Graceful shutdown

nano/node/confirming_set.cpp

@@ -133,10 +133,11 @@ void nano::confirming_set::run_batch (std::unique_lock<std::mutex> & lock)
 		notification.already_cemented.swap (already);
 
 		std::unique_lock lock{ mutex };
+
 		while (notification_workers.num_queued_tasks () >= config.max_queued_notifications)
 		{
 			stats.inc (nano::stat::type::confirming_set, nano::stat::detail::cooldown);
-			condition.wait_for (lock, 100ms, [this] { return stopped; });
+			condition.wait_for (lock, 100ms, [this] { return stopped.load (); });
 			if (stopped)
 			{
 				return;
@@ -168,11 +169,17 @@ void nano::confirming_set::run_batch (std::unique_lock<std::mutex> & lock)
 			{
 				transaction.refresh_if_needed ();
 
-				stats.inc (nano::stat::type::confirming_set, nano::stat::detail::cementing);
+				// Cementing deep dependency chains might take a long time, allow for graceful shutdown, ignore notifications
+				if (stopped)
+				{
+					break;
+				}
 
 				// Issue notifications here, so that `cemented` set is not too large before we add more blocks
 				notify_maybe (transaction);
 
+				stats.inc (nano::stat::type::confirming_set, nano::stat::detail::cementing);
+
 				auto added = ledger.confirm (transaction, hash, config.max_blocks);
 				if (!added.empty ())
 				{

nano/node/confirming_set.hpp

@@ -75,7 +75,7 @@ class confirming_set final
 
 	nano::thread_pool notification_workers;
 
-	bool stopped{ false };
+	std::atomic<bool> stopped{ false };
 	mutable std::mutex mutex;
 	std::condition_variable condition;
 	std::thread thread;