upgrade priority elections - allow immediate votes

nano/node/active_elections.cpp

@@ -435,6 +435,19 @@ nano::election_insertion_result nano::active_elections::insert (std::shared_ptr<
 	else
 	{
 		result.election = existing->election;
+
+		// Upgrade to priority election to enable immediate vote broadcasting.
+		auto previous_behavior = result.election->behavior ();
+		if (election_behavior_a == nano::election_behavior::priority && result.election->behavior () != nano::election_behavior::priority)
+		{
+			count_by_behavior[result.election->behavior ()]--;
+			count_by_behavior[election_behavior_a]++;
+			result.election->transition_priority ();
+
+			node.logger.debug (nano::log::type::active_elections, "Upgraded election behavior from {} to priority for block: {}",
+			to_string (previous_behavior),
+			hash.to_string ());
+		}
 	}
 
 	lock.unlock ();

nano/node/election.cpp

@@ -183,6 +183,13 @@ void nano::election::transition_active ()
 	state_change (nano::election_state::passive, nano::election_state::active);
 }
 
+void nano::election::transition_priority ()
+{
+	nano::lock_guard<nano::mutex> guard{ mutex };
+	behavior_m = nano::election_behavior::priority;
+	last_vote = std::chrono::steady_clock::time_point{}; // allow new outgoing votes immediately
+}
+
 void nano::election::cancel ()
 {
 	nano::lock_guard<nano::mutex> guard{ mutex };
@@ -849,4 +856,4 @@ std::string_view nano::to_string (nano::election_state state)
 nano::stat::detail nano::to_stat_detail (nano::election_state state)
 {
 	return nano::enum_util::cast<nano::stat::detail> (state);
-}
+}

nano/node/election.hpp

@@ -87,6 +87,7 @@ class election final : public std::enable_shared_from_this<election>
 public: // State transitions
 	bool transition_time (nano::confirmation_solicitor &);
 	void transition_active ();
+	void transition_priority ();
 	void cancel ();
 
 public: // Status
@@ -180,7 +181,7 @@ class election final : public std::enable_shared_from_this<election>
 	mutable nano::uint128_t final_weight{ 0 };
 	mutable std::unordered_map<nano::block_hash, nano::uint128_t> last_tally;
 
-	nano::election_behavior const behavior_m;
+	nano::election_behavior behavior_m;
 	std::chrono::steady_clock::time_point const election_start{ std::chrono::steady_clock::now () };
 
 	mutable nano::mutex mutex;