System.Net.WebSockets.WebSocketBase.OnKeepAlive C# (CSharp) Method

        private async static void OnKeepAlive(object sender)
        {
            Debug.Assert(sender != null, "'sender' MUST NOT be NULL.");
            Debug.Assert((sender as WebSocketBase) != null, "'sender as WebSocketBase' MUST NOT be NULL.");

            WebSocketBase thisPtr = sender as WebSocketBase;
            bool lockTaken = false;

            if (NetEventSource.IsEnabled)
            {
                NetEventSource.Enter(thisPtr);
            }

            CancellationToken linkedCancellationToken = CancellationToken.None;
            try
            {
                Monitor.Enter(thisPtr.SessionHandle, ref lockTaken);

                if (thisPtr._isDisposed ||
                    thisPtr._state != WebSocketState.Open ||
                    thisPtr._closeOutputTask != null)
                {
                    return;
                }

                if (thisPtr._keepAliveTracker.ShouldSendKeepAlive())
                {
                    bool ownsCancellationTokenSource = false;
                    try
                    {
                        ownsCancellationTokenSource = thisPtr._sendOutstandingOperationHelper.TryStartOperation(CancellationToken.None, out linkedCancellationToken);
                        if (ownsCancellationTokenSource)
                        {
                            thisPtr.EnsureKeepAliveOperation();
                            thisPtr._keepAliveTask = thisPtr._keepAliveOperation.Process(null, linkedCancellationToken);
                            ReleaseLock(thisPtr.SessionHandle, ref lockTaken);
                            await thisPtr._keepAliveTask.SuppressContextFlow();
                        }
                    }
                    finally
                    {
                        if (!lockTaken)
                        {
                            Monitor.Enter(thisPtr.SessionHandle, ref lockTaken);
                        }
                        thisPtr._sendOutstandingOperationHelper.CompleteOperation(ownsCancellationTokenSource);
                        thisPtr._keepAliveTask = null;
                    }

                    thisPtr._keepAliveTracker.ResetTimer();
                }
            }
            catch (Exception exception)
            {
                try
                {
                    thisPtr.ThrowIfConvertibleException(nameof(OnKeepAlive),
                        exception,
                        CancellationToken.None,
                        linkedCancellationToken.IsCancellationRequested);
                    throw;
                }
                catch (Exception backgroundException)
                {
                    thisPtr.OnBackgroundTaskException(backgroundException);
                }
            }
            finally
            {
                ReleaseLock(thisPtr.SessionHandle, ref lockTaken);

                if (NetEventSource.IsEnabled)
                {
                    NetEventSource.Exit(thisPtr);
                }
            }
        }