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Thread.CurrentThread Vlastnost

Definice

Získá aktuálně spuštěné vlákno.

public:
 static property System::Threading::Thread ^ CurrentThread { System::Threading::Thread ^ get(); };
public static System.Threading.Thread CurrentThread { get; }
static member CurrentThread : System.Threading.Thread
Public Shared ReadOnly Property CurrentThread As Thread

Hodnota vlastnosti

Jedná Thread se o reprezentaci aktuálně spuštěného vlákna.

Příklady

Následující příklad vytvoří úlohu, která následně vytvoří 20 podřízených úkolů. Samotná aplikace, stejně jako každý úkol, volá metodu ShowThreadInformationCurrentThread , která používá vlastnost k zobrazení informací o vlákně, na kterém je spuštěna.

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

public class Example
{
   private static Object lockObj = new Object();
   private static Object rndLock = new Object();

   public static void Main()
   {
      Random rnd = new Random();
      var tasks = new List<Task<Double>>();
      ShowThreadInformation("Application");

      Task<Double> t = Task.Run( () => { ShowThreadInformation("Main Task(Task #" + Task.CurrentId.ToString() + ")");
                                         for (int ctr = 1; ctr <= 20; ctr++)
                                           tasks.Add(Task.Factory.StartNew(
                                              () => { ShowThreadInformation("Task #" + Task.CurrentId.ToString());
                                                      long s = 0;
                                                      for (int n = 0; n <= 999999; n++) {
                                                         lock (rndLock) {
                                                            s += rnd.Next(1, 1000001);
                                                         }
                                                      }
                                                      return s/1000000.0;
                                                    } ));

                                        Task.WaitAll(tasks.ToArray());
                                        Double grandTotal = 0;
                                        Console.WriteLine("Means of each task: ");
                                        foreach (var child in tasks) {
                                           Console.WriteLine("   {0}", child.Result);
                                           grandTotal += child.Result;
                                        }
                                        Console.WriteLine();
                                        return grandTotal / 20;
                                   } );
      Console.WriteLine("Mean of Means: {0}", t.Result);
   }

  private static void ShowThreadInformation(String taskName)
  {
      String msg = null;
      Thread thread = Thread.CurrentThread;
      lock(lockObj) {
         msg = String.Format("{0} thread information\n", taskName) +
               String.Format("   Background: {0}\n", thread.IsBackground) +
               String.Format("   Thread Pool: {0}\n", thread.IsThreadPoolThread) +
               String.Format("   Thread ID: {0}\n", thread.ManagedThreadId);
      }
      Console.WriteLine(msg);
   }
}
// The example displays output like the following:
//       Application thread information
//          Background: False
//          Thread Pool: False
//          Thread ID: 1
//
//       Main Task(Task #1) thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #2 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #4 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #3 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #5 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #7 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #6 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #8 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #9 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #10 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #11 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #12 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #13 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #14 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #15 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #16 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #17 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #18 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #19 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #20 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #21 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Means of each task:
//          500038.740584
//          499810.422703
//          500217.558077
//          499868.534688
//          499295.505866
//          499893.475772
//          499601.454469
//          499828.532502
//          499606.183978
//          499700.276056
//          500415.894952
//          500005.874751
//          500042.237016
//          500092.764753
//          499998.798267
//          499623.054718
//          500018.784823
//          500286.865993
//          500052.68285
//          499764.363303
//
//       Mean of Means: 499908.10030605
open System
open System.Threading
open System.Threading.Tasks

let lockObj = obj ()
let rndLock = obj ()

let showThreadInformation taskName =
    let thread = Thread.CurrentThread

    lock lockObj (fun () ->
        printfn
            $"{taskName} thread information\n   Background: {thread.IsBackground}\n   Thread Pool: {thread.IsThreadPoolThread}\n   Thread ID: {thread.ManagedThreadId}\n")

let rnd = Random()
showThreadInformation "Application"

let t =
    Task.Run(fun () ->
        showThreadInformation $"Main Task(Task #{Task.CurrentId})"

        let tasks =
            [| for _ = 1 to 20 do
                   Task.Factory.StartNew(fun () ->
                       showThreadInformation $"Task #{Task.CurrentId}"
                       let mutable s = 0L

                       for n = 0 to 999999 do
                           lock rndLock (fun () -> s <- s + (rnd.Next(1, 1000001) |> int64))

                       float s / 1000000.) |]

        Task.WaitAll(box tasks :?> Task[])
        let mutable grandTotal = 0.
        printfn "Means of each task: "

        for child in tasks do
            printfn $"   {child.Result}"
            grandTotal <- grandTotal + child.Result

        printfn ""
        grandTotal / 20.)

printfn $"Mean of Means: {t.Result}"

// The example displays output like the following:
//       Application thread information
//          Background: False
//          Thread Pool: False
//          Thread ID: 1
//
//       Main Task(Task #1) thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #2 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #4 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #3 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #5 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #7 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #6 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #8 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #9 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #10 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #11 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #12 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #13 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #14 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #15 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #16 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #17 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #18 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #19 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #20 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #21 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Means of each task:
//          500038.740584
//          499810.422703
//          500217.558077
//          499868.534688
//          499295.505866
//          499893.475772
//          499601.454469
//          499828.532502
//          499606.183978
//          499700.276056
//          500415.894952
//          500005.874751
//          500042.237016
//          500092.764753
//          499998.798267
//          499623.054718
//          500018.784823
//          500286.865993
//          500052.68285
//          499764.363303
//
//       Mean of Means: 499908.10030605
Imports System.Collections.Generic
Imports System.Threading
Imports System.Threading.Tasks

Module Example
   Private lockObj As New Object()
   Private rndLock As New Object()
   
   Public Sub Main()
      Dim rnd As New Random()
      Dim tasks As New List(Of Task)
      ShowThreadInformation("Application")

      Dim t As Task(Of Double) = Task.Run( Function()
                                        ShowThreadInformation("Main Task(Task #" + Task.CurrentId.ToString() + ")")
                                        For ctr As Integer = 1 To 20
                                           tasks.Add(Task.Factory.StartNew( Function()
                                                                     ShowThreadInformation("Task #" + Task.CurrentId.ToString())
                                                                     Dim s As Long = 0
                                                                     For n As Integer = 0 To 999999
                                                                        SyncLock rndLock
                                                                           s += rnd.Next(1, 1000001)
                                                                        End SyncLock
                                                                     Next
                                                                     Return s/1000000
                                                                  End Function))
                                        Next

                                        Task.WaitAll(tasks.ToArray())
                                        Dim grandTotal As Double
                                        Console.WriteLine("Means of each task: ")
                                        For Each t In tasks
                                           Console.WriteLine("   {0}", t.Result)
                                           grandTotal += t.Result
                                        Next
                                        Console.WriteLine()
                                        Return grandTotal / 20
                                   End Function )
      Console.WriteLine("Mean of Means: {0}", t.Result)
   End Sub
   
   Private Sub ShowThreadInformation(taskName As String)
      Dim msg As String = Nothing
      Dim thread As Thread = Thread.CurrentThread
      SyncLock lockObj
         msg = String.Format("{0} thread information", taskName) + vbCrLf +
               String.Format("   Background: {0}", thread.IsBackground) + vbCrLf +
               String.Format("   Thread Pool: {0}", thread.IsThreadPoolThread) + vbCrLf +
               String.Format("   Thread ID: {0}", thread.ManagedThreadId) + vbCrLf
      End SyncLock
      Console.WriteLine(msg)
   End Sub
End Module
' The example displays output like the following:
'       Application thread information
'          Background: False
'          Thread Pool: False
'          Thread ID: 1
'
'       Main Task(Task #1) thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 3
'
'       Task #2 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 4
'
'       Task #4 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 10
'
'       Task #3 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 9
'
'       Task #5 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 3
'
'       Task #7 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 5
'
'       Task #6 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 7
'
'       Task #8 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 6
'
'       Task #9 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 8
'
'       Task #10 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 9
'
'       Task #11 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 10
'
'       Task #12 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 6
'
'       Task #13 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 4
'
'       Task #14 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 3
'
'       Task #15 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 7
'
'       Task #16 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 5
'
'       Task #17 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 8
'
'       Task #18 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 9
'
'       Task #19 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 10
'
'       Task #20 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 4
'
'       Task #21 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 7
'
'       Means of each task:
'          500038.740584
'          499810.422703
'          500217.558077
'          499868.534688
'          499295.505866
'          499893.475772
'          499601.454469
'          499828.532502
'          499606.183978
'          499700.276056
'          500415.894952
'          500005.874751
'          500042.237016
'          500092.764753
'          499998.798267
'          499623.054718
'          500018.784823
'          500286.865993
'          500052.68285
'          499764.363303
'
'       Mean of Means: 499908.10030605/

Každý podřízený úkol vygeneruje 1 milion náhodných čísel mezi 1 a 1 milionem a vrátí jejich střední hodnotu. Nadřazená úloha volá metodu Task.WaitAll , aby se zajistilo, že podřízené úkoly byly dokončeny před zobrazením průměru vráceného jednotlivými úkoly a výpočtem průměru průměrů.

Všimněte si, že zatímco aplikace běží ve vlákně na popředí, každý úkol běží ve vlákně fondu vláken.

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