Opc.Ua.Server.SubscriptionManager.DeleteSubscription C# (CSharp) Method

        public StatusCode DeleteSubscription(OperationContext context, uint subscriptionId)
        {
            uint publishingIntervalCount = 0;
            int monitoredItemCount = 0;
            Subscription subscription = null;

            lock (m_lock)
            {
                // remove from publish queue.
                if (m_subscriptions.TryGetValue(subscriptionId, out subscription))
                {
                    NodeId sessionId = subscription.SessionId;

                    if (!NodeId.IsNull(sessionId))
                    {
                        // check that the subscrition is the owner.
                        if (context != null && !Object.ReferenceEquals(context.Session, subscription.Session))
                        {
                            throw new ServiceResultException(StatusCodes.BadSessionIdInvalid);
                        }

                        SessionPublishQueue queue = null;

                        if (m_publishQueues.TryGetValue(sessionId, out queue))
                        {
                            queue.Remove(subscription);
                        }
                    }
                }
                
                // check for abandoned subscription.
                if (m_abandonedSubscriptions != null)
                {
                    for (int ii = 0; ii < m_abandonedSubscriptions.Count; ii++)
                    {
                        if (m_abandonedSubscriptions[ii].Id == subscriptionId)
                        {
                            m_abandonedSubscriptions.RemoveAt(ii);
                            Utils.Trace("Server: Abandoned Subscription '{0}' Deleted.", subscriptionId);
                            break;
                        }
                    }
                }

                // remove subscription.
                m_subscriptions.Remove(subscriptionId);
            }

            if (subscription != null)
            {
                monitoredItemCount = subscription.MonitoredItemCount;

                // raise subscription event.
                RaiseSubscriptionEvent(subscription, true);

                // delete subscription.
                subscription.Delete(context);

                // get the count for the diagnostics.
                publishingIntervalCount = GetPublishingIntervalCount();

                lock (m_server.DiagnosticsLock)
                {
                    ServerDiagnosticsSummaryDataType diagnostics = m_server.ServerDiagnostics;
                    diagnostics.CurrentSubscriptionCount--;
                    diagnostics.PublishingIntervalCount = publishingIntervalCount;
                }

                if (context != null && context.Session != null)
                {
                    lock (context.Session.DiagnosticsLock)
                    {
                        SessionDiagnosticsDataType diagnostics = context.Session.SessionDiagnostics;
                        diagnostics.CurrentSubscriptionsCount--;
                        UpdateCurrentMonitoredItemsCount(diagnostics, -monitoredItemCount);
                    }
                }

                return StatusCodes.Good;
            }

            return StatusCodes.BadSubscriptionIdInvalid;
        }