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ReaderWriterLock.ReleaseWriterLock Metoda

  • Odwołanie

Definicja

Przestrzeń nazw:
System.Threading
Zestaw:
System.Threading.dll
Zestaw:
mscorlib.dll
Zestaw:
netstandard.dll

Dekrementuje liczbę blokad na blokadzie modułu zapisywania.

public:
 void ReleaseWriterLock();
public void ReleaseWriterLock ();
member this.ReleaseWriterLock : unit -> unit
Public Sub ReleaseWriterLock ()

Wyjątki

ApplicationException

Wątek nie ma blokady modułu zapisywania.

Przykłady

W poniższym przykładzie kodu pokazano, jak uzyskać i zwolnić blokadę modułu zapisywania oraz jak obsłużyć wyjątek zgłaszany w przypadku przekroczenia limitu czasu żądania.

Ten kod jest częścią większego przykładu udostępnionego ReaderWriterLock dla klasy.

// The complete code is located in the ReaderWriterLock
// class topic.
using namespace System;
using namespace System::Threading;
public ref class Test
{
public:

   // Declaring the ReaderWriterLock at the class level
   // makes it visible to all threads.
   static ReaderWriterLock^ rwl = gcnew ReaderWriterLock;

   // For this example, the shared resource protected by the
   // ReaderWriterLock is just an integer.
   static int resource = 0;

// The complete code is located in the ReaderWriterLock class topic.
using System;
using System.Threading;

public class Example
{
   static ReaderWriterLock rwl = new ReaderWriterLock();
   // Define the shared resource protected by the ReaderWriterLock.
   static int resource = 0;

' The complete code is located in the ReaderWriterLock class topic.
Imports System.Threading

Public Module Example
   Private rwl As New ReaderWriterLock()
   ' Define the shared resource protected by the ReaderWriterLock.
   Private resource As Integer = 0

// Shows how to request and release the writer lock, and
// how to handle time-outs.
static void WriteToResource( Random^ rnd, int timeOut )
{
   try
   {
      rwl->AcquireWriterLock( timeOut );
      try
      {

         // It is safe for this thread to read or write
         // from the shared resource.
         resource = rnd->Next( 500 );
         Display( String::Format( "writes resource value {0}", resource ) );
         Interlocked::Increment( writes );
      }
      finally
      {

         // Ensure that the lock is released.
         rwl->ReleaseWriterLock();
      }

   }
   catch ( ApplicationException^ )
   {

      // The writer lock request timed out.
      Interlocked::Increment( writerTimeouts );
   }

}

// Request and release the writer lock, and handle time-outs.
static void WriteToResource(Random rnd, int timeOut)
{
   try {
      rwl.AcquireWriterLock(timeOut);
      try {
         // It's safe for this thread to access from the shared resource.
         resource = rnd.Next(500);
         Display("writes resource value " + resource);
         Interlocked.Increment(ref writes);
      }
      finally {
         // Ensure that the lock is released.
         rwl.ReleaseWriterLock();
      }
   }
   catch (ApplicationException) {
      // The writer lock request timed out.
      Interlocked.Increment(ref writerTimeouts);
   }
}

' Request and release the writer lock, and handle time-outs.
Sub WriteToResource(rnd As Random, timeOut As Integer)
   Try
      rwl.AcquireWriterLock(timeOut)
      Try
         ' It's safe for this thread to read or write from the shared resource.
         resource = rnd.Next(500)
         Display("writes resource value " & resource)
         Interlocked.Increment(writes)
      Finally
         ' Ensure that the lock is released.
         rwl.ReleaseWriterLock()
      End Try
   Catch ex As ApplicationException
      ' The writer lock request timed out.
      Interlocked.Increment(writerTimeouts)
   End Try
End Sub

};

}

End Module

Uwagi

ReleaseWriterLock dekrementuje liczbę blokad modułu zapisywania. Gdy liczba osiągnie zero, blokada modułu zapisywania zostanie zwolniona.

Uwaga

Jeśli wątek ma blokadę czytnika lub nie ma blokad, wywołanie wywołania ReleaseWriterLock zgłasza błąd ApplicationException.

Dotyczy

Zobacz też