Make confirm_back () non-recursive (#1754)

nanocurrency · Feb 20, 2019 · 42bc837 · 42bc837
1 parent c0356a4
commit 42bc837
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Showing 2 changed files with 19 additions and 13 deletions.
diff --git a/nano/node/node.cpp b/nano/node/node.cpp
@@ -3036,9 +3036,8 @@ void nano::election::compute_rep_votes (nano::transaction const & transaction_a)
 	}
 }
 
-void nano::election::confirm_once (nano::transaction const & transaction_a, uint8_t & depth_a)
+void nano::election::confirm_once (nano::transaction const & transaction_a, bool confirmed_back)
 {
-	depth_a++;
 	if (!confirmed.exchange (true))
 	{
 		status.election_end = std::chrono::duration_cast<std::chrono::milliseconds> (std::chrono::system_clock::now ().time_since_epoch ());
@@ -3050,22 +3049,30 @@ void nano::election::confirm_once (nano::transaction const & transaction_a, uint
 			node_l->process_confirmed (winner_l);
 			confirmation_action_l (winner_l);
 		});
-		confirm_back (transaction_a, depth_a);
+		if (!confirmed_back)
+		{
+			confirm_back (transaction_a);
+		}
 	}
 }
 
-void nano::election::confirm_back (nano::transaction const & transaction_a, uint8_t & depth_a)
+void nano::election::confirm_back (nano::transaction const & transaction_a)
 {
-	std::vector<nano::block_hash> hashes = { status.winner->previous (), status.winner->source (), status.winner->link () };
-	for (auto & hash : hashes)
+	std::deque<nano::block_hash> hashes = { status.winner->previous (), status.winner->source (), status.winner->link () };
+	while (!hashes.empty ())
 	{
-		// Depth is limited to 200
-		if (!hash.is_zero () && !node.ledger.is_epoch_link (hash) && depth_a < 200)
+		auto hash (hashes.front ());
+		hashes.pop_front ();
+		if (!hash.is_zero () && !node.ledger.is_epoch_link (hash))
 		{
 			auto existing (node.active.blocks.find (hash));
 			if (existing != node.active.blocks.end () && !existing->second->confirmed && !existing->second->stopped && existing->second->blocks.size () == 1)
 			{
-				existing->second->confirm_once (transaction_a, depth_a);
+				release_assert (existing->second->status.winner->hash () == hash);
+				existing->second->confirm_once (transaction_a, true); // Avoid recursive actions
+				hashes.push_back (existing->second->status.winner->previous ());
+				hashes.push_back (existing->second->status.winner->source ());
+				hashes.push_back (existing->second->status.winner->link ());
 			}
 		}
 	}
@@ -3135,8 +3142,7 @@ void nano::election::confirm_if_quorum (nano::transaction const & transaction_a)
 		{
 			log_votes (tally_l);
 		}
-		uint8_t depth (0);
-		confirm_once (transaction_a, depth);
+		confirm_once (transaction_a);
 	}
 }
 

diff --git a/nano/node/node.hpp b/nano/node/node.hpp
@@ -64,8 +64,8 @@ class election_vote_result
 class election : public std::enable_shared_from_this<nano::election>
 {
 	std::function<void(std::shared_ptr<nano::block>)> confirmation_action;
-	void confirm_once (nano::transaction const &, uint8_t &);
-	void confirm_back (nano::transaction const &, uint8_t &);
+	void confirm_once (nano::transaction const &, bool = false);
+	void confirm_back (nano::transaction const &);
 
 public:
 	election (nano::node &, std::shared_ptr<nano::block>, std::function<void(std::shared_ptr<nano::block>)> const &);