Reduce syncing and shutdown timeouts considerably

Previously, we had to configure enormous syncing timeouts as the BDK
wallet syncing would hold a central mutex that could lead to large parts
of event handling and syncing locking up. Here, we drop the configured
timeouts considerably across the board, since such huge values are
hopefully not required anymore.

Author: tnull

src/chain/electrum.rs

@@ -40,7 +40,7 @@ use std::time::{Duration, Instant};
 
 const BDK_ELECTRUM_CLIENT_BATCH_SIZE: usize = 5;
 const ELECTRUM_CLIENT_NUM_RETRIES: u8 = 3;
-const ELECTRUM_CLIENT_TIMEOUT_SECS: u8 = 20;
+const ELECTRUM_CLIENT_TIMEOUT_SECS: u8 = 10;
 
 pub(crate) struct ElectrumRuntimeClient {
 	electrum_client: Arc<ElectrumClient>,

src/config.rs

@@ -65,10 +65,13 @@ pub(crate) const NODE_ANN_BCAST_INTERVAL: Duration = Duration::from_secs(60 * 60
 pub(crate) const WALLET_SYNC_INTERVAL_MINIMUM_SECS: u64 = 10;
 
 // The timeout after which we abort a wallet syncing operation.
-pub(crate) const BDK_WALLET_SYNC_TIMEOUT_SECS: u64 = 90;
+pub(crate) const BDK_WALLET_SYNC_TIMEOUT_SECS: u64 = 20;
 
 // The timeout after which we abort a wallet syncing operation.
-pub(crate) const LDK_WALLET_SYNC_TIMEOUT_SECS: u64 = 30;
+pub(crate) const LDK_WALLET_SYNC_TIMEOUT_SECS: u64 = 10;
+
+// The timeout after which we give up waiting on LDK's event handler to exit on shutdown.
+pub(crate) const LDK_EVENT_HANDLER_SHUTDOWN_TIMEOUT_SECS: u64 = 30;
 
 // The timeout after which we abort a fee rate cache update operation.
 pub(crate) const FEE_RATE_CACHE_UPDATE_TIMEOUT_SECS: u64 = 5;

src/lib.rs

@@ -126,8 +126,9 @@ pub use builder::NodeBuilder as Builder;
 
 use chain::ChainSource;
 use config::{
-	default_user_config, may_announce_channel, ChannelConfig, Config, NODE_ANN_BCAST_INTERVAL,
-	PEER_RECONNECTION_INTERVAL, RGS_SYNC_INTERVAL,
+	default_user_config, may_announce_channel, ChannelConfig, Config,
+	LDK_EVENT_HANDLER_SHUTDOWN_TIMEOUT_SECS, NODE_ANN_BCAST_INTERVAL, PEER_RECONNECTION_INTERVAL,
+	RGS_SYNC_INTERVAL,
 };
 use connection::ConnectionManager;
 use event::{EventHandler, EventQueue};
@@ -645,6 +646,7 @@ impl Node {
 	pub fn stop(&self) -> Result<(), Error> {
 		let mut runtime_lock = self.runtime.write().unwrap();
 		let _runtime = runtime_lock.take().ok_or(Error::NotRunning)?;
+
 		#[cfg(tokio_unstable)]
 		let metrics_runtime = Arc::clone(&_runtime);
 
@@ -673,14 +675,11 @@ impl Node {
 		let event_handling_stopped_logger = Arc::clone(&self.logger);
 		let mut event_handling_stopped_receiver = self.event_handling_stopped_sender.subscribe();
 
-		// FIXME: For now, we wait up to 100 secs (BDK_WALLET_SYNC_TIMEOUT_SECS + 10) to allow
-		// event handling to exit gracefully even if it was blocked on the BDK wallet syncing. We
-		// should drop this considerably post upgrading to BDK 1.0.
 		let stop_runtime =
 			tokio::runtime::Builder::new_current_thread().enable_time().build().unwrap();
 		let timeout_res = stop_runtime.block_on(async {
 			tokio::time::timeout(
-				Duration::from_secs(100),
+				Duration::from_secs(LDK_EVENT_HANDLER_SHUTDOWN_TIMEOUT_SECS),
 				event_handling_stopped_receiver.changed(),
 			)
 			.await