So now I have gone through the code base of state channel fully (or at least the
update channel part). Based on that I came up with these two diagram. It would be really helpful if someone can validate this. I am also planning to write a blog post on the implementation.
Sequence Diagram of channel update
A ----Tx data---> FSM A FSM A ----rawTx---> A A ----halfSignedTx---> FSM A // FSM A updates its state (half) FSM A ----halfSignedTx---> FSM B // NOISE FSM B --- halfSignedTx---> B B ----fullSignedTx---> FSM B // FSM B updates its state FSM B ----fullSignedTx---> FSM A // NOISE: FSM A updates its state (full)