System.Runtime.Remoting.Lifetime.Lease.SponsorCallback C# (CSharp) Method

        internal void SponsorCallback(IAsyncResult iar)
        {
            BCLDebug.Trace("REMOTE","Lease ",id," SponsorCallback IAsyncResult ",iar," state ",((Enum)state).ToString());
            if (state == LeaseState.Expired)
            {
                return;
            }

            int thisThread = Thread.CurrentThread.GetHashCode();
            if (thisThread == sponsorCallThread)
            {
                WaitCallback threadFunc = new WaitCallback(this.SponsorCallback);
                ThreadPool.QueueUserWorkItem(threadFunc, iar);
                return;
            }

            AsyncResult asyncResult = (AsyncResult)iar;
            AsyncRenewal ar = (AsyncRenewal)asyncResult.AsyncDelegate;
            ISponsor sponsor = (ISponsor)ar.Target;
            SponsorStateInfo sponsorStateInfo = null;
            if (iar.IsCompleted)
            {
                // Sponsor came back with renewal
                BCLDebug.Trace("REMOTE","Lease ",id," SponsorCallback sponsor completed");
                bool exceptionOccurred = false;
                TimeSpan renewalTime = TimeSpan.Zero;
                try
                {
                    renewalTime = (TimeSpan)ar.EndInvoke(iar);
                }catch(Exception)
                {
                    // Sponsor not avaiable
                    exceptionOccurred = true;
                }
                if (exceptionOccurred)
                {
                    BCLDebug.Trace("REMOTE","Lease ",id," SponsorCallback Sponsor Exception ");
                    Unregister(sponsor);
                    ProcessNextSponsor();
                }
                else
                {
                    Object sponsorId = GetSponsorId(sponsor);
                    lock(sponsorTable)
                    {
                        if (sponsorTable.ContainsKey(sponsorId))
                        {
                            sponsorStateInfo = (SponsorStateInfo)sponsorTable[sponsorId];
                            sponsorStateInfo.sponsorState = SponsorState.Completed;
                            sponsorStateInfo.renewalTime = renewalTime;
                        }
                        else
                        {
                            // Sponsor was deleted, possibly from a sponsor time out
                        }
                    }

                    if (sponsorStateInfo == null)
                    {
                        // Sponsor was deleted
                        ProcessNextSponsor();
                    }
                    else if (sponsorStateInfo.renewalTime == TimeSpan.Zero)
                    {
                        BCLDebug.Trace("REMOTE","Lease ",id," SponsorCallback sponsor did not renew ");                                            
                        Unregister(sponsor);
                        ProcessNextSponsor();
                    }
                    else
                        Renew(sponsorStateInfo.renewalTime);
                }
            }
            else
            {
                // Sponsor timed out
                // Note time outs should be handled by the LeaseManager
                BCLDebug.Trace("REMOTE","Lease ",id," SponsorCallback sponsor did not complete, timed out");
                Unregister(sponsor);                    
                ProcessNextSponsor();
            }
        }