Amqp.Session.OnBegin C# (CSharp) Method

        internal void OnBegin(ushort remoteChannel, Begin begin)
        {
            lock (this.ThisLock)
            {
                if (this.state == State.BeginSent)
                {
                    this.state = State.Opened;
                }
                else if (this.state == State.EndPipe)
                {
                    this.state = State.EndSent;
                }
                else
                {
                    throw new AmqpException(ErrorCode.IllegalState,
                        Fx.Format(SRAmqp.AmqpIllegalOperationState, "OnBegin", this.state));
                }

                this.outgoingWindow = begin.IncomingWindow;
                this.nextIncomingId = begin.NextOutgoingId;
            }

            if (begin.HandleMax < this.handleMax)
            {
                this.handleMax = begin.HandleMax;
            }

            if (this.onBegin != null)
            {
                this.onBegin(this, begin);
            }
        }

        internal virtual void OnBegin(ushort remoteChannel, Begin begin)
        {
            lock (this.ThisLock)
            {
                if (remoteChannel > this.channelMax)
                {
                    throw new AmqpException(ErrorCode.NotAllowed,
                                            Fx.Format(SRAmqp.AmqpHandleExceeded, this.channelMax + 1));
                }

                Session session = this.GetSession(this.localSessions, begin.RemoteChannel);
                session.OnBegin(remoteChannel, begin);

                int count = this.remoteSessions.Length;
                if (count - 1 < remoteChannel)
                {
                    int       size     = Math.Min(count * 2, this.channelMax + 1);
                    Session[] expanded = new Session[size];
                    Array.Copy(this.remoteSessions, expanded, count);
                    this.remoteSessions = expanded;
                }

                var remoteSession = this.remoteSessions[remoteChannel];
                if (remoteSession != null)
                {
                    throw new AmqpException(ErrorCode.HandleInUse,
                                            Fx.Format(SRAmqp.AmqpHandleInUse, remoteChannel, remoteSession.GetType().Name));
                }

                this.remoteSessions[remoteChannel] = session;
            }
        }