TaskFactory_T.cs

Go to the documentation of this file.

// 
// TaskFactory_T.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<TResult>
    {
        readonly TaskScheduler scheduler;
        TaskCreationOptions creationOptions;
        TaskContinuationOptions continuationOptions;
        CancellationToken cancellationToken;
        
        TaskFactory parent;

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

            TaskFactory.CheckContinuationOptions (continuationOptions);
            
            this.parent = new TaskFactory (cancellationToken, creationOptions, continuationOptions, scheduler);
        }

        public TaskScheduler Scheduler {
            get {
                return scheduler;
            }
        }
        
        public TaskContinuationOptions ContinuationOptions {
            get {
                return continuationOptions;
            }
        }
        
        public TaskCreationOptions CreationOptions {
            get {
                return creationOptions;
            }
        }
        
        public CancellationToken CancellationToken {
            get {
                return cancellationToken;
            }
        }
        
        #region StartNew for Task<TResult>  
        public Task<TResult> StartNew (Func<TResult> function)
        {
            return StartNew (function, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew (Func<TResult> function, TaskCreationOptions creationOptions)
        {
            return StartNew (function, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew (Func<TResult> function, CancellationToken cancellationToken)
        {
            return StartNew (function, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew (Func<TResult> function, 
                                       CancellationToken cancellationToken,
                                       TaskCreationOptions creationOptions,
                                       TaskScheduler scheduler)
        {
            return StartNew ((o) => function (), null, cancellationToken, creationOptions, scheduler);
        }
        
        public Task<TResult> StartNew (Func<object, TResult> function, object state)
        {
            return StartNew (function, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew (Func<object, TResult> function, object state, TaskCreationOptions creationOptions)
        {
            return StartNew (function, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew (Func<object, TResult> function, object state, CancellationToken cancellationToken)
        {
            return StartNew (function, state, cancellationToken, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> StartNew (Func<object, TResult> function, object state, 
                                       CancellationToken cancellationToken,
                                       TaskCreationOptions creationOptions,
                                       TaskScheduler scheduler)
        {
            return parent.StartNew<TResult> (function, state, cancellationToken, creationOptions, scheduler);
        }
        #endregion
        
        #region Continue

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

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

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

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

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

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

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

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

        #endregion
        
        #region FromAsync
        
        public Task<TResult> FromAsync (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod)
        {
            return FromAsync (asyncResult, endMethod, creationOptions);
        }
        
        public Task<TResult> FromAsync (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod, TaskCreationOptions creationOptions)
        {
            return FromAsync (asyncResult, endMethod, creationOptions, GetScheduler ());
        }
        
        public Task<TResult> FromAsync (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod, TaskCreationOptions creationOptions, TaskScheduler scheduler)
        {
            return FromIAsyncResult (asyncResult, endMethod, creationOptions, scheduler);
        }

        internal static Task<TResult> FromIAsyncResult (IAsyncResult asyncResult, Func<IAsyncResult, TResult> endMethod, TaskCreationOptions creationOptions, TaskScheduler scheduler)
        {
            if (asyncResult == null)
                throw new ArgumentNullException ("asyncResult");

            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

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

            if ((creationOptions & Task.WorkerTaskNotSupportedOptions) != 0)
                throw new ArgumentOutOfRangeException ("creationOptions");

            var source = new CancellationTokenSource ();
            var task = new Task<TResult> (l => {
                try {
                    return endMethod (asyncResult);
                } catch (OperationCanceledException) {
                    source.Cancel ();
                    source.Token.ThrowIfCancellationRequested ();
                }
                return default (TResult);
            }, null, source.Token, creationOptions);

            // Take quick path for completed operations
            if (asyncResult.IsCompleted) {
                task.RunSynchronously (scheduler);
            } else {
                ThreadPool.RegisterWaitForSingleObject (asyncResult.AsyncWaitHandle,
                                                        (s, t) => task.RunSynchronously (scheduler),
                                                        null, Timeout.Infinite, true);
            }

            return task;
        }

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

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

        internal static Task<TResult> FromAsyncBeginEnd (Func<AsyncCallback, object, IAsyncResult> beginMethod, Func<IAsyncResult, TResult> endMethod,
                                                         object state, TaskCreationOptions creationOptions)
        {
            if (beginMethod == null)
                throw new ArgumentNullException ("beginMethod");

            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            if ((creationOptions & Task.WorkerTaskNotSupportedOptions) != 0)
                throw new ArgumentOutOfRangeException ("creationOptions");

            var tcs = new TaskCompletionSource<TResult> (state, creationOptions);
            var alreadyInvoked = new AtomicBoolean ();
            var iar = beginMethod (l => {
                if (alreadyInvoked.TryRelaxedSet ())
                    InnerInvoke (tcs, endMethod, l);
            }, state);
            if (iar != null && iar.CompletedSynchronously && alreadyInvoked.TryRelaxedSet ())
                InnerInvoke (tcs, endMethod, iar);

            return tcs.Task;
        }

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

        internal static Task<TResult> FromAsyncBeginEnd<TArg1> (Func<TArg1, AsyncCallback, object, IAsyncResult> beginMethod,
                                                                Func<IAsyncResult, TResult> endMethod,
                                                                TArg1 arg1, object state, TaskCreationOptions creationOptions)
        {
            if (beginMethod == null)
                throw new ArgumentNullException ("beginMethod");

            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            if ((creationOptions & Task.WorkerTaskNotSupportedOptions) != 0)
                throw new ArgumentOutOfRangeException ("creationOptions");

            var tcs = new TaskCompletionSource<TResult> (state, creationOptions);
            var alreadyInvoked = new AtomicBoolean ();
            var iar = beginMethod (arg1, l => {
                if (alreadyInvoked.TryRelaxedSet ())
                    InnerInvoke (tcs, endMethod, l);
            }, state);
            if (iar != null && iar.CompletedSynchronously && alreadyInvoked.TryRelaxedSet ())
                InnerInvoke (tcs, endMethod, iar);

            return tcs.Task;
        }

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

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

            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            if ((creationOptions & Task.WorkerTaskNotSupportedOptions) != 0)
                throw new ArgumentOutOfRangeException ("creationOptions");

            var tcs = new TaskCompletionSource<TResult> (state, creationOptions);
            var alreadyInvoked = new AtomicBoolean ();
            var iar = beginMethod (arg1, arg2, l => {
                if (alreadyInvoked.TryRelaxedSet ())
                    InnerInvoke (tcs, endMethod, l);
            }, state);
            if (iar != null && iar.CompletedSynchronously && alreadyInvoked.TryRelaxedSet ())
                InnerInvoke (tcs, endMethod, iar);

            return tcs.Task;
        }

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

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

            if (endMethod == null)
                throw new ArgumentNullException ("endMethod");

            if ((creationOptions & Task.WorkerTaskNotSupportedOptions) != 0)
                throw new ArgumentOutOfRangeException ("creationOptions");

            var tcs = new TaskCompletionSource<TResult> (state, creationOptions);
            var alreadyInvoked = new AtomicBoolean ();
            var iar = beginMethod (arg1, arg2, arg3, l => {
                if (alreadyInvoked.TryRelaxedSet ())
                    InnerInvoke (tcs, endMethod, l);
            }, state);
            if (iar != null && iar.CompletedSynchronously && alreadyInvoked.TryRelaxedSet ())
                InnerInvoke (tcs, endMethod, iar);

            return tcs.Task;
        }

        #endregion

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

        static void InnerInvoke (TaskCompletionSource<TResult> tcs, Func<IAsyncResult, TResult> endMethod, IAsyncResult l)
        {
            try {
                tcs.SetResult (endMethod (l));
            } catch (OperationCanceledException) {
                tcs.SetCanceled ();
            } catch (Exception e) {
                tcs.SetException (e);
            }
        }
    }
}
#endif