Does anyone understand JoinManager?

[Patricia Shanahan <pa...@acm.org>]

In investigating TaskManager requirements, I've got some questions about 
how JoinManager works. Perhaps someone else already understand 
JoinManager well enough to answer, which would save me some code reading 
time.

I'm looking into the issue of retries in the presence of sequence 
numbers. The problem is that a high sequence number task can get through 
while a conflicting low sequence number task is waiting for a retry 
after a failure.

The ProxyRegTask runafter comment claims that only the lowest sequence 
number ProxyRegTask for a given service is guaranteed to start with a 
registration, and therefore be safe to run when there is no service ID. 
Is that correct?

Thanks for any help,

Patricia