132 lines
4.2 KiB
C#
132 lines
4.2 KiB
C#
//
|
|
// TaskAwaiter.cs
|
|
//
|
|
// Authors:
|
|
// Marek Safar <marek.safar@gmail.com>
|
|
//
|
|
// Copyright (C) 2011 Novell, Inc (http://www.novell.com)
|
|
// Copyright (C) 2011 Xamarin, Inc (http://www.xamarin.com)
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining
|
|
// a copy of this software and associated documentation files (the
|
|
// "Software"), to deal in the Software without restriction, including
|
|
// without limitation the rights to use, copy, modify, merge, publish,
|
|
// distribute, sublicense, and/or sell copies of the Software, and to
|
|
// permit persons to whom the Software is furnished to do so, subject to
|
|
// the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be
|
|
// included in all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
|
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
//
|
|
|
|
#if NET_4_5
|
|
|
|
using System.Threading;
|
|
using System.Threading.Tasks;
|
|
using System.Runtime.ExceptionServices;
|
|
|
|
namespace System.Runtime.CompilerServices
|
|
{
|
|
public struct TaskAwaiter : ICriticalNotifyCompletion
|
|
{
|
|
readonly Task task;
|
|
|
|
internal TaskAwaiter (Task task)
|
|
{
|
|
this.task = task;
|
|
}
|
|
|
|
public bool IsCompleted {
|
|
get {
|
|
return task.IsCompleted;
|
|
}
|
|
}
|
|
|
|
public void GetResult ()
|
|
{
|
|
if (!task.IsCompleted)
|
|
task.WaitCore (Timeout.Infinite, CancellationToken.None, true);
|
|
|
|
if (task.Status != TaskStatus.RanToCompletion)
|
|
// Merge current and dispatched stack traces if there is any
|
|
ExceptionDispatchInfo.Capture (HandleUnexpectedTaskResult (task)).Throw ();
|
|
}
|
|
|
|
internal static Exception HandleUnexpectedTaskResult (Task task)
|
|
{
|
|
var slot = task.ExceptionSlot;
|
|
switch (task.Status) {
|
|
case TaskStatus.Canceled:
|
|
// Use original exception when we have one
|
|
if (slot.Exception != null)
|
|
goto case TaskStatus.Faulted;
|
|
|
|
return new TaskCanceledException (task);
|
|
case TaskStatus.Faulted:
|
|
// Mark the exception as observed when GetResult throws
|
|
slot.Observed = true;
|
|
return slot.Exception.InnerException;
|
|
default:
|
|
throw new ArgumentException (string.Format ("Unexpected task `{0}' status `{1}'", task.Id, task.Status));
|
|
}
|
|
}
|
|
|
|
internal static void HandleOnCompleted (Task task, Action continuation, bool continueOnSourceContext, bool manageContext)
|
|
{
|
|
if (continueOnSourceContext && SynchronizationContext.Current != null && SynchronizationContext.Current.GetType () != typeof (SynchronizationContext)) {
|
|
task.ContinueWith (new SynchronizationContextContinuation (continuation, SynchronizationContext.Current));
|
|
} else {
|
|
IContinuation cont;
|
|
Task cont_task;
|
|
if (continueOnSourceContext && !TaskScheduler.IsDefault) {
|
|
cont_task = new Task (TaskActionInvoker.Create (continuation), null, CancellationToken.None, TaskCreationOptions.None, null);
|
|
cont_task.SetupScheduler (TaskScheduler.Current);
|
|
cont = new SchedulerAwaitContinuation (cont_task);
|
|
} else {
|
|
cont_task = null;
|
|
cont = new AwaiterActionContinuation (continuation);
|
|
}
|
|
|
|
//
|
|
// This is awaiter continuation. For finished tasks we get false result and need to
|
|
// queue the continuation otherwise the task would block
|
|
//
|
|
if (task.ContinueWith (cont, false))
|
|
return;
|
|
|
|
if (cont_task == null) {
|
|
cont_task = new Task (TaskActionInvoker.Create (continuation), null, CancellationToken.None, TaskCreationOptions.None, null);
|
|
cont_task.SetupScheduler (TaskScheduler.Current);
|
|
}
|
|
|
|
cont_task.Schedule (true);
|
|
}
|
|
}
|
|
|
|
public void OnCompleted (Action continuation)
|
|
{
|
|
if (continuation == null)
|
|
throw new ArgumentNullException ("continuation");
|
|
|
|
HandleOnCompleted (task, continuation, true, true);
|
|
}
|
|
|
|
public void UnsafeOnCompleted (Action continuation)
|
|
{
|
|
if (continuation == null)
|
|
throw new ArgumentNullException ("continuation");
|
|
|
|
HandleOnCompleted (task, continuation, true, false);
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif |