f Avoid back-to-back locking

Author: tnull

lightning/src/chain/channelmonitor.rs

@@ -1206,6 +1206,20 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
 		self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
 	}
 
+	pub(crate) fn broadcast_latest_holder_commitment_txn_if_unspent<B: Deref, L: Deref>(
+		&self,
+		broadcaster: &B,
+		logger: &L,
+	) where
+		B::Target: BroadcasterInterface,
+		L::Target: Logger,
+	{
+		let mut locked_inner = self.inner.lock().unwrap();
+		if !locked_inner.detected_funding_spend() {
+			locked_inner.broadcast_latest_holder_commitment_txn(broadcaster, logger);
+		}
+	}
+
 	/// Updates a ChannelMonitor on the basis of some new information provided by the Channel
 	/// itself.
 	///
@@ -1236,11 +1250,6 @@ impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
 		self.inner.lock().unwrap().get_funding_txo().clone()
 	}
 
-	/// Gets whether we've seen a confirmed transaction spending the funding output.
-	pub(crate) fn detected_funding_spend(&self) -> bool {
-		self.inner.lock().unwrap().detected_funding_spend()
-	}
-
 	/// Gets a list of txids, with their output scripts (in the order they appear in the
 	/// transaction), which we must learn about spends of via block_connected().
 	pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {

lightning/src/ln/channelmanager.rs

@@ -7208,12 +7208,12 @@ where
 		}
 
 		for (funding_txo, monitor) in args.channel_monitors.iter_mut() {
-			// There's no need to broadcast our commitment transaction if we've seen one
-			// confirmed (even with 1 confirmation) as it'll be rejected as
-			// duplicate/conflicting.
-			if !funding_txo_set.contains(funding_txo) && !monitor.detected_funding_spend() {
+			if !funding_txo_set.contains(funding_txo) {
 				log_info!(args.logger, "Broadcasting latest holder commitment transaction for closed channel {}", log_bytes!(funding_txo.to_channel_id()));
-				monitor.broadcast_latest_holder_commitment_txn(&args.tx_broadcaster, &args.logger);
+				// There's no need to broadcast our commitment transaction if
+				// we've seen one confirmed (even with 1 confirmation) as it'll
+				// be rejected as duplicate/conflicting.
+				monitor.broadcast_latest_holder_commitment_txn_if_unspent(&args.tx_broadcaster, &args.logger);
 			}
 		}