TaskFactory.cs

Go to the documentation of this file.

// 
// TaskFactory.cs
//  
// Authors:
//       Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
//       Marek Safar <marek.safar@gmail.com>
// 
// Copyright (c) 2009 Jérémie "Garuma" Laval
// Copyright 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_0

namespace System.Threading.Tasks
{
    public class TaskFactory
    {
        readonly TaskScheduler scheduler;
        TaskCreationOptions creationOptions;
        TaskContinuationOptions continuationOptions;
        CancellationToken cancellationToken;
        
        public TaskFactory ()
            : this (CancellationToken.None, TaskCreationOptions.None, TaskContinuationOptions.None, null)
        {
        }

        public TaskFactory (CancellationToken cancellationToken)
            : this (cancellationToken, TaskCreationOptions.None, TaskContinuationOptions.None, null)
        {   
        }

        public TaskFactory (TaskScheduler scheduler)
            : this (CancellationToken.None, TaskCreationOptions.None, TaskContinuationOptions.None, scheduler)
        {   
        }
        
        public TaskFactory (TaskCreationOptions creationOptions, TaskContinuationOptions continuationOptions)
            : this (CancellationToken.None, creationOptions, continuationOptions, null)
        {   
        }
        
        public TaskFactory (CancellationToken cancellationToken, TaskCreationOptions creationOptions, TaskContinuationOptions continuationOptions,
                            TaskScheduler scheduler)
        {
            this.cancellationToken = cancellationToken;
            this.scheduler = scheduler;
            this.creationOptions = creationOptions;
            this.continuationOptions = continuationOptions;

            CheckContinuationOptions (continuationOptions);
        }
        
        public TaskScheduler Scheduler {
            get {
                return scheduler;
            }
        }
        
        public TaskContinuationOptions ContinuationOptions {
            get {
                return continuationOptions;
            }
        }
        
        public TaskCreationOptions CreationOptions {
            get {
                return creationOptions;
            }
        }
        
        public CancellationToken CancellationToken {
            get {
                return cancellationToken;
            }
        }

        internal static void CheckContinuationOptions (TaskContinuationOptions continuationOptions)
        {
            if ((continuationOptions & (TaskContinuationOptions.OnlyOnRanToCompletion | TaskContinuationOptions.NotOnRanToCompletion)) != 0)
                throw new ArgumentOutOfRangeException ("continuationOptions");

            const TaskContinuationOptions long_running = TaskContinuationOptions.LongRunning | TaskContinuationOptions.ExecuteSynchronously;
            if ((continuationOptions & long_running) == long_running)
                throw new ArgumentOutOfRangeException ("continuationOptions", "Synchronous continuations cannot be long running");
        }
        
        #region StartNew for Task
        public Task StartNew (Action action)
        {
            return StartNew (action, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task StartNew (Action action, CancellationToken cancellationToken)
        {
            return StartNew (action, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task StartNew (Action action, TaskCreationOptions creationOptions)
        {
            return StartNew (action, cancellationToken, creationOptions, GetScheduler ());
        }

        public Task StartNew (Action action, CancellationToken cancellationToken, TaskCreationOptions creationOptions, TaskScheduler scheduler)
        {
            Task t = new Task (action, cancellationToken, creationOptions);

            //
            // Don't start cancelled task it would throw an exception
            //
            if (!t.IsCompleted)
                t.Start (scheduler);

            return t;
        }
        
        public Task StartNew (Action<object> action, object state)
        {
            return StartNew (action, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task StartNew (Action<object> action, object state, CancellationToken cancellationToken)
        {
            return StartNew (action, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task StartNew (Action<object> action, object state, TaskCreationOptions creationOptions)
        {
            return StartNew (action, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task StartNew (Action<object> action, object state, CancellationToken cancellationToken, TaskCreationOptions creationOptions,
                              TaskScheduler scheduler)
        {
            Task t = new Task (action, state, cancellationToken, creationOptions);

            //
            // Don't start cancelled task it would throw an exception
            //
            if (!t.IsCompleted)
                t.Start (scheduler);
            
            return t;
        }
        #endregion
        
        #region StartNew for Task<TResult>  
        public Task<TResult> StartNew<TResult> (Func<TResult> function)
        {
            return StartNew<TResult> (function, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew<TResult> (Func<TResult> function, TaskCreationOptions creationOptions)
        {
            return StartNew<TResult> (function, cancellationToken, creationOptions, GetScheduler ());

        }
        
        public Task<TResult> StartNew<TResult> (Func<TResult> function, CancellationToken cancellationToken)
        {
            return StartNew<TResult> (function, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew<TResult> (Func<TResult> function,
                                                CancellationToken cancellationToken,
                                                TaskCreationOptions creationOptions,
                                                TaskScheduler scheduler)
        {
            var t = new Task<TResult> (function, cancellationToken, creationOptions);

            //
            // Don't start cancelled task it would throw an exception
            //
            if (!t.IsCompleted)
                t.Start (scheduler);

            return t;
        }
        
        public Task<TResult> StartNew<TResult> (Func<object, TResult> function, object state)
        {
            return StartNew<TResult> (function, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew<TResult> (Func<object, TResult> function, object state, CancellationToken cancellationToken)
        {
            return StartNew<TResult> (function, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew<TResult> (Func<object, TResult> function, object state, TaskCreationOptions creationOptions)
        {
            return StartNew<TResult> (function, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew<TResult> (Func<object, TResult> function, object state,
                                                CancellationToken cancellationToken,
                                                TaskCreationOptions creationOptions,
                                                TaskScheduler scheduler)
        {
            Task<TResult> t = new Task<TResult> (function, state, cancellationToken, creationOptions);
            t.Start (scheduler);
            
            return t;
        }
        #endregion
        
        #region Continue
        
        public Task ContinueWhenAny (Task[] tasks, Action<Task> continuationAction)
        {
            return ContinueWhenAny (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAny (Task[] tasks, Action<Task> continuationAction, CancellationToken cancellationToken)
        {
            return ContinueWhenAny (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAny (Task[] tasks, Action<Task> continuationAction, TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAny (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task ContinueWhenAny (Task[] tasks, Action<Task> continuationAction, CancellationToken cancellationToken, TaskContinuationOptions continuationOptions, TaskScheduler scheduler)
        {
            CheckContinueArguments (tasks, continuationAction, continuationOptions, scheduler);

            var cont = Task.WhenAnyCore (tasks).ContinueWith (TaskActionInvoker.CreateSelected (continuationAction), cancellationToken, continuationOptions, scheduler);

            return cont;
        }
        
        public Task ContinueWhenAny<TAntecedentResult> (Task<TAntecedentResult>[] tasks,
                                                        Action<Task<TAntecedentResult>> continuationAction)
        {
            return ContinueWhenAny (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAny<TAntecedentResult> (Task<TAntecedentResult>[] tasks,
                                                        Action<Task<TAntecedentResult>> continuationAction,
                                                        CancellationToken cancellationToken)
        {
            return ContinueWhenAny (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAny<TAntecedentResult> (Task<TAntecedentResult>[] tasks,
                                                        Action<Task<TAntecedentResult>> continuationAction,
                                                        TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAny (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task ContinueWhenAny<TAntecedentResult> (Task<TAntecedentResult>[] tasks,
                                                        Action<Task<TAntecedentResult>> continuationAction,
                                                        CancellationToken cancellationToken,
                                                        TaskContinuationOptions continuationOptions,
                                                        TaskScheduler scheduler)
        {
            return ContinueWhenAny ((Task[]) tasks,
                                    (o) => continuationAction ((Task<TAntecedentResult>)o),
                                    cancellationToken, continuationOptions, scheduler);
        }

        public Task<TResult> ContinueWhenAny<TResult> (Task[] tasks, Func<Task, TResult> continuationFunction)
        {
            return ContinueWhenAny (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task<TResult> ContinueWhenAny<TResult> (Task[] tasks,
                                                       Func<Task, TResult> continuationFunction,
                                                       CancellationToken cancellationToken)
        {
            return ContinueWhenAny (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task<TResult> ContinueWhenAny<TResult> (Task[] tasks,
                                                       Func<Task, TResult> continuationFunction,
                                                       TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAny (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task<TResult> ContinueWhenAny<TResult> (Task[] tasks,
                                                       Func<Task, TResult> continuationFunction,
                                                       CancellationToken cancellationToken,
                                                       TaskContinuationOptions continuationOptions,
                                                       TaskScheduler scheduler)
        {
            CheckContinueArguments (tasks, continuationFunction, continuationOptions, scheduler);

            var cont = Task.WhenAnyCore (tasks).ContinueWith<TResult> (TaskActionInvoker.Create (continuationFunction, tasks), cancellationToken, continuationOptions, scheduler);

            return cont;
        }

        public Task<TResult> ContinueWhenAny<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks,
                                                                          Func<Task<TAntecedentResult>, TResult> continuationFunction)
        {
            return ContinueWhenAny (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task<TResult> ContinueWhenAny<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks,
                                                                          Func<Task<TAntecedentResult>, TResult> continuationFunction,
                                                                          CancellationToken cancellationToken)
        {
            return ContinueWhenAny (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task<TResult> ContinueWhenAny<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks,
                                                                          Func<Task<TAntecedentResult>, TResult> continuationFunction,
                                                                          TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAny (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }

        public Task<TResult> ContinueWhenAny<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks,
                                                                          Func<Task<TAntecedentResult>, TResult> continuationFunction,
                                                                          CancellationToken cancellationToken,
                                                                          TaskContinuationOptions continuationOptions,
                                                                          TaskScheduler scheduler)
        {
            return ContinueWhenAny<TResult> ((Task[])tasks,
                                             (t) => continuationFunction((Task<TAntecedentResult>)t),
                                             cancellationToken,
                                             continuationOptions,
                                             scheduler);
        }
        
        public Task ContinueWhenAll (Task[] tasks, Action<Task[]> continuationAction)
        {
            return ContinueWhenAll (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAll (Task[] tasks, Action<Task[]> continuationAction, CancellationToken cancellationToken)
        {
            return ContinueWhenAll (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAll (Task[] tasks, Action<Task[]> continuationAction,
                                     TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAll (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAll (Task[] tasks, Action<Task[]> continuationAction, CancellationToken cancellationToken,
                                     TaskContinuationOptions continuationOptions, TaskScheduler scheduler)
        {
            CheckContinueArguments (tasks, continuationAction, continuationOptions, scheduler);

            var cont = Task.WhenAllCore (tasks).ContinueWith (TaskActionInvoker.Create (continuationAction, tasks), cancellationToken, continuationOptions, scheduler);

            return cont;
        }
        
        public Task ContinueWhenAll<TAntecedentResult> (Task<TAntecedentResult>[] tasks,
                                                        Action<Task<TAntecedentResult>[]> continuationAction)
        {
            return ContinueWhenAll (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAll<TAntecedentResult> (Task<TAntecedentResult>[] tasks,
                                                        Action<Task<TAntecedentResult>[]> continuationAction, CancellationToken cancellationToken)
        {
            return ContinueWhenAll (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAll<TAntecedentResult> (Task<TAntecedentResult>[] tasks, Action<Task<TAntecedentResult>[]> continuationAction,
                                                        TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAll (tasks, continuationAction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task ContinueWhenAll<TAntecedentResult> (Task<TAntecedentResult>[] tasks, 
                                                        Action<Task<TAntecedentResult>[]> continuationAction,
                                                        CancellationToken cancellationToken, TaskContinuationOptions continuationOptions,
                                                        TaskScheduler scheduler)
        {
            return ContinueWhenAll ((Task[]) tasks, (o) => continuationAction (tasks), cancellationToken,
                                    continuationOptions, scheduler);
        }
        
        public Task<TResult> ContinueWhenAll<TResult> (Task[] tasks, Func<Task[], TResult> continuationFunction)
        {
            return ContinueWhenAll<TResult> (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task<TResult> ContinueWhenAll<TResult> (Task[] tasks, Func<Task[], TResult> continuationFunction,
                                                       TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAll<TResult> (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task<TResult> ContinueWhenAll<TResult> (Task[] tasks, Func<Task[], TResult> continuationFunction,
                                                       CancellationToken cancellationToken)
        {
            return ContinueWhenAll<TResult> (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task<TResult> ContinueWhenAll<TResult> (Task[] tasks, Func<Task[], TResult> continuationFunction,
                                                       CancellationToken cancellationToken,
                                                       TaskContinuationOptions continuationOptions, TaskScheduler scheduler)
        {
            CheckContinueArguments (tasks, continuationFunction, continuationOptions, scheduler);

            var cont = Task.WhenAllCore (tasks).ContinueWith<TResult> (TaskActionInvoker.Create (continuationFunction, tasks), cancellationToken, continuationOptions, scheduler);

            return cont;
        }
        
        public Task<TResult> ContinueWhenAll<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks,
                                                                          Func<Task<TAntecedentResult>[], TResult> continuationFunction)
        {
            return ContinueWhenAll<TAntecedentResult, TResult> (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task<TResult> ContinueWhenAll<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks, 
                                                                          Func<Task<TAntecedentResult>[], TResult> continuationFunction,
                                                                          TaskContinuationOptions continuationOptions)
        {
            return ContinueWhenAll<TAntecedentResult, TResult> (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task<TResult> ContinueWhenAll<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks,
                                                                          Func<Task<TAntecedentResult>[], TResult> continuationFunction,
                                                                          CancellationToken cancellationToken)
        {
            return ContinueWhenAll<TAntecedentResult, TResult> (tasks, continuationFunction, cancellationToken, continuationOptions, GetScheduler ());
        }
        
        public Task<TResult> ContinueWhenAll<TAntecedentResult, TResult> (Task<TAntecedentResult>[] tasks, 
                                                                          Func<Task<TAntecedentResult>[], TResult> continuationFunction,
                                                                          CancellationToken cancellationToken,
                                                                          TaskContinuationOptions continuationOptions,
                                                                          TaskScheduler scheduler)
        {
            return ContinueWhenAll<TResult> ((Task[]) tasks,
                                             (o) => continuationFunction (tasks),
                                             cancellationToken,
                                             continuationOptions, scheduler);
        }

        #endregion

        #region FromAsync IAsyncResult
        
        public Task FromAsync (IAsyncResult asyncResult, Action<IAsyncResult> endMethod)
        {
            return FromAsync (asyncResult, endMethod, creationOptions);
        }
        
        public Task FromAsync (IAsyncResult asyncResult, Action<IAsyncResult> endMethod, TaskCreationOptions creationOptions)
        {
            return FromAsync (asyncResult, endMethod, creationOptions, GetScheduler ());
        }

        public Task FromAsync (IAsyncResult asyncResult, Action<IAsyncResult> endMethod, TaskCreationOptions creationOptions, TaskScheduler scheduler)
        {
            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            return TaskFactory<object>.FromIAsyncResult (asyncResult,
                l => {
                    endMethod (asyncResult);
                    return null;
                }, creationOptions, scheduler);
        }
        
        public Task<TResult> FromAsync<TResult> (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod)
        {
            return FromAsync<TResult> (asyncResult, endMethod, creationOptions);
        }
        
        public Task<TResult> FromAsync<TResult> (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod, TaskCreationOptions creationOptions)
        {
            return FromAsync<TResult> (asyncResult, endMethod, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> FromAsync<TResult> (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod, TaskCreationOptions creationOptions, TaskScheduler scheduler)
        {
            return TaskFactory<TResult>.FromIAsyncResult (asyncResult, endMethod, creationOptions, scheduler);
        }

        #endregion

        #region FromAsync Begin/End Method

        public Task FromAsync (Func<AsyncCallback, object, IAsyncResult> beginMethod, Action<IAsyncResult> endMethod, object state)
        {
            return FromAsync (beginMethod, endMethod, state, creationOptions);
        }

        public Task FromAsync (Func<AsyncCallback, object, IAsyncResult> beginMethod, Action<IAsyncResult> endMethod,
                               object state, TaskCreationOptions creationOptions)
        {
            return TaskFactory<object>.FromAsyncBeginEnd (beginMethod,
                l => { endMethod (l); return null; },
                state, creationOptions);
        }

        public Task FromAsync<TArg1> (Func<TArg1, AsyncCallback, object, IAsyncResult> beginMethod, Action<IAsyncResult> endMethod,
                                      TArg1 arg1, object state)
        {
            return FromAsync (beginMethod, endMethod, arg1, state, creationOptions);
        }

        public Task FromAsync<TArg1> (Func<TArg1, AsyncCallback, object, IAsyncResult> beginMethod, Action<IAsyncResult> endMethod,
                                      TArg1 arg1, object state, TaskCreationOptions creationOptions)
        {
            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            return TaskFactory<object>.FromAsyncBeginEnd (beginMethod,
                l => { endMethod (l); return null; },
                arg1, state, creationOptions);
        }

        public Task FromAsync<TArg1, TArg2> (Func<TArg1, TArg2, AsyncCallback, object, IAsyncResult> beginMethod,
                                             Action<IAsyncResult> endMethod,
                                             TArg1 arg1, TArg2 arg2, object state)
        {
            return FromAsync (beginMethod, endMethod, arg1, arg2, state, creationOptions);
        }

        public Task FromAsync<TArg1, TArg2> (Func<TArg1, TArg2, AsyncCallback, object, IAsyncResult> beginMethod,
                                             Action<IAsyncResult> endMethod,
                                             TArg1 arg1, TArg2 arg2, object state, TaskCreationOptions creationOptions)
        {
            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            return TaskFactory<object>.FromAsyncBeginEnd (beginMethod,
                l => { endMethod (l); return null; },
                arg1, arg2, state, creationOptions);
        }

        public Task FromAsync<TArg1, TArg2, TArg3> (Func<TArg1, TArg2, TArg3, AsyncCallback, object, IAsyncResult> beginMethod, Action<IAsyncResult> endMethod,
                                                    TArg1 arg1, TArg2 arg2, TArg3 arg3, object state)
        {
            return FromAsync (beginMethod, endMethod, arg1, arg2, arg3, state, creationOptions);
        }

        public Task FromAsync<TArg1, TArg2, TArg3> (Func<TArg1, TArg2, TArg3, AsyncCallback, object, IAsyncResult> beginMethod, Action<IAsyncResult> endMethod,
                                                    TArg1 arg1, TArg2 arg2, TArg3 arg3, object state, TaskCreationOptions creationOptions)
        {
            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            return TaskFactory<object>.FromAsyncBeginEnd (beginMethod,
                l => { endMethod (l); return null; },
                arg1, arg2, arg3, state, creationOptions);
        }

        public Task<TResult> FromAsync<TResult> (Func<AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                 object state)
        {
            return FromAsync (beginMethod, endMethod, state, creationOptions);
        }

        public Task<TResult> FromAsync<TResult> (Func<AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                 object state, TaskCreationOptions creationOptions)
        {
            return TaskFactory<TResult>.FromAsyncBeginEnd (beginMethod, endMethod, state, creationOptions);
        }

        public Task<TResult> FromAsync<TArg1, TResult> (Func<TArg1, AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                        TArg1 arg1, object state)
        {
            return FromAsync (beginMethod, endMethod, arg1, state, creationOptions);
        }

        public Task<TResult> FromAsync<TArg1, TResult> (Func<TArg1, AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                        TArg1 arg1, object state, TaskCreationOptions creationOptions)
        {
            return TaskFactory<TResult>.FromAsyncBeginEnd (beginMethod, endMethod, arg1, state, creationOptions);
        }

        public Task<TResult> FromAsync<TArg1, TArg2, TResult> (Func<TArg1, TArg2, AsyncCallback, object, IAsyncResult> beginMethod,
                                                               Func<IAsyncResult, TResult> endMethod,
                                                               TArg1 arg1, TArg2 arg2, object state)
        {
            return FromAsync (beginMethod, endMethod, arg1, arg2, state, creationOptions);
        }

        public Task<TResult> FromAsync<TArg1, TArg2, TResult> (Func<TArg1, TArg2, AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                               TArg1 arg1, TArg2 arg2, object state, TaskCreationOptions creationOptions)
        {
            return TaskFactory<TResult>.FromAsyncBeginEnd (beginMethod, endMethod, arg1, arg2, state, creationOptions);
        }

        public Task<TResult> FromAsync<TArg1, TArg2, TArg3, TResult> (Func<TArg1, TArg2, TArg3, AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                                      TArg1 arg1, TArg2 arg2, TArg3 arg3, object state)
        {
            return FromAsync (beginMethod, endMethod, arg1, arg2, arg3, state, creationOptions);
        }

        public Task<TResult> FromAsync<TArg1, TArg2, TArg3, TResult> (Func<TArg1, TArg2, TArg3, AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                                      TArg1 arg1, TArg2 arg2, TArg3 arg3, object state, TaskCreationOptions creationOptions)
        {
            return TaskFactory<TResult>.FromAsyncBeginEnd (beginMethod, endMethod, arg1, arg2, arg3, state, creationOptions);
        }

        #endregion

        TaskScheduler GetScheduler ()
        {
            return scheduler ?? TaskScheduler.Current;
        }

        static void CheckContinueArguments (Task[] tasks, object continuationAction, TaskContinuationOptions continuationOptions, TaskScheduler scheduler)
        {
            if (tasks == null)
                throw new ArgumentNullException ("tasks");

            if (tasks.Length == 0)
                throw new ArgumentException ("The tasks argument contains no tasks", "tasks");

            foreach (var ta in tasks) {
                if (ta == null)
                    throw new ArgumentException ("The tasks argument contains a null value", "tasks");
            }

            if (continuationAction == null)
                throw new ArgumentNullException ("continuationAction");
            if (scheduler == null)
                throw new ArgumentNullException ("scheduler");

            const TaskContinuationOptions notAllowedOptions = 
                TaskContinuationOptions.NotOnRanToCompletion  |
                TaskContinuationOptions.NotOnFaulted |
                TaskContinuationOptions.NotOnCanceled |
                TaskContinuationOptions.OnlyOnRanToCompletion |
                TaskContinuationOptions.OnlyOnFaulted |
                TaskContinuationOptions.OnlyOnCanceled;

            if ((continuationOptions & notAllowedOptions) != 0)
                throw new ArgumentOutOfRangeException ("continuationOptions");
        }
    }
}
#endif