ReaderWriterLock.ReleaseReaderLock Metoda

Definicja

Przestrzeń nazw:

System.Threading

Zestaw:

System.Threading.dll

Źródło:

ReaderWriterLock.cs

Dekrementuje liczbę blokad.

public:
 void ReleaseReaderLock();

public void ReleaseReaderLock ();

member this.ReleaseReaderLock : unit -> unit

Public Sub ReleaseReaderLock ()

Wyjątki

ApplicationException

Wątek nie ma żadnych blokad czytnika ani zapisywania.

Przykłady

Poniższy przykład kodu pokazuje, jak uzyskać i zwolnić blokadę czytnika oraz jak obsługiwać wyjątek zgłaszany po przekroczeniu 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 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

Uwagi

ReleaseReaderLock dekrementuje liczbę blokad. Gdy liczba osiągnie zero, blokada zostanie zwolniona.

Uwaga

Jeśli wątek ma blokadę składnika zapisywania, wywołanie ReleaseReaderLock ma taki sam efekt jak wywołanie metody ReleaseWriterLock. Jeśli wątek nie ma blokad, wywołanie ReleaseReaderLock metody zgłasza błąd ApplicationException.

Zobacz też

• Zarządzane wątkowanie
• Readerwriterlock