+ /// Check the holding cell in each channel and free any pending HTLCs in them if possible.
+ /// This should only apply to HTLCs which were added to the holding cell because we were
+ /// waiting on a monitor update to finish. In that case, we don't want to free the holding cell
+ /// directly in `channel_monitor_updated` as it may introduce deadlocks calling back into user
+ /// code to inform them of a channel monitor update.
+ fn check_free_holding_cells(&self) {
+ let mut failed_htlcs = Vec::new();
+ let mut handle_errors = Vec::new();
+ {
+ let mut channel_state_lock = self.channel_state.lock().unwrap();
+ let channel_state = &mut *channel_state_lock;
+ let by_id = &mut channel_state.by_id;
+ let short_to_id = &mut channel_state.short_to_id;
+ let pending_msg_events = &mut channel_state.pending_msg_events;
+
+ by_id.retain(|channel_id, chan| {
+ match chan.maybe_free_holding_cell_htlcs(&self.logger) {
+ Ok((None, ref htlcs)) if htlcs.is_empty() => true,
+ Ok((commitment_opt, holding_cell_failed_htlcs)) => {
+ failed_htlcs.push((holding_cell_failed_htlcs, *channel_id));
+ if let Some((commitment_update, monitor_update)) = commitment_opt {
+ if let Err(e) = self.chain_monitor.update_channel(chan.get_funding_txo().unwrap(), monitor_update) {
+ let (res, close_channel) = handle_monitor_err!(self, e, short_to_id, chan, RAACommitmentOrder::CommitmentFirst, false, true, Vec::new(), Vec::new(), channel_id);
+ handle_errors.push((chan.get_counterparty_node_id(), res));
+ if close_channel { return false; }
+ } else {
+ pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
+ node_id: chan.get_counterparty_node_id(),
+ updates: commitment_update,
+ });
+ }
+ }
+ true
+ },
+ Err(e) => {
+ let (close_channel, res) = convert_chan_err!(self, e, short_to_id, chan, channel_id);
+ handle_errors.push((chan.get_counterparty_node_id(), Err(res)));
+ !close_channel
+ }
+ }
+ });
+ }
+ for (failures, channel_id) in failed_htlcs.drain(..) {
+ self.fail_holding_cell_htlcs(failures, channel_id);
+ }
+
+ for (counterparty_node_id, err) in handle_errors.drain(..) {
+ let _ = handle_error!(self, err, counterparty_node_id);
+ }
+ }
+