#region
/* -----------------------------------------------------------------------
*
*
* Copyright 2011-2012 GRNET S.A. All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
*
* THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and
* documentation are those of the authors and should not be
* interpreted as representing official policies, either expressed
* or implied, of GRNET S.A.
*
* -----------------------------------------------------------------------
*/
#endregion
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace Pithos.Core
{
public static class TaskExtensions
{
public static Task Then(this Task first, Func> next)
{
if (first == null)
throw new ArgumentNullException("first");
if (next == null)
throw new ArgumentNullException("next");
Contract.EndContractBlock();
return Then(first, next, CancellationToken.None);
}
public static Task Then(this Task first, Func next)
{
if (first == null)
throw new ArgumentNullException("first");
if (next == null)
throw new ArgumentNullException("next");
Contract.EndContractBlock();
return Then(first, next, CancellationToken.None);
}
public static Task Then(this Task first, Func> next, CancellationToken cancellationToken)
{
if (first == null)
throw new ArgumentNullException("first");
if (next == null)
throw new ArgumentNullException("next");
Contract.EndContractBlock();
Contract.Assume(TaskScheduler.Current!=null);
var tcs = new TaskCompletionSource();
first.ContinueWith(delegate
{
if (first.IsFaulted) tcs.TrySetException(first.Exception.InnerExceptions);
else if (first.IsCanceled) tcs.TrySetCanceled();
else
{
try
{
var t = next(first.Result);
if (t == null) tcs.TrySetCanceled();
else t.ContinueWith(delegate
{
if (t.IsFaulted) tcs.TrySetException(t.Exception.InnerExceptions);
else if (t.IsCanceled) tcs.TrySetCanceled();
else tcs.TrySetResult(t.Result);
}, TaskContinuationOptions.ExecuteSynchronously);
}
catch (Exception exc) { tcs.TrySetException(exc); }
}
}, cancellationToken, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Current);
return tcs.Task;
}
public static Task Then(this Task first, Func next, CancellationToken cancellationToken)
{
if (first == null)
throw new ArgumentNullException("first");
if (next == null)
throw new ArgumentNullException("next");
Contract.EndContractBlock();
Contract.Assume(TaskScheduler.Current != null);
var tcs = new TaskCompletionSource