Prior to this, we returned PaymentSendFailure from auto retry send payment
methods. This implied that we might return a PartialFailure from them, which
has never been the case. So it makes sense to rework the errors to be a better
fit for the methods.
We're taking error handling in a totally different direction now to make it
more asynchronous, see send_payment_internal for more information.
The new in-`ChannelManager` retries logic does retries as two
separate steps, under two separate locks - first it calculates
the amount that needs to be retried, then it actually sends it.
Because the first step doesn't udpate the amount, a second thread
may come along and calculate the same amount and end up retrying
duplicatively.
Because we generally shouldn't ever be processing retries at the
same time, the fix is trivial - simply take a lock at the top of
the retry loop and hold it until we're done.
In anticipation of the next commit(s) adding threaded tests, we
need to ensure our lockorder checks work fine with multiple
threads. Sadly, currently we have tests in the form
`assert!(mutex.try_lock().is_ok())` to assert that a given mutex is
not locked by the caller to a function.
The fix is rather simple given we already track mutexes locked by a
thread in our `debug_sync` logic - simply replace the check with a
new extension trait which (for test builds) checks the locked state
by only looking at what was locked by the current thread.
We're no longer supporting manual retries since
ChannelManager::send_payment_with_retry can be parameterized by a retry
strategy
This commit also updates all docs related to retry_payment and abandon_payment.
Since these docs frequently overlap with changes in preceding commits where we
start abandoning payments on behalf of the user, all the docs are updated in
one go.
Documentation for CustomMessageHandler wasn't clear how it is related to
PeerManager and contained some grammatical and factual errors. Re-write
the docs and link to the lightning_custom_message crate.
When a peer disconnects but still has channels, the peer's `peer_state`
entry in the `per_peer_state` is not removed by the `peer_disconnected`
function. If the channels with that peer is later closed while still
being disconnected (i.e. force closed), we therefore need to remove the
peer from `peer_state` separately.
To remove the peers separately, we push such peers to a separate HashSet
that holds peers awaiting removal, and remove the peers on a timer to
limit the negative effects on parallelism as much as possible.
Updates multiple instances of the `ChannelManager` docs related to the
previous change that moved the storage of the channels to the
`per_peer_state`. This docs update corrects some grammar errors and
incorrect information, as well as clarifies documentation that was
confusing.
When we apply the new gossip-async-check backpressure on peer
connections, if a peer has never sent us a `channel_announcement`
at all, we really shouldn't delay reading their messages.
This does so by tracking, on a per-peer basis, whether they've sent
us a channel_announcement, and resetting that state whenever we're
not backlogged.
