PowerProcess

0.0.1

Nito.AsyncEx.Context/TaskExtensions.cs

using System;
using System.Threading;
using System.Threading.Tasks;

namespace Nito.AsyncEx.Synchronous
{
    /// <summary>
    /// Provides synchronous extension methods for tasks.
    /// </summary>
    public static class TaskExtensions
    {
        /// <summary>
        /// Waits for the task to complete, unwrapping any exceptions.
        /// </summary>
        /// <param name="task">The task. May not be <c>null</c>.</param>
        /// <param name="cancellationToken">A cancellation token to observe while waiting for the task to complete.</param>
        /// <exception cref="OperationCanceledException">The <paramref name="cancellationToken"/> was cancelled before the <paramref name="task"/> completed, or the <paramref name="task"/> raised an <see cref="OperationCanceledException"/>.</exception>
        public static void WaitAndUnwrapException(this Task task, CancellationToken? cancellationToken = null)
        {
            if (task == null)
                throw new ArgumentNullException(nameof(task));
            try
            {
                if (cancellationToken == null)
                {

                    task.GetAwaiter().GetResult();
                }
                else
                {
                    var ct = cancellationToken ?? throw new NullReferenceException();
                    task.Wait(ct);
                }
            }
            catch (AggregateException ex)
            {
                throw ExceptionHelpers.PrepareForRethrow(ex.InnerException ?? ex);
            }
        }

        /// <summary>
        /// Waits for the task to complete, unwrapping any exceptions.
        /// </summary>
        /// <typeparam name="TResult">The type of the result of the task.</typeparam>
        /// <param name="task">The task. May not be <c>null</c>.</param>
        /// <param name="cancellationToken">A cancellation token to observe while waiting for the task to complete.</param>
        /// <returns>The result of the task.</returns>
        /// <exception cref="OperationCanceledException">The <paramref name="cancellationToken"/> was cancelled before the <paramref name="task"/> completed, or the <paramref name="task"/> raised an <see cref="OperationCanceledException"/>.</exception>
        public static TResult WaitAndUnwrapException<TResult>(this Task<TResult> task, CancellationToken? cancellationToken = null)
        {
            if (task == null)
                throw new ArgumentNullException(nameof(task));
            try
            {
                if (cancellationToken == null)
                {
                    return task.GetAwaiter().GetResult();
                }
                else
                {
                    var ct = cancellationToken ?? throw new NullReferenceException();
                    task.Wait(ct);
                    return task.Result;
                }
            }
            catch (AggregateException ex)
            {
                throw ExceptionHelpers.PrepareForRethrow(ex.InnerException ?? ex);
            }
        }

        /// <summary>
        /// Waits for the task to complete, but does not raise task exceptions. The task exception (if any) is unobserved.
        /// </summary>
        /// <param name="task">The task. May not be <c>null</c>.</param>
        /// <param name="cancellationToken">A cancellation token to observe while waiting for the task to complete.</param>
        /// <exception cref="OperationCanceledException">The <paramref name="cancellationToken"/> was cancelled before the <paramref name="task"/> completed.</exception>
        public static void WaitWithoutException(this Task task, CancellationToken? cancellationToken = null)
        {
            if (task == null)
                throw new ArgumentNullException(nameof(task));
            try
            {
                if (cancellationToken == null)
                {
                    task.Wait();
                }
                else
                {
                    var ct = cancellationToken ?? throw new NullReferenceException();
                    task.Wait(ct);
                }
            }
            catch (AggregateException)
            {
                cancellationToken?.ThrowIfCancellationRequested();
            }
        }
    }
}