Dynamic election timeout

nano/node/election.cpp

@@ -274,7 +274,7 @@ bool nano::election::transition_time (nano::confirmation_solicitor & solicitor_a
 			break;
 	}
 
-	if (!confirmed_locked () && time_to_live () < std::chrono::steady_clock::now () - election_start)
+	if (!confirmed_locked () && has_expired ())
 	{
 		// It is possible the election confirmed while acquiring the mutex
 		// state_change returning true would indicate it
@@ -292,16 +292,24 @@ bool nano::election::transition_time (nano::confirmation_solicitor & solicitor_a
 	return result;
 }
 
-std::chrono::milliseconds nano::election::time_to_live () const
+bool nano::election::has_expired () const
 {
+	const auto now = std::chrono::steady_clock::now ();
+
+	if (now > election_start + max_total_duration)
+	{
+		return true;
+	}
+
 	switch (behavior ())
 	{
 		case election_behavior::manual:
 		case election_behavior::priority:
-			return std::chrono::milliseconds (5 * 60 * 1000);
+			return now > last_vote_received + max_idle_duration_default;
 		case election_behavior::hinted:
+			return now > last_vote_received + max_idle_duration_hinted;
 		case election_behavior::optimistic:
-			return std::chrono::milliseconds (30 * 1000);
+			return now > last_vote_received + max_idle_duration_optimistic;
 	}
 	debug_assert (false);
 	return {};
@@ -491,6 +499,8 @@ nano::vote_code nano::election::vote (nano::account const & rep, uint64_t timest
 	nano::log::arg{ "vote_source", vote_source_a },
 	nano::log::arg{ "weight", weight });
 
+	last_vote_received = std::chrono::steady_clock::now ();
+
 	if (!confirmed_locked ())
 	{
 		confirm_if_quorum (lock);

nano/node/election.hpp

@@ -64,6 +64,13 @@ class election final : public std::enable_shared_from_this<election>
 	std::function<void (std::shared_ptr<nano::block> const &)> confirmation_action;
 	std::function<void (nano::account const &)> live_vote_action;
 
+private:
+	// Election time to live
+	std::chrono::milliseconds max_total_duration = std::chrono::milliseconds (10 * 60 * 1000);
+	std::chrono::milliseconds max_idle_duration_default = std::chrono::milliseconds (30 * 1000);
+	std::chrono::milliseconds max_idle_duration_hinted = std::chrono::milliseconds (10 * 1000);
+	std::chrono::milliseconds max_idle_duration_optimistic = std::chrono::milliseconds (10 * 1000);
+
 private: // State management
 	static unsigned constexpr passive_duration_factor = 5;
 	static unsigned constexpr active_request_count_min = 2;
@@ -76,7 +83,8 @@ class election final : public std::enable_shared_from_this<election>
 	nano::block_hash last_block_hash{ 0 };
 	std::chrono::steady_clock::time_point last_req{};
 	/** The last time vote for this election was generated */
-	std::chrono::steady_clock::time_point last_vote{};
+	std::chrono::steady_clock::time_point last_vote = {};
+	std::chrono::steady_clock::time_point last_vote_received = { std::chrono::steady_clock::now () };
 
 	bool valid_change (nano::election_state, nano::election_state) const;
 	bool state_change (nano::election_state, nano::election_state);
@@ -155,7 +163,7 @@ class election final : public std::enable_shared_from_this<election>
 	void remove_votes (nano::block_hash const &);
 	void remove_block (nano::block_hash const &);
 	bool replace_by_weight (nano::unique_lock<nano::mutex> & lock_a, nano::block_hash const &);
-	std::chrono::milliseconds time_to_live () const;
+	bool has_expired () const;
 	/**
 	 * Calculates minimum time delay between subsequent votes when processing non-final votes
 	 */