Task.WaitAll Metodo

public:
 static void WaitAll(... cli::array <System::Threading::Tasks::Task ^> ^ tasks);

public static void WaitAll(params System.Threading.Tasks.Task[] tasks);

static member WaitAll : System.Threading.Tasks.Task[] -> unit

Public Shared Sub WaitAll (ParamArray tasks As Task())

Parametri

Eccezioni

Esempio

Nell'esempio seguente vengono avviati 10 attività, ognuna delle quali viene passata un indice come oggetto stato. Le attività con un indice da due a cinque generano eccezioni. La chiamata al metodo esegue il WaitAll wrapping di tutte le eccezioni in un AggregateException oggetto e la propaga al thread chiamante.

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

class Example
{
    static void Main()
    {
        var tasks = new List<Task<int>>();
         
        // Define a delegate that prints and returns the system tick count
        Func<object, int> action = (object obj) =>
        {
            int i = (int)obj;

            // Make each thread sleep a different time in order to return a different tick count
            Thread.Sleep(i * 100);

            // The tasks that receive an argument between 2 and 5 throw exceptions
            if (2 <= i && i <= 5)
            {
                throw new InvalidOperationException("SIMULATED EXCEPTION");
            }

            int tickCount = Environment.TickCount;
            Console.WriteLine("Task={0}, i={1}, TickCount={2}, Thread={3}", Task.CurrentId, i, tickCount, Thread.CurrentThread.ManagedThreadId);

            return tickCount;
        };

        // Construct started tasks
        for (int i = 0; i < 10; i++)
        {
            int index = i;
            tasks.Add(Task<int>.Factory.StartNew(action, index));
        }

        try
        {
            // Wait for all the tasks to finish.
            Task.WaitAll(tasks.ToArray());

            // We should never get to this point
            Console.WriteLine("WaitAll() has not thrown exceptions. THIS WAS NOT EXPECTED.");
        }
        catch (AggregateException e)
        {
            Console.WriteLine("\nThe following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)");
            for (int j = 0; j < e.InnerExceptions.Count; j++)
            {
                Console.WriteLine("\n-------------------------------------------------\n{0}", e.InnerExceptions[j].ToString());
            }
        }
    }
}
// The example displays output like the following:
//     Task=1, i=0, TickCount=1203822250, Thread=3
//     Task=2, i=1, TickCount=1203822359, Thread=4
//     Task=7, i=6, TickCount=1203823484, Thread=3
//     Task=8, i=7, TickCount=1203823890, Thread=4
//     Task=9, i=8, TickCount=1203824296, Thread=3
//     Task=10, i=9, TickCount=1203824796, Thread=4
//     
//     The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()

open System
open System.Threading
open System.Threading.Tasks

// Define a delegate that prints and returns the system tick count
let action =
    fun (obj: obj) ->
        let i = obj :?> int

        // Make each thread sleep a different time in order to return a different tick count
        Thread.Sleep(i * 100)

        // The tasks that receive an argument between 2 and 5 throw exceptions
        if 2 <= i && i <= 5 then
            raise (InvalidOperationException "SIMULATED EXCEPTION")


        let tickCount = Environment.TickCount
        printfn $"Task={Task.CurrentId}, i={i}, TickCount={tickCount}, Thread={Thread.CurrentThread.ManagedThreadId}"
        tickCount

// Construct started tasks
let tasks =
    [| for i = 0 to 9 do
           Task<int>.Factory.StartNew (action, i) |]

try

    // Wait for all the tasks to finish.
    Seq.cast tasks |> Seq.toArray |> Task.WaitAll

    // We should never get to this point
    printfn "WaitAll() has not thrown exceptions. THIS WAS NOT EXPECTED."

with :? AggregateException as e ->
    printfn "\nThe following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)"

    for ex in e.InnerExceptions do
        printfn $"\n-------------------------------------------------\n{ex}"

// The example displays output like the following:
//     Task=1, i=0, TickCount=1203822250, Thread=3
//     Task=2, i=1, TickCount=1203822359, Thread=4
//     Task=7, i=6, TickCount=1203823484, Thread=3
//     Task=8, i=7, TickCount=1203823890, Thread=4
//     Task=9, i=8, TickCount=1203824296, Thread=3
//     Task=10, i=9, TickCount=1203824796, Thread=4
//
//     The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)
//
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()

Imports System.Collections.Generic
Imports System.Threading
Imports System.Threading.Tasks

Module WaitAllDemo
    Sub Main()
        Dim tasks As New List(Of Task(Of Integer))()
        ' Define a delegate that prints and returns the system tick count
        Dim action As Func(Of Object, Integer) = Function(obj As Object)
                                                     Dim i As Integer = CInt(obj)

                                                     ' Make each thread sleep a different time in order to return a different tick count
                                                     Thread.Sleep(i * 100)

                                                     ' The tasks that receive an argument between 2 and 5 throw exceptions
                                                     If 2 <= i AndAlso i <= 5 Then
                                                         Throw New InvalidOperationException("SIMULATED EXCEPTION")
                                                     End If

                                                     Dim tickCount As Integer = Environment.TickCount
                                                     Console.WriteLine("Task={0}, i={1}, TickCount={2}, Thread={3}", Task.CurrentId, i, tickCount, Thread.CurrentThread.ManagedThreadId)

                                                     Return tickCount
                                                 End Function

        ' Construct started tasks
        For i As Integer = 0 To 9
            Dim index As Integer = i
            tasks.Add(Task(Of Integer).Factory.StartNew(action, index))
        Next

        Try
            ' Wait for all the tasks to finish.
            Task.WaitAll(tasks.ToArray())

            ' We should never get to this point
            Console.WriteLine("WaitAll() has not thrown exceptions. THIS WAS NOT EXPECTED.")
        Catch e As AggregateException
            Console.WriteLine(vbLf & "The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)")
            For j As Integer = 0 To e.InnerExceptions.Count - 1
                Console.WriteLine(vbLf & "-------------------------------------------------" & vbLf & "{0}", e.InnerExceptions(j).ToString())
            Next
        End Try
    End Sub
End Module
' The example displays output like the following:
'     Task=1, i=0, TickCount=1203822250, Thread=3
'     Task=2, i=1, TickCount=1203822359, Thread=4
'     Task=7, i=6, TickCount=1203823484, Thread=3
'     Task=8, i=7, TickCount=1203823890, Thread=4
'     Task=9, i=8, TickCount=1203824296, Thread=3
'     Task=10, i=9, TickCount=1203824796, Thread=4
'     
'     The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()

public:
 static bool WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, int millisecondsTimeout);

public static bool WaitAll(System.Threading.Tasks.Task[] tasks, int millisecondsTimeout);

static member WaitAll : System.Threading.Tasks.Task[] * int -> bool

Public Shared Function WaitAll (tasks As Task(), millisecondsTimeout As Integer) As Boolean

Parametri

Valori restituiti

true se tutte le istanze hanno completato l'esecuzione Task entro il tempo assegnato; in caso contrario, false.

Eccezioni

public:
 static void WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, System::Threading::CancellationToken cancellationToken);

public static void WaitAll(System.Threading.Tasks.Task[] tasks, System.Threading.CancellationToken cancellationToken);

static member WaitAll : System.Threading.Tasks.Task[] * System.Threading.CancellationToken -> unit

Public Shared Sub WaitAll (tasks As Task(), cancellationToken As CancellationToken)

Parametri

Eccezioni

Commenti

L'argomento cancellationToken viene utilizzato per annullare l'operazione di attesa. L'annullamento delle attività è un'operazione distinta e viene segnalato da come AggregateException indicato in precedenza.

public:
 static bool WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, TimeSpan timeout);

public static bool WaitAll(System.Threading.Tasks.Task[] tasks, TimeSpan timeout);

static member WaitAll : System.Threading.Tasks.Task[] * TimeSpan -> bool

Public Shared Function WaitAll (tasks As Task(), timeout As TimeSpan) As Boolean

Parametri

Valori restituiti

true se tutte le istanze hanno completato l'esecuzione Task entro il tempo assegnato; in caso contrario, false.

Eccezioni

public:
 static bool WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, int millisecondsTimeout, System::Threading::CancellationToken cancellationToken);

public static bool WaitAll(System.Threading.Tasks.Task[] tasks, int millisecondsTimeout, System.Threading.CancellationToken cancellationToken);

static member WaitAll : System.Threading.Tasks.Task[] * int * System.Threading.CancellationToken -> bool

Public Shared Function WaitAll (tasks As Task(), millisecondsTimeout As Integer, cancellationToken As CancellationToken) As Boolean

Parametri

Valori restituiti

true se tutte le istanze hanno completato l'esecuzione Task entro il tempo assegnato; in caso contrario, false.

Eccezioni

Commenti

L'argomento cancellationToken viene utilizzato per annullare l'operazione di attesa. L'annullamento delle attività è un'operazione distinta e viene segnalato dalla AggregateException nota precedente.