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ReaderWriterLock.ReleaseReaderLock Método

  • Referência

Definição

Namespace:
System.Threading
Assembly:
System.Threading.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll

Diminui a contagem de bloqueio.

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

Exceções

ApplicationException

O thread não tem nenhum bloqueio de leitor ou de gravador.

Exemplos

O exemplo de código a seguir mostra como adquirir e liberar um bloqueio de leitor e como lidar com a exceção gerada quando uma solicitação atinge o tempo limite.

Esse código faz parte de um exemplo maior fornecido para a ReaderWriterLock classe.

// 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 a reader lock, and
// how to handle time-outs.
static void ReadFromResource( int timeOut )
{
   try
   {
      rwl->AcquireReaderLock( timeOut );
      try
      {

         // It is safe for this thread to read from
         // the shared resource.
         Display( String::Format( "reads resource value {0}", resource ) );
         Interlocked::Increment( reads );
      }
      finally
      {

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

   }
   catch ( ApplicationException^ )
   {

      // The reader lock request timed out.
      Interlocked::Increment( readerTimeouts );
   }

}

// Request and release a reader lock, and handle time-outs.
static void ReadFromResource(int timeOut)
{
   try {
      rwl.AcquireReaderLock(timeOut);
      try {
         // It is safe for this thread to read from the shared resource.
         Display("reads resource value " + resource);
         Interlocked.Increment(ref reads);
      }
      finally {
         // Ensure that the lock is released.
         rwl.ReleaseReaderLock();
      }
   }
   catch (ApplicationException) {
      // The reader lock request timed out.
      Interlocked.Increment(ref readerTimeouts);
   }
}

' Request and release a reader lock, and handle time-outs.
Sub ReadFromResource(timeOut As Integer)
   Try
      rwl.AcquireReaderLock(timeOut)
      Try
         ' It's safe for this thread to read from the shared resource.
         Display("reads resource value " & resource)
         Interlocked.Increment(reads)
      Finally
         ' Ensure that the lock is released.
         rwl.ReleaseReaderLock()
      End Try
   Catch ex As ApplicationException
      ' The reader lock request timed out.
      Interlocked.Increment(readerTimeouts)
   End Try
End Sub

};

}

End Module

Comentários

ReleaseReaderLock decrements the lock count. Quando a contagem atinge zero, o bloqueio é liberado.

Observação

Se um thread tiver o bloqueio do gravador, a chamada ReleaseReaderLock terá o mesmo efeito que chamar ReleaseWriterLock. Se um thread não tiver bloqueios, a chamada ReleaseReaderLock gerará um ApplicationException.

Aplica-se a

Confira também