ReaderWriterLock.ReleaseWriterLock Metodo

Definizione

Consente di diminuire il conteggio dei blocchi nel blocco del writer.Decrements the lock count on the writer lock.

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

Eccezioni

Il thread non è responsabile del blocco del writer.The thread does not have the writer lock.

Esempio

Nell'esempio di codice seguente viene illustrato come acquisire e rilasciare un blocco del writer e come gestire l'eccezione generata quando si verifica il timeout di una richiesta.The following code example shows how to acquire and release a writer lock, and how to handle the exception thrown when a request times out.

Questo codice fa parte di un esempio più ampio fornito per la ReaderWriterLock classe.This code is part of a larger example provided for the ReaderWriterLock class.

// 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

Commenti

ReleaseWriterLock decrementa il conteggio dei blocchi del writer.ReleaseWriterLock decrements the writer lock count. Quando il conteggio raggiunge lo zero, viene rilasciato il blocco del writer.When the count reaches zero, the writer lock is released.

Nota

Se un thread ha un blocco reader o nessun blocco, la chiamata a ReleaseWriterLock genera un'eccezione ApplicationException .If a thread has a reader lock, or no locks, calling ReleaseWriterLock throws an ApplicationException.

Si applica a

Vedi anche