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#if NET20 || NET30 || NET35 || !NET_4_6
using System.Collections.Generic;
using System.Runtime.CompilerServices;
namespace System.Threading.Tasks
{
/// <summary>
/// Provides methods for creating and manipulating tasks.
/// </summary>
///
/// <remarks>
/// TaskEx is a placeholder.
/// </remarks>
public static class TaskEx
{
/// <summary>
/// Starts a Task that will complete after the specified due time.
/// </summary>
/// <param name="dueTime">The delay in milliseconds before the returned task completes.</param>
/// <returns>
/// The timed Task.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="dueTime"/> argument must be non-negative or -1 and less than or equal to Int32.MaxValue.
/// </exception>
public static Task Delay(int dueTime)
{
return Delay(dueTime, CancellationToken.None);
}
/// <summary>
/// Starts a Task that will complete after the specified due time.
/// </summary>
/// <param name="dueTime">The delay before the returned task completes.</param>
/// <returns>
/// The timed Task.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="dueTime"/> argument must be non-negative or -1 and less than or equal to Int32.MaxValue.
/// </exception>
public static Task Delay(TimeSpan dueTime)
{
return Delay(dueTime, CancellationToken.None);
}
/// <summary>
/// Starts a Task that will complete after the specified due time.
/// </summary>
/// <param name="dueTime">The delay before the returned task completes.</param><param name="cancellationToken">A CancellationToken that may be used to cancel the task before the due time occurs.</param>
/// <returns>
/// The timed Task.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="dueTime"/> argument must be non-negative or -1 and less than or equal to Int32.MaxValue.
/// </exception>
public static Task Delay(TimeSpan dueTime, CancellationToken cancellationToken)
{
return Task.Delay(dueTime, cancellationToken);
}
/// <summary>
/// Starts a Task that will complete after the specified due time.
/// </summary>
/// <param name="dueTime">The delay in milliseconds before the returned task completes.</param><param name="cancellationToken">A CancellationToken that may be used to cancel the task before the due time occurs.</param>
/// <returns>
/// The timed Task.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="dueTime"/> argument must be non-negative or -1 and less than or equal to Int32.MaxValue.
/// </exception>
public static Task Delay(int dueTime, CancellationToken cancellationToken)
{
return Task.Delay(dueTime, cancellationToken);
}
/// <summary>
/// Creates an already completed <see cref="T:System.Threading.Tasks.Task`1"/> from the specified result.
/// </summary>
/// <param name="result">The result from which to create the completed task.</param>
/// <returns>
/// The completed task.
/// </returns>
public static Task<TResult> FromResult<TResult>(TResult result)
{
return Task.FromResult(result);
}
/// <summary>
/// Creates a task that runs the specified action.
/// </summary>
/// <param name="action">The action to execute asynchronously.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="action"/> argument is null.</exception>
public static Task Run(Action action)
{
return Run(action, CancellationToken.None);
}
/// <summary>
/// Creates a task that runs the specified action.
/// </summary>
/// <param name="action">The action to execute.</param><param name="cancellationToken">The CancellationToken to use to request cancellation of this task.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="action"/> argument is null.</exception>
public static Task Run(Action action, CancellationToken cancellationToken)
{
return Task.Factory.StartNew(action, cancellationToken, TaskCreationOptions.None, TaskScheduler.Default);
}
/// <summary>
/// Creates a task that runs the specified function.
/// </summary>
/// <param name="function">The function to execute asynchronously.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="function"/> argument is null.</exception>
public static Task<TResult> Run<TResult>(Func<TResult> function)
{
return Run(function, CancellationToken.None);
}
/// <summary>
/// Creates a task that runs the specified function.
/// </summary>
/// <param name="function">The action to execute.</param><param name="cancellationToken">The CancellationToken to use to cancel the task.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="function"/> argument is null.</exception>
public static Task<TResult> Run<TResult>(Func<TResult> function, CancellationToken cancellationToken)
{
return Task.Factory.StartNew(function, cancellationToken, TaskCreationOptions.None, TaskScheduler.Default);
}
/// <summary>
/// Creates a task that runs the specified function.
/// </summary>
/// <param name="function">The action to execute asynchronously.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="function"/> argument is null.</exception>
public static Task Run(Func<Task> function)
{
return Run(function, CancellationToken.None);
}
/// <summary>
/// Creates a task that runs the specified function.
/// </summary>
/// <param name="function">The function to execute.</param><param name="cancellationToken">The CancellationToken to use to request cancellation of this task.</param>
/// <returns>
/// A task that represents the completion of the function.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="function"/> argument is null.</exception>
public static Task Run(Func<Task> function, CancellationToken cancellationToken)
{
return Run<Task>(function, cancellationToken).Unwrap();
}
/// <summary>
/// Creates a task that runs the specified function.
/// </summary>
/// <param name="function">The function to execute asynchronously.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="function"/> argument is null.</exception>
public static Task<TResult> Run<TResult>(Func<Task<TResult>> function)
{
return Run(function, CancellationToken.None);
}
/// <summary>
/// Creates a task that runs the specified function.
/// </summary>
/// <param name="function">The action to execute.</param><param name="cancellationToken">The CancellationToken to use to cancel the task.</param>
/// <returns>
/// A task that represents the completion of the action.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="function"/> argument is null.</exception>
public static Task<TResult> Run<TResult>(Func<Task<TResult>> function, CancellationToken cancellationToken)
{
return Run<Task<TResult>>(function, cancellationToken).Unwrap();
}
/// <summary>
/// Creates a Task that will complete only when all of the provided collection of Tasks has completed.
/// </summary>
/// <param name="tasks">The Tasks to monitor for completion.</param>
/// <returns>
/// A Task that represents the completion of all of the provided tasks.
/// </returns>
///
/// <remarks>
/// If any of the provided Tasks faults, the returned Task will also fault, and its Exception will contain information
/// about all of the faulted tasks. If no Tasks fault but one or more Tasks is canceled, the returned
/// Task will also be canceled.
///
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task WhenAll(params Task[] tasks)
{
return WhenAll((IEnumerable<Task>)tasks);
}
/// <summary>
/// Creates a Task that will complete only when all of the provided collection of Tasks has completed.
/// </summary>
/// <param name="tasks">The Tasks to monitor for completion.</param>
/// <returns>
/// A Task that represents the completion of all of the provided tasks.
/// </returns>
///
/// <remarks>
/// If any of the provided Tasks faults, the returned Task will also fault, and its Exception will contain information
/// about all of the faulted tasks. If no Tasks fault but one or more Tasks is canceled, the returned
/// Task will also be canceled.
///
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task<TResult[]> WhenAll<TResult>(params Task<TResult>[] tasks)
{
return WhenAll((IEnumerable<Task<TResult>>)tasks);
}
/// <summary>
/// Creates a Task that will complete only when all of the provided collection of Tasks has completed.
/// </summary>
/// <param name="tasks">The Tasks to monitor for completion.</param>
/// <returns>
/// A Task that represents the completion of all of the provided tasks.
/// </returns>
///
/// <remarks>
/// If any of the provided Tasks faults, the returned Task will also fault, and its Exception will contain information
/// about all of the faulted tasks. If no Tasks fault but one or more Tasks is canceled, the returned
/// Task will also be canceled.
///
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task WhenAll(IEnumerable<Task> tasks)
{
return Task.WhenAll(tasks);
}
/// <summary>
/// Creates a Task that will complete only when all of the provided collection of Tasks has completed.
/// </summary>
/// <param name="tasks">The Tasks to monitor for completion.</param>
/// <returns>
/// A Task that represents the completion of all of the provided tasks.
/// </returns>
///
/// <remarks>
/// If any of the provided Tasks faults, the returned Task will also fault, and its Exception will contain information
/// about all of the faulted tasks. If no Tasks fault but one or more Tasks is canceled, the returned
/// Task will also be canceled.
///
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task<TResult[]> WhenAll<TResult>(IEnumerable<Task<TResult>> tasks)
{
return Task.WhenAll(tasks);
}
/// <summary>
/// Creates a Task that will complete when any of the tasks in the provided collection completes.
/// </summary>
/// <param name="tasks">The Tasks to be monitored.</param>
/// <returns>
/// A Task that represents the completion of any of the provided Tasks. The completed Task is this Task's result.
///
/// </returns>
///
/// <remarks>
/// Any Tasks that fault will need to have their exceptions observed elsewhere.
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task<Task> WhenAny(params Task[] tasks)
{
return WhenAny((IEnumerable<Task>)tasks);
}
/// <summary>
/// Creates a Task that will complete when any of the tasks in the provided collection completes.
/// </summary>
/// <param name="tasks">The Tasks to be monitored.</param>
/// <returns>
/// A Task that represents the completion of any of the provided Tasks. The completed Task is this Task's result.
///
/// </returns>
///
/// <remarks>
/// Any Tasks that fault will need to have their exceptions observed elsewhere.
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task<Task> WhenAny(IEnumerable<Task> tasks)
{
return Task.WhenAny(tasks);
}
/// <summary>
/// Creates a Task that will complete when any of the tasks in the provided collection completes.
/// </summary>
/// <param name="tasks">The Tasks to be monitored.</param>
/// <returns>
/// A Task that represents the completion of any of the provided Tasks. The completed Task is this Task's result.
///
/// </returns>
///
/// <remarks>
/// Any Tasks that fault will need to have their exceptions observed elsewhere.
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task<Task<TResult>> WhenAny<TResult>(params Task<TResult>[] tasks)
{
return WhenAny((IEnumerable<Task<TResult>>)tasks);
}
/// <summary>
/// Creates a Task that will complete when any of the tasks in the provided collection completes.
/// </summary>
/// <param name="tasks">The Tasks to be monitored.</param>
/// <returns>
/// A Task that represents the completion of any of the provided Tasks. The completed Task is this Task's result.
///
/// </returns>
///
/// <remarks>
/// Any Tasks that fault will need to have their exceptions observed elsewhere.
/// </remarks>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="tasks"/> argument is null.</exception><exception cref="T:System.ArgumentException">The <paramref name="tasks"/> argument contains a null reference.</exception>
public static Task<Task<TResult>> WhenAny<TResult>(IEnumerable<Task<TResult>> tasks)
{
return Task.WhenAny(tasks);
}
/// <summary>
/// Creates an awaitable that asynchronously yields back to the current context when awaited.
/// </summary>
///
/// <returns>
/// A context that, when awaited, will asynchronously transition back into the current context.
/// If SynchronizationContext.Current is non-null, that is treated as the current context.
/// Otherwise, TaskScheduler.Current is treated as the current context.
///
/// </returns>
public static YieldAwaitable Yield()
{
return new YieldAwaitable();
}
}
}
#endif