Use dedicated thread pool

nano/lib/thread_roles.cpp

@@ -190,6 +190,9 @@ std::string nano::thread_role::get_string (nano::thread_role::name role)
 		case nano::thread_role::name::monitor:
 			thread_role_name_string = "Monitor";
 			break;
+		case nano::thread_role::name::http_callbacks:
+			thread_role_name_string = "HTTP callbacks";
+			break;
 		default:
 			debug_assert (false && "nano::thread_role::get_string unhandled thread role");
 	}

nano/lib/thread_roles.hpp

@@ -68,6 +68,7 @@ enum class name
 	vote_router,
 	online_reps,
 	monitor,
+	http_callbacks,
 };
 
 std::string_view to_string (name);

nano/node/node.cpp

@@ -558,6 +558,7 @@ void nano::node::start ()
 	vote_router.start ();
 	online_reps.start ();
 	monitor.start ();
+	http_callbacks.start ();
 
 	add_initial_peers ();
 }
@@ -605,6 +606,7 @@ void nano::node::stop ()
 	message_processor.stop ();
 	network.stop ();
 	monitor.stop ();
+	http_callbacks.stop ();
 
 	bootstrap_workers.stop ();
 	wallet_workers.stop ();
@@ -1075,6 +1077,7 @@ nano::container_info nano::node::container_info () const
 	info.add ("bandwidth", outbound_limiter.container_info ());
 	info.add ("backlog_scan", backlog_scan.container_info ());
 	info.add ("bounded_backlog", backlog.container_info ());
+	info.add ("http_callbacks", http_callbacks.container_info ());
 	return info;
 }
 

nano/node/rpc_callbacks.cpp

@@ -9,7 +9,8 @@ nano::http_callbacks::http_callbacks (nano::node & node_a) :
 	observers{ node_a.observers },
 	ledger{ node_a.ledger },
 	logger{ node_a.logger },
-	stats{ node_a.stats }
+	stats{ node_a.stats },
+	workers{ 1, nano::thread_role::name::http_callbacks }
 {
 	// Only set up callbacks if a callback address is configured
 	if (!config.callback_address.empty ())
@@ -19,6 +20,21 @@ nano::http_callbacks::http_callbacks (nano::node & node_a) :
 	}
 }
 
+void nano::http_callbacks::start ()
+{
+	workers.start ();
+}
+
+void nano::http_callbacks::stop ()
+{
+	workers.stop ();
+}
+
+nano::container_info nano::http_callbacks::container_info () const
+{
+	return workers.container_info ();
+}
+
 void nano::http_callbacks::setup_callbacks ()
 {
 	// Add observer for block confirmations
@@ -36,8 +52,8 @@ void nano::http_callbacks::setup_callbacks ()
 			stats.inc (nano::stat::type::http_callbacks_notified, nano::stat::detail::block_confirmed);
 
 			// Post callback processing to worker thread
-			// Safe to capture 'this' by reference as workers are stopped before node destruction
-			node.workers.post ([this, block_a, account_a, amount_a, is_state_send_a, is_state_epoch_a] () {
+			// Safe to capture 'this' by reference as workers are stopped before this component destruction
+			workers.post ([this, block_a, account_a, amount_a, is_state_send_a, is_state_epoch_a] () {
 				// Construct the callback payload as a property tree
 				boost::property_tree::ptree event;
 				event.add ("account", account_a.to_account ());

nano/node/rpc_callbacks.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <nano/lib/thread_pool.hpp>
 #include <nano/node/fwd.hpp>
 
 namespace nano
@@ -9,6 +10,11 @@ class http_callbacks
 public:
 	explicit http_callbacks (nano::node &);
 
+	void start ();
+	void stop ();
+
+	nano::container_info container_info () const;
+
 private: // Dependencies
 	nano::node_config const & config;
 	nano::node & node;
@@ -20,5 +26,7 @@ private: // Dependencies
 private:
 	void setup_callbacks ();
 	void do_rpc_callback (boost::asio::ip::tcp::resolver::iterator i_a, std::string const &, uint16_t, std::shared_ptr<std::string> const &, std::shared_ptr<std::string> const &, std::shared_ptr<boost::asio::ip::tcp::resolver> const &);
+
+	nano::thread_pool workers;
 };
 }