exception and allow users to observe it
+ // Publish the unobserved exception and allow users to observe it
AggregateException exceptionToThrow = new AggregateException(
SR.TaskExceptionHolder_UnhandledException,
m_faultExceptions);
UnobservedTaskExceptionEventArgs ueea = new UnobservedTaskExceptionEventArgs(exceptionToThrow);
TaskScheduler.PublishUnobservedTaskException(m_task, ueea);
-
- // Now, if we are still unobserved and we're configured to crash on unobserved, throw the exception.
- // We need to publish the event above even if we're not going to crash, hence
- // why this check doesn't come at the beginning of the method.
- if (s_failFastOnUnobservedException && !ueea.m_observed)
- {
- throw exceptionToThrow;
- }
}
}
projects / platform / upstream / dotnet / runtime.git / commitdiff