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ReaderWriterLock.ReleaseReaderLock Metoda

  • Reference

Definice

Obor názvů:
System.Threading
Sestavení:
System.Threading.dll
Sestavení:
mscorlib.dll
Sestavení:
netstandard.dll

Sníží počet zámků.

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

Výjimky

ApplicationException

Vlákno nemá žádné zámky čtečky ani zapisovače.

Příklady

Následující příklad kódu ukazuje, jak získat a uvolnit zámek čtenáře a jak zpracovat výjimku vyvolánou při vypršení časového limitu požadavku.

Tento kód je součástí většího příkladu zadaného ReaderWriterLock pro třídu.

// 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

Poznámky

ReleaseReaderLock sníží počet zámků. Když počet dosáhne nuly, zámek se uvolní.

Poznámka

Pokud má vlákno zámek zapisovač, má volání ReleaseReaderLock stejný účinek jako volání ReleaseWriterLock. Pokud vlákno nemá žádné zámky, volání ReleaseReaderLock vyvolá ApplicationException.

Platí pro

Viz také