ReaderWriterLockSlim.ExitWriteLock Method

Definition

Namespace:

System.Threading

Assembly:

System.Threading.dll

Source:

ReaderWriterLockSlim.cs

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

public:
 void ExitWriteLock();

public void ExitWriteLock ();

member this.ExitWriteLock : unit -> unit

Public Sub ExitWriteLock ()

Exceptions

SynchronizationLockException

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

Examples

The following example shows how to use a finally block to execute the ExitWriteLock method, ensuring that the caller exits write mode. The method shown in the example adds a new key/value pair to the synchronized cache. If the key is already in the cache, the exception thrown by the inner Dictionary<TKey,TValue> is allowed to terminate the method. The EnterWriteLock method is used to enter the lock in write 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>();

Private cacheLock As New ReaderWriterLockSlim()
Private innerCache As New Dictionary(Of Integer, String)

public void Add(int key, string value)
{
    cacheLock.EnterWriteLock();
    try
    {
        innerCache.Add(key, value);
    }
    finally
    {
        cacheLock.ExitWriteLock();
    }
}

Public Sub Add(ByVal key As Integer, ByVal value As String)
    cacheLock.EnterWriteLock()
    Try
        innerCache.Add(key, value)
    Finally
        cacheLock.ExitWriteLock()
    End Try
End Sub

Remarks

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 write 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.