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

        public virtual void SessionClosing(OperationContext context, NodeId sessionId, bool deleteSubscriptions)
        {
            // close the publish queue for the session.
            SessionPublishQueue queue = null;
            IList<Subscription> subscriptionsToDelete = null;

            lock (m_lock)
            {
                if (m_publishQueues.TryGetValue(sessionId, out queue))
                {
                    m_publishQueues.Remove(sessionId);
                    subscriptionsToDelete = queue.Close();

                    // remove the subscriptions.
                    if (deleteSubscriptions && subscriptionsToDelete != null)
                    {
                        for (int ii = 0; ii < subscriptionsToDelete.Count; ii++)
                        {
                            m_subscriptions.Remove(subscriptionsToDelete[ii].Id);
                        }
                    }
                }
            }

            //remove the expired subscription status change notifications for this session
            lock (m_statusMessages)
            {
                Queue<StatusMessage> statusQueue = null;
                if (m_statusMessages.TryGetValue(sessionId, out statusQueue))
                {
                    m_statusMessages.Remove(sessionId);
                }
            }

            // process all subscriptions in the queue.
            if (subscriptionsToDelete != null)
            {
                for (int ii = 0; ii < subscriptionsToDelete.Count; ii++)
                {
                    Subscription subscription = subscriptionsToDelete[ii];

                    // delete the subscription.
                    if (deleteSubscriptions)
                    {
                        // raise subscription event.
                        RaiseSubscriptionEvent(subscription, true);

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

                    // mark the subscriptions as abandoned.
                    else
                    {
                        lock (m_lock)
                        {
                            if (m_abandonedSubscriptions == null)
                            {
                                m_abandonedSubscriptions = new List<Subscription>();
                            }

                            m_abandonedSubscriptions.Add(subscription);
                            Utils.Trace("Server: Subscription '{0}' Abandoned.", subscription.Id);
                        }
                    }
                }
            }
        }