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ReaderWriterLockSlim.ExitReadLock Method

Reduces the recursion count for read mode, and exits read mode if the resulting count is 0 (zero).

Namespace:  System.Threading
Assembly:  System.Core (in System.Core.dll)

public void ExitReadLock()

ExceptionCondition
SynchronizationLockException

The current thread has not entered the lock in read mode.

This method is not sensitive to recursion order. For example, if a thread enters a lock in upgradeable mode and then enters the lock in read mode, the order in which the thread exits the two modes does not matter. If a lock allows recursion, a thread can enter the lock in write mode and then enter it recursively in read mode; the order in which the thread exits read mode and write mode does not matter.

Exiting the lock might signal other waiting threads.

The following example shows how to use a finally block to execute the ExitReadLock method, ensuring that the caller exits read mode. The method shown in the example retrieves the value associated with a key. If the key is not found, the exception thrown by the inner Dictionary<TKey, TValue> is allowed to terminate the method. The EnterReadLock method is used to enter read mode.

This code is part of a larger example provided for the ReaderWriterLockSlim class.


private ReaderWriterLockSlim cacheLock = new ReaderWriterLockSlim();
private Dictionary<int, string> innerCache = new Dictionary<int, string>();


...


public string Read(int key)
{
    cacheLock.EnterReadLock();
    try
    {
        return innerCache[key];
    }
    finally
    {
        cacheLock.ExitReadLock();
    }
}


.NET Framework

Supported in: 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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