In this commit, we remove the per channel `sigPool` within the
`lnwallet.LightningChannel` struct. With this change, we ensure that as
the number of channels grows, the number of gouroutines idling in the
sigPool stays constant. It's the case that currently on the daemon, most
channels are likely inactive, with only a hand full actually
consistently carrying out channel updates. As a result, this change
should reduce the amount of idle CPU usage, as we have less active
goroutines in select loops.
In order to make this change, the `SigPool` itself has been publicly
exported such that outside callers can make a `SigPool` and pass it into
newly created channels. Since the sig pool now lives outside the
channel, we were also able to do away with the Stop() method on the
channel all together.
Finally, the server is the sub-system that is currently responsible for
managing the `SigPool` within lnd.
In this commit, we fix a small bug with regards to the persistent peer
connection pruning logic. Before this commit, it'd be the case that we'd
prune a persistent connection to a peer if all links happen to be
inactive. This isn't ideal, as the channels are still open, so we should
always be atttempting to connect to them. We fix this by looking at the
set of channels on-disk instead and prune the persistent connection if
there aren't any.
In this commit, we move the block height dependency from the links in
the switch to the switch itself. This is possible due to a recent change
on the links no longer depending on the block height to update their
commitment fees.
We'll now only have the switch be alerted of new blocks coming in and
links will retrieve the height from it atomically.
In this commit, we address an un accounted for case during the breach
remedy process. If the remote node actually went directly to the second
layer during a channel breach attempt, then we wouldn’t properly be
able to sweep with out justice transaction, as some HTLC inputs may
actually be spent at that point.
In order to address this case, we’ll now catch the transaction
rejection, then check to see which input was spent, promote that to a
second level spend, and repeat as necessary. At the end of this loop,
any inputs which have been spent to the second level will have had the
prevouts and witnesses updated.
In order to perform this transition, we now also store the second level
witness script in the database. This allow us to modify the sign desc
with the proper input value, as well as witness script.
This commit fixes a lingering bug that could at times cause
incompatibilities with other implementations when attempting a
cooperative channel close. Before this commit, we would use a pointer
to the funding txin everywhere. As a result, each time we made a new
state, or verified one, we would modify the sequence field of the main
txin of the commitment transaction. Due to this if we updated the
channel, then went to do a cooperative channel closure, the sequence of
the txin would still be set to the value we used as the state hint.
To remedy this, we now copy the txin each time when making the
commitment transaction, and also the cooperative closure transaction.
This avoids accidentally mutating the txin itself.
Fixes#502.
With the new negotiation policy, we instead just need to ensure that
our fee inches closer to the other party’s with each iteration, and
that it’s within the proper bounds.
This commit adds the fee negotiation procedure performed
on channel shutdown. The current algorithm picks an ideal
a fee based on the FeeEstimator and commit weigth, then
accepts the remote's fee if it is at most 50%-200% away
from the ideal. The fee negotiation procedure is similar
both as sender and receiver of the initial shutdown
message, and this commit also make both sides use the
same code path for handling these messages.
