developer/Samples/NET 4.6/Samples for Parallel/ParallelExtensionsExtras/Extensions/DelegateExtensions.cs

   1 //--------------------------------------------------------------------------
   2 //
   3 //  Copyright (c) Microsoft Corporation.  All rights reserved.
   4 //
   5 //  File: DelegateExtensions.cs
   6 //
   7 //--------------------------------------------------------------------------
   8
   9 using System.Diagnostics;
  10 using System.Linq;
  11
  12 namespace System
  13 {
  14     /// <summary>Parallel extensions for the Delegate class.</summary>
  15     public static class DelegateExtensions
  16     {
  17         /// <summary>Dynamically invokes (late-bound) in parallel the methods represented by the delegate.</summary>
  18         /// <param name="multicastDelegate">The delegate to be invoked.</param>
  19         /// <param name="args">An array of objects that are the arguments to pass to the delegates.</param>
  20         /// <returns>The return value of one of the delegate invocations.</returns>
  21         public static object ParallelDynamicInvoke(this Delegate multicastDelegate, params object[] args)
  22         {
  23             if (multicastDelegate == null) throw new ArgumentNullException("multicastDelegate");
  24             if (args == null) throw new ArgumentNullException("args");
  25             return multicastDelegate.GetInvocationList()
  26                    .AsParallel().AsOrdered()
  27                    .Select(d => d.DynamicInvoke(args))
  28                    .Last();
  29         }
  30
  31         /// <summary>
  32         /// Provides a delegate that runs the specified action and fails fast if the action throws an exception.
  33         /// </summary>
  34         /// <param name="action">The action to invoke.</param>
  35         /// <returns>The wrapper delegate.</returns>
  36         public static Action WithFailFast(this Action action)
  37         {
  38             return () =>
  39             {
  40                 try { action(); }
  41                 catch (Exception exc)
  42                 {
  43                     if (Debugger.IsAttached) Debugger.Break();
  44                     else Environment.FailFast("An unhandled exception occurred.", exc);
  45                 }
  46             };
  47         }
  48
  49         /// <summary>
  50         /// Provides a delegate that runs the specified function and fails fast if the function throws an exception.
  51         /// </summary>
  52         /// <param name="function">The function to invoke.</param>
  53         /// <returns>The wrapper delegate.</returns>
  54         public static Func<T> WithFailFast<T>(this Func<T> function)
  55         {
  56             return () =>
  57             {
  58                 try { return function(); }
  59                 catch (Exception exc)
  60                 {
  61                     if (Debugger.IsAttached) Debugger.Break();
  62                     else Environment.FailFast("An unhandled exception occurred.", exc);
  63                 }
  64                 throw new Exception("Will never get here");
  65             };
  66         }
  67     }
  68 }