Opc.Ua.Server.Subscription.Publish C# (CSharp) Method

        public NotificationMessage Publish(
            OperationContext      context, 
            out UInt32Collection  availableSequenceNumbers, 
            out bool              moreNotifications)
        {   
            if (context == null) throw new ArgumentNullException("context");
            
            NotificationMessage message = null;

            lock (m_lock)
            {
                moreNotifications = false;
                availableSequenceNumbers = null;

                // check if expired.
                if (m_expired)
                {
                    return null;
                }

                try
                {
                    // update diagnostics.
                    lock (m_diagnostics)
                    {
                        m_diagnostics.PublishRequestCount++;
                    }

                    message = InnerPublish(context, out availableSequenceNumbers, out moreNotifications);
                    
                    lock (m_diagnostics)
                    {
                        m_diagnostics.UnacknowledgedMessageCount = (uint)availableSequenceNumbers.Count;
                    }
                }
                finally
                {
                    // clear counters on success.
                    if (message != null)
                    {
                        // TraceState(Utils.Format("PUBLISH #{0}", message.SequenceNumber));
                        ResetKeepaliveCount();
                        m_waitingForPublish = moreNotifications;
                        ResetLifetimeCount();
                    }
                }
            }

            return message;
        }