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暂停和中断线程

  • 项目

同步线程活动最常见的方法是阻止和释放线程，或者锁定对象或代码区域。 有关这些锁定和阻止机制的详细信息，请参阅同步基元概述。

也可使线程将自身置于睡眠状态。 当线程被阻止或处于休眠状态时，可以使用 ThreadInterruptedException 使它们脱离等待状态。

Thread.Sleep 方法

调用 Thread.Sleep 方法会导致当前线程立即受阻止，时间为传递到方法的毫秒数或时间间隔，结果是将时间片的剩余部分生成给其他线程。 受阻时间过后，休眠线程继续执行。

一个线程不能调用另一线程上的 Thread.Sleep。 Thread.Sleep 是一种始终让当前线程进入睡眠状态的静态方法。

调用 Thread.Sleep（值为 Timeout.Infinite）可以让线程进入睡眠状态，直到另一个对睡眠线程调用 Thread.Interrupt 方法的线程中断它，或直到 Thread.Abort 方法调用终止它。 下面的示例阐释了这两种中断休眠线程的方法。

using System;
using System.Threading;

public class Example
{
   public static void Main()
   {
      // Interrupt a sleeping thread.
      var sleepingThread = new Thread(Example.SleepIndefinitely);
      sleepingThread.Name = "Sleeping";
      sleepingThread.Start();
      Thread.Sleep(2000);
      sleepingThread.Interrupt();

      Thread.Sleep(1000);

      sleepingThread = new Thread(Example.SleepIndefinitely);
      sleepingThread.Name = "Sleeping2";
      sleepingThread.Start();
      Thread.Sleep(2000);
      sleepingThread.Abort();
   }

   private static void SleepIndefinitely()
   {
      Console.WriteLine("Thread '{0}' about to sleep indefinitely.",
                        Thread.CurrentThread.Name);
      try {
         Thread.Sleep(Timeout.Infinite);
      }
      catch (ThreadInterruptedException) {
         Console.WriteLine("Thread '{0}' awoken.",
                           Thread.CurrentThread.Name);
      }
      catch (ThreadAbortException) {
         Console.WriteLine("Thread '{0}' aborted.",
                           Thread.CurrentThread.Name);
      }
      finally
      {
         Console.WriteLine("Thread '{0}' executing finally block.",
                           Thread.CurrentThread.Name);
      }
      Console.WriteLine("Thread '{0} finishing normal execution.",
                        Thread.CurrentThread.Name);
      Console.WriteLine();
   }
}
// The example displays the following output:
//       Thread 'Sleeping' about to sleep indefinitely.
//       Thread 'Sleeping' awoken.
//       Thread 'Sleeping' executing finally block.
//       Thread 'Sleeping finishing normal execution.
//
//       Thread 'Sleeping2' about to sleep indefinitely.
//       Thread 'Sleeping2' aborted.
//       Thread 'Sleeping2' executing finally block.

Imports System.Threading

Module Example
    Public Sub Main()
        ' Interrupt a sleeping thread. 
        Dim sleepingThread = New Thread(AddressOf Example.SleepIndefinitely)
        sleepingThread.Name = "Sleeping"
        sleepingThread.Start()
        Thread.Sleep(2000)
        sleepingThread.Interrupt()

        Thread.Sleep(1000)

        sleepingThread = New Thread(AddressOf Example.SleepIndefinitely)
        sleepingThread.Name = "Sleeping2"
        sleepingThread.Start()
        Thread.Sleep(2000)
        sleepingThread.Abort()
    End Sub

    Private Sub SleepIndefinitely()
        Console.WriteLine("Thread '{0}' about to sleep indefinitely.",
                          Thread.CurrentThread.Name)
        Try
            Thread.Sleep(Timeout.Infinite)
        Catch ex As ThreadInterruptedException
            Console.WriteLine("Thread '{0}' awoken.",
                              Thread.CurrentThread.Name)
        Catch ex As ThreadAbortException
            Console.WriteLine("Thread '{0}' aborted.",
                              Thread.CurrentThread.Name)
        Finally
            Console.WriteLine("Thread '{0}' executing finally block.",
                              Thread.CurrentThread.Name)
        End Try
        Console.WriteLine("Thread '{0}' finishing normal execution.",
                          Thread.CurrentThread.Name)
        Console.WriteLine()
    End Sub
End Module
' The example displays the following output:
'       Thread 'Sleeping' about to sleep indefinitely.
'       Thread 'Sleeping' awoken.
'       Thread 'Sleeping' executing finally block.
'       Thread 'Sleeping finishing normal execution.
'       
'       Thread 'Sleeping2' about to sleep indefinitely.
'       Thread 'Sleeping2' aborted.
'       Thread 'Sleeping2' executing finally block.

中断线程

可以中断正在等待的线程，具体操作是对受阻止的线程调用 Thread.Interrupt 方法，从而抛出 ThreadInterruptedException，以中断对线程执行的阻止调用。 线程应该捕获 ThreadInterruptedException 并执行任何适于继续工作的操作。 如果线程忽略该异常，则运行时捕获异常，并停止该线程。

注意

如果在调用 Thread.Interrupt 时，未阻止目标线程，则线程在被阻止前将不会中断。 如果线程永远不被阻止，则它可在不被中断的情况下完成。

如果等待是托管的等待，则 Thread.Interrupt 和 Thread.Abort 都会立即唤醒线程。 如果等待是非托管等待（例如，调用 Win32 WaitForSingleObject 函数的平台调用），Thread.Interrupt 和 Thread.Abort 都不能控制线程，直到它返回到或调用托管代码。 在托管代码中，该行为如下：

另请参阅