ParallelAlgorithms_SpeculativeInvoke.cs

//
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE.md file in the project root for full license information.
//

using System.Threading.Tasks;

namespace System.Threading.Algorithms
{
    public static partial class ParallelAlgorithms
    {
        /// <summary>Invokes the specified functions, potentially in parallel, canceling outstanding invocations once one completes.</summary>
        /// <typeparam name="T">Specifies the type of data returned by the functions.</typeparam>
        /// <param name="functions">The functions to be executed.</param>
        /// <returns>A result from executing one of the functions.</returns>
        public static T SpeculativeInvoke<T>(params Func<T>[] functions) =>
            SpeculativeInvoke(s_defaultParallelOptions, functions);

        /// <summary>Invokes the specified functions, potentially in parallel, canceling outstanding invocations once one completes.</summary>
        /// <typeparam name="T">Specifies the type of data returned by the functions.</typeparam>
        /// <param name="options">The options to use for the execution.</param>
        /// <param name="functions">The functions to be executed.</param>
        /// <returns>A result from executing one of the functions.</returns>
        public static T SpeculativeInvoke<T>(ParallelOptions options, params Func<T>[] functions)
        {
            // Validate parameters
            if (options == null) throw new ArgumentNullException(nameof(options));
            if (functions == null) throw new ArgumentNullException(nameof(functions));

            // Speculatively invoke each function
            return SpeculativeForEach(functions, options, function => function());
        }
    }
}