Thread.CurrentThread Propriedade
Definição
Importante
Algumas informações dizem respeito a um produto pré-lançado que pode ser substancialmente modificado antes de ser lançado. A Microsoft não faz garantias, de forma expressa ou implícita, em relação à informação aqui apresentada.
Fica com o tópico que está a correr atualmente.
public:
static property System::Threading::Thread ^ CurrentThread { System::Threading::Thread ^ get(); };public static System.Threading.Thread CurrentThread { get; }static member CurrentThread : System.Threading.ThreadPublic Shared ReadOnly Property CurrentThread As ThreadValor de Propriedade
A que é a representação do thread atualmente Thread em execução.
Exemplos
O exemplo seguinte cria uma tarefa que, por sua vez, gera 20 tarefas filhas. A própria aplicação, assim como cada tarefa, chama o ShowThreadInformation método, que utiliza a CurrentThread propriedade para mostrar informação sobre o thread onde está a correr.
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/
Cada tarefa filha gera 1 milhão de números aleatórios entre 1 e 1 milhão e devolve a sua média. A tarefa pai chama o Task.WaitAll método para garantir que as tarefas filhas foram concluídas antes de mostrar a média devolvida por cada tarefa e calcular a média das médias.
Note que, embora a aplicação corra numa thread em primeiro plano, cada tarefa corre numa thread pool de threads.