Cómo: Usar Parallel.Invoke para ejecutar operaciones paralelasHow to: Use Parallel.Invoke to Execute Parallel Operations

En este ejemplo se muestra cómo paralelizar operaciones usando Invoke en la biblioteca TPL.This example shows how to parallelize operations by using Invoke in the Task Parallel Library. Se realizan tres operaciones en un origen de datos compartido.Three operations are performed on a shared data source. Como ninguna de ellas modifica el origen, se pueden ejecutar en paralelo de manera sencilla.Because none of the operations modifies the source, they can be executed in parallel in a straightforward manner.

Nota

En esta documentación, se utilizan expresiones lambda para definir delegados en la TPL.This documentation uses lambda expressions to define delegates in TPL. Si no está familiarizado con las expresiones lambda de C# o Visual Basic, consulte Lambda Expressions in PLINQ and TPL (Expresiones lambda en PLINQ y TPL).If you are not familiar with lambda expressions in C# or Visual Basic, see Lambda Expressions in PLINQ and TPL.

EjemploExample

namespace ParallelTasks
{
    using System;
    using System.IO;
    using System.Linq;
    using System.Text;
    using System.Threading;
    using System.Threading.Tasks;
    using System.Net;

    class ParallelInvoke
    {
        static void Main()
        {
            // Retrieve Goncharov's "Oblomov" from Gutenberg.org.
            string[] words = CreateWordArray(@"http://www.gutenberg.org/files/54700/54700-0.txt");

            #region ParallelTasks
            // Perform three tasks in parallel on the source array
            Parallel.Invoke(() =>
                             {
                                 Console.WriteLine("Begin first task...");
                                 GetLongestWord(words);
                             },  // close first Action

                             () =>
                             {
                                 Console.WriteLine("Begin second task...");
                                 GetMostCommonWords(words);
                             }, //close second Action

                             () =>
                             {
                                 Console.WriteLine("Begin third task...");
                                 GetCountForWord(words, "sleep");
                             } //close third Action
                         ); //close parallel.invoke

            Console.WriteLine("Returned from Parallel.Invoke");
            #endregion

            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }

        #region HelperMethods
        private static void GetCountForWord(string[] words, string term)
        {
            var findWord = from word in words
                           where word.ToUpper().Contains(term.ToUpper())
                           select word;

            Console.WriteLine($@"Task 3 -- The word ""{term}"" occurs {findWord.Count()} times.");
        }

        private static void GetMostCommonWords(string[] words)
        {
            var frequencyOrder = from word in words
                                 where word.Length > 6
                                 group word by word into g
                                 orderby g.Count() descending
                                 select g.Key;

            var commonWords = frequencyOrder.Take(10);

            StringBuilder sb = new StringBuilder();
            sb.AppendLine("Task 2 -- The most common words are:");
            foreach (var v in commonWords)
            {
                sb.AppendLine("  " + v);
            }
            Console.WriteLine(sb.ToString());
        }

        private static string GetLongestWord(string[] words)
        {
            var longestWord = (from w in words
                               orderby w.Length descending
                               select w).First();

            Console.WriteLine($"Task 1 -- The longest word is {longestWord}.");
            return longestWord;
        }

        // An http request performed synchronously for simplicity.
        static string[] CreateWordArray(string uri)
        {
            Console.WriteLine($"Retrieving from {uri}");

            // Download a web page the easy way.
            string s = new WebClient().DownloadString(uri);

            // Separate string into an array of words, removing some common punctuation.
            return s.Split(
                new char[] { ' ', '\u000A', ',', '.', ';', ':', '-', '_', '/' },
                StringSplitOptions.RemoveEmptyEntries);
        }
        #endregion
    }
}
//        The example displays output like the following:
//              Retrieving from http://www.gutenberg.org/files/54700/54700-0.txt
//              Begin first task...
//              Begin second task...
//              Begin third task...
//              Task 2 -- The most common words are:
//              Oblomov
//              himself
//              Schtoltz
//              Gutenberg
//              Project
//              another
//              thought
//              Oblomov's
//              nothing
//              replied
//       
//              Task 1 -- The longest word is incomprehensible.
//              Task 3 -- The word "sleep" occurs 57 times.
//              Returned from Parallel.Invoke
//              Press any key to exit
Imports System.Net
Imports System.Threading.Tasks

Module ParallelTasks
    Sub Main()
        ' Retrieve Goncharov's "Oblomov" from Gutenberg.org.
        Dim words As String() = CreateWordArray("http://www.gutenberg.org/files/54700/54700-0.txt")

        '#Region "ParallelTasks"
        ' Perform three tasks in parallel on the source array
        Parallel.Invoke(Sub()
                            Console.WriteLine("Begin first task...")
                            GetLongestWord(words)
                            ' close first Action
                        End Sub,
            Sub()
                Console.WriteLine("Begin second task...")
                GetMostCommonWords(words)
                'close second Action
            End Sub,
            Sub()
                Console.WriteLine("Begin third task...")
                GetCountForWord(words, "sleep")
                'close third Action
            End Sub)
        'close parallel.invoke
        Console.WriteLine("Returned from Parallel.Invoke")
        '#End Region

        Console.WriteLine("Press any key to exit")
        Console.ReadKey()
    End Sub

#Region "HelperMethods"
    Sub GetCountForWord(ByVal words As String(), ByVal term As String)
        Dim findWord = From word In words 
            Where word.ToUpper().Contains(term.ToUpper()) 
            Select word

        Console.WriteLine($"Task 3 -- The word ""{term}"" occurs {findWord.Count()} times.")
    End Sub

    Sub GetMostCommonWords(ByVal words As String())
        Dim frequencyOrder = From word In words 
            Where word.Length > 6 
            Group By word
            Into wordGroup = Group, Count()
            Order By wordGroup.Count() Descending 
            Select wordGroup

        Dim commonWords = From grp In frequencyOrder
                          Select grp
                          Take (10)

        Dim s As String
        s = "Task 2 -- The most common words are:" & vbCrLf
        For Each v In commonWords
            s = s & v(0) & vbCrLf
        Next
        Console.WriteLine(s)
    End Sub

    Function GetLongestWord(ByVal words As String()) As String
        Dim longestWord = (From w In words 
            Order By w.Length Descending 
            Select w).First()

        Console.WriteLine($"Task 1 -- The longest word is {longestWord}.")
        Return longestWord
    End Function


    ' An http request performed synchronously for simplicity.
    Function CreateWordArray(ByVal uri As String) As String()
        Console.WriteLine($"Retrieving from {uri}")

        ' Download a web page the easy way.
        Dim s As String = New WebClient().DownloadString(uri)

        ' Separate string into an array of words, removing some common punctuation.
        Return s.Split(New Char() {" "c, ControlChars.Lf, ","c, "."c, ";"c, ":"c, 
        "-"c, "_"c, "/"c}, StringSplitOptions.RemoveEmptyEntries)
    End Function
#End Region
End Module
' The exmaple displays output like the following:
'       Retrieving from http://www.gutenberg.org/files/54700/54700-0.txt
'       Begin first task...
'       Begin second task...
'       Begin third task...
'       Task 2 -- The most common words are:
'       Oblomov
'       himself
'       Schtoltz
'       Gutenberg
'       Project
'       another
'       thought
'       Oblomov's
'       nothing
'       replied
'
'       Task 1 -- The longest word is incomprehensible.
'       Task 3 -- The word "sleep" occurs 57 times.
'       Returned from Parallel.Invoke
'       Press any key to exit

Tenga en cuenta que con Invoke, solo tiene que expresar qué acciones quiere ejecutar simultáneamente y el tiempo de ejecución controla todos los detalles de programación de los subprocesos, incluido el ajuste automático del número de núcleos en el equipo host.Note that with Invoke, you simply express which actions you want to run concurrently, and the runtime handles all thread scheduling details, including scaling automatically to the number of cores on the host computer.

En este ejemplo se paralelizan las operaciones, no los datos.This example parallelizes the operations, not the data. Como método alternativo, puede paralelizar los consultas de LINQ mediante PLINQ y ejecutar las consultas de forma secuencial.As an alternate approach, you can parallelize the LINQ queries by using PLINQ and run the queries sequentially. También puede paralelizar los datos con PLINQ.Alternatively, you could parallelize the data by using PLINQ. Otra opción consiste en paralelizar las consultas y las tareas.Another option is to parallelize both the queries and the tasks. Aunque la sobrecarga resultante podría reducir el rendimiento en equipos host con relativamente pocos procesadores, se ajustaría mucho mejor en equipos con varios procesadores.Although the resulting overhead might degrade performance on host computers with relatively few processors, it would scale much better on computers with many processors.

Compilar el códigoCompile the Code

Copie y pegue el ejemplo completo en un proyecto de Microsoft Visual Studio y presione F5.Copy and paste the entire example into a Microsoft Visual Studio project and press F5.

Vea tambiénSee also