Sub ReleaseLock() 

void ReleaseLock()

void DoSomeThreadSafeWork(IWorkbookSet workbookSet)
        {
            // Interrupt background calculation if necessary and acquire an
            // exclusive lock on the workbook set.
            workbookSet.GetLock();
 
            try {
                // Do some work...
            }
            finally {
                // Release the lock on the workbook set and start background
                // calculation if appropriate.
                workbookSet.ReleaseLock();
            }
        }

Sub DoSomeThreadSafeWork(ByVal workbookSet As IWorkbookSet)
            ' Interrupt background calculation if necessary and acquire an 
            ' exclusive lock on the workbook set. 
            workbookSet.GetLock()
 
            Try
                ' Do some work... 
            Finally
                ' Release the lock on the workbook set and start background 
                ' calculation if appropriate. 
                workbookSet.ReleaseLock()
            End Try
        End Sub 'DoSomeThreadSafeWork