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#if NET_4_0
//
// TaskCompletionSource.cs
//
// Author:
// Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
//
// Copyright (c) 2009 Jérémie "Garuma" Laval
//
// 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.
using System;
namespace System.Threading.Tasks
{
public class TaskCompletionSource<TResult>
{
Task<TResult> source;
public TaskCompletionSource ()
{
source = new Task<TResult> (null);
}
public TaskCompletionSource (object state)
{
source = new Task<TResult> (null, state);
}
public TaskCompletionSource (TaskCreationOptions options)
{
source = new Task<TResult> (null, options);
}
public TaskCompletionSource (object state, TaskCreationOptions options)
{
source = new Task<TResult> (null, state, options);
}
public void SetCanceled ()
{
if (!ApplyOperation (TaskStatus.Canceled, () => { source.Cancel (); source.CancelReal (); }))
ThrowInvalidException ();
}
public void SetException (Exception e)
{
if (!ApplyOperation (TaskStatus.Faulted, () => source.Exception = e))
ThrowInvalidException ();
}
public void SetResult (TResult result)
{
if (!ApplyOperation (TaskStatus.RanToCompletion, () => source.Result = result))
ThrowInvalidException ();
}
void ThrowInvalidException ()
{
throw new InvalidOperationException ("The underlying Task is already in one of the three final states: RanToCompletion, Faulted, or Canceled.");
}
public bool TrySetCanceled ()
{
return ApplyOperation (TaskStatus.Canceled, () => { source.Cancel (); source.CancelReal (); });
}
public bool TrySetException (Exception e)
{
return ApplyOperation (TaskStatus.Faulted, () => source.Exception = e);
}
public bool TrySetResult (TResult result)
{
return ApplyOperation (TaskStatus.RanToCompletion, () => source.Result = result);
}
bool ApplyOperation (TaskStatus newStatus, Action action)
{
if (CheckInvalidState ())
return false;
if (action != null)
action ();
source.Status = newStatus;
return true;
}
bool CheckInvalidState ()
{
return source.Status == TaskStatus.RanToCompletion ||
source.Status == TaskStatus.Faulted ||
source.Status == TaskStatus.Canceled;
}
public Task<TResult> Task {
get {
return source;
}
}
}
}
#endif
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