Редагувати

Поділитися через


ReaderWriterLock.IsReaderLockHeld Property

Definition

Gets a value indicating whether the current thread holds a reader lock.

public:
 property bool IsReaderLockHeld { bool get(); };
public bool IsReaderLockHeld { get; }
member this.IsReaderLockHeld : bool
Public ReadOnly Property IsReaderLockHeld As Boolean

Property Value

true if the current thread holds a reader lock; otherwise, false.

Examples

The following code example demonstrates how to use IsReaderLockHeld to avoid deadlocks.

using namespace System;
using namespace System::Threading;
int main()
{
   ReaderWriterLock^ rwLock = gcnew ReaderWriterLock;
   rwLock->AcquireWriterLock( Timeout::Infinite );
   rwLock->AcquireReaderLock( Timeout::Infinite );
   if ( rwLock->IsReaderLockHeld )
   {
      Console::WriteLine( "Reader lock held." );
      rwLock->ReleaseReaderLock();
   }
   else
   if ( rwLock->IsWriterLockHeld )
   {
      Console::WriteLine( "Writer lock held." );
      rwLock->ReleaseWriterLock();
   }
   else
   {
      Console::WriteLine( "No locks held." );
   }


   if ( rwLock->IsReaderLockHeld )
   {
      Console::WriteLine( "Reader lock held." );
      rwLock->ReleaseReaderLock();
   }
   else
   if ( rwLock->IsWriterLockHeld )
   {
      Console::WriteLine( "Writer lock held." );
      rwLock->ReleaseWriterLock();
   }
   else
   {
      Console::WriteLine( "No locks held." );
   }
}
using System;
using System.Threading;

class LockHeld
{
    static void Main()
    {
        ReaderWriterLock rwLock = new ReaderWriterLock();

        rwLock.AcquireWriterLock(Timeout.Infinite);
        rwLock.AcquireReaderLock(Timeout.Infinite);

        if(rwLock.IsReaderLockHeld)
        {
            Console.WriteLine("Reader lock held.");
            rwLock.ReleaseReaderLock();
        }
        else if(rwLock.IsWriterLockHeld)
        {
            Console.WriteLine("Writer lock held.");
            rwLock.ReleaseWriterLock();
        }
        else
        {
            Console.WriteLine("No locks held.");
        }

        if(rwLock.IsReaderLockHeld)
        {
            Console.WriteLine("Reader lock held.");
            rwLock.ReleaseReaderLock();
        }
        else if(rwLock.IsWriterLockHeld)
        {
            Console.WriteLine("Writer lock held.");
            rwLock.ReleaseWriterLock();
        }
        else
        {
            Console.WriteLine("No locks held.");
        }
    }
}
Imports System.Threading

Public Class LockHeld

    <MTAThread> _
    Shared Sub Main()
    
        Dim rwLock As New ReaderWriterLock()

        rwLock.AcquireWriterLock(Timeout.Infinite)
        rwLock.AcquireReaderLock(Timeout.Infinite)

        If rwLock.IsReaderLockHeld Then
            Console.WriteLine("Reader lock held.")
            rwLock.ReleaseReaderLock()
        Else If rwLock.IsWriterLockHeld Then
            Console.WriteLine("Writer lock held.")
            rwLock.ReleaseWriterLock()
        Else
            Console.WriteLine("No locks held.")
        End If

        If rwLock.IsReaderLockHeld Then
            Console.WriteLine("Reader lock held.")
            rwLock.ReleaseReaderLock()
        Else If rwLock.IsWriterLockHeld Then
            Console.WriteLine("Writer lock held.")
            rwLock.ReleaseWriterLock()
        Else
            Console.WriteLine("No locks held.")
        End If
    
    End Sub
End Class

Applies to

See also