fixed broadcast_lsd option. in trunk, redefined it to only broadcast every 8th packet

ChangeLog

@@ -83,6 +83,7 @@
 	  incoming connection
 	* added more detailed instrumentation of the disk I/O thread
 
+	* fixed broadcast_lsd option
 	* fixed udp-socket race condition when using a proxy
 	* end-game mode optimizations
 	* fixed bug in udp_socket causing it to issue two simultaneous async. read operations

docs/manual.rst

@@ -4985,7 +4985,9 @@ be changed individually later using
 if ``broadcast_lsd`` is set to true, the local peer discovery
 (or Local Service Discovery) will not only use IP multicast, but also
 broadcast its messages. This can be useful when running on networks
-that don't support multicast. It's off by default since it's inefficient.
+that don't support multicast. Since broadcast messages might be
+expensive and disruptive on networks, only every 8th announce uses
+broadcast.
 
 ``enable_outgoing_utp``, ``enable_incoming_utp``, ``enable_outgoing_tcp``,
 ``enable_incoming_tcp`` all determines if libtorrent should attempt to make

include/libtorrent/aux_/session_impl.hpp

@@ -327,7 +327,7 @@ namespace libtorrent
 			
 			torrent_handle find_torrent_handle(sha1_hash const& info_hash);
 
-			void announce_lsd(sha1_hash const& ih);
+			void announce_lsd(sha1_hash const& ih, bool broadcast = false);
 
 			void save_state(entry* e, boost::uint32_t flags) const;
 			void load_state(lazy_entry const* e);

include/libtorrent/lsd.hpp

@@ -61,11 +61,9 @@ public:
 
 //	void rebind(address const& listen_interface);
 
-	void announce(sha1_hash const& ih, int listen_port);
+	void announce(sha1_hash const& ih, int listen_port, bool broadcast = false);
 	void close();
 
-	void use_broadcast(bool b);
-
 private:
 
 	void resend_announce(error_code const& e, std::string msg);

include/libtorrent/session_settings.hpp

@@ -226,7 +226,7 @@ namespace libtorrent
 			, strict_end_game_mode(true)
 			, default_peer_upload_rate(0)
 			, default_peer_download_rate(0)
-			, broadcast_lsd(false)
+			, broadcast_lsd(true)
 			, enable_outgoing_utp(true)
 			, enable_incoming_utp(true)
 			, enable_outgoing_tcp(true)

include/libtorrent/torrent.hpp

@@ -1279,6 +1279,10 @@ namespace libtorrent
 		// and set this to false. We only do this once to get
 		// the torrent kick-started
 		bool m_need_connect_boost:1;
+
+		// rotating sequence number for LSD announces sent out.
+		// used to only use IP broadcast for every 8th lsd announce
+		boost::uint8_t m_lsd_seq:3;
 	};
 }
 

src/broadcast_socket.cpp

@@ -252,7 +252,7 @@ namespace libtorrent
 		for (std::list<socket_entry>::iterator i = m_unicast_sockets.begin()
 			, end(m_unicast_sockets.end()); i != end; ++i)
 		{
-			if (i->socket) continue;
+			if (!i->socket) continue;
 			i->socket->set_option(option, ec);
 		}
 	}

src/lsd.cpp

@@ -82,7 +82,7 @@ lsd::lsd(io_service& ios, address const& listen_interface
 
 lsd::~lsd() {}
 
-void lsd::announce(sha1_hash const& ih, int listen_port)
+void lsd::announce(sha1_hash const& ih, int listen_port, bool broadcast)
 {
 	if (m_disabled) return;
 
@@ -98,6 +98,7 @@ void lsd::announce(sha1_hash const& ih, int listen_port)
 
 	m_retry_count = 1;
 	error_code ec;
+	m_socket.enable_ip_broadcast(broadcast);
 	m_socket.send(msg, msg_len, ec);
 	if (ec)
 	{
@@ -117,7 +118,7 @@ void lsd::announce(sha1_hash const& ih, int listen_port)
 #if defined TORRENT_ASIO_DEBUGGING
 	add_outstanding_async("lsd::resend_announce");
 #endif
-	m_broadcast_timer.expires_from_now(milliseconds(250 * m_retry_count), ec);
+	m_broadcast_timer.expires_from_now(seconds(2 * m_retry_count), ec);
 	m_broadcast_timer.async_wait(boost::bind(&lsd::resend_announce, self(), _1
 		, std::string(msg)));
 }
@@ -130,16 +131,17 @@ void lsd::resend_announce(error_code const& e, std::string msg)
 	if (e) return;
 
 	error_code ec;
+	// don't broadcast resends
+	m_socket.enable_ip_broadcast(false);
 	m_socket.send(msg.c_str(), int(msg.size()), ec);
 
 	++m_retry_count;
-	if (m_retry_count >= 5)
-		return;
+	if (m_retry_count >= 3) return;
 
 #if defined TORRENT_ASIO_DEBUGGING
 	add_outstanding_async("lsd::resend_announce");
 #endif
-	m_broadcast_timer.expires_from_now(milliseconds(250 * m_retry_count), ec);
+	m_broadcast_timer.expires_from_now(seconds(2 * m_retry_count), ec);
 	m_broadcast_timer.async_wait(boost::bind(&lsd::resend_announce, self(), _1, msg));
 }
 
@@ -234,8 +236,3 @@ void lsd::close()
 	m_callback.clear();
 }
 
-void lsd::use_broadcast(bool b)
-{
-	m_socket.enable_ip_broadcast(b);
-}
-

src/session_impl.cpp

@@ -1124,9 +1124,6 @@ namespace aux {
 
  		if (m_settings.connection_speed < 0) m_settings.connection_speed = 200;
 
-		if (m_settings.broadcast_lsd && m_lsd)
-			m_lsd->use_broadcast(true);
-
 		update_disk_thread_settings();
 
 		settings = e->dict_find_list("feeds");
@@ -1669,8 +1666,6 @@ namespace aux {
 			m_listen_sockets.clear();
 		}
  		if (m_settings.connection_speed < 0) m_settings.connection_speed = 200;
-		if (m_settings.broadcast_lsd && m_lsd)
-			m_lsd->use_broadcast(true);
  
 		if (update_disk_io_thread)
 			update_disk_thread_settings();
@@ -4171,11 +4166,11 @@ namespace aux {
 		return m_listen_sockets.front().external_port;
 	}
 
-	void session_impl::announce_lsd(sha1_hash const& ih)
+	void session_impl::announce_lsd(sha1_hash const& ih, bool broadcast)
 	{
 		// use internal listen port for local peers
 		if (m_lsd.get())
-			m_lsd->announce(ih, m_listen_interface.port());
+			m_lsd->announce(ih, m_listen_interface.port(), broadcast);
 	}
 
 	void session_impl::on_lsd_peer(tcp::endpoint peer, sha1_hash const& ih)
@@ -4782,8 +4777,6 @@ namespace aux {
 		m_lsd = new lsd(m_io_service
 			, m_listen_interface.address()
 			, boost::bind(&session_impl::on_lsd_peer, this, _1, _2));
-		if (m_settings.broadcast_lsd)
-			m_lsd->use_broadcast(true);
 	}
 	
 	natpmp* session_impl::start_natpmp()

src/torrent.cpp

@@ -403,6 +403,7 @@ namespace libtorrent
 		, m_interface_index(0)
 		, m_graceful_pause_mode(false)
 		, m_need_connect_boost(true)
+		, m_lsd_seq(0)
 	{
 		if (!m_url.empty() && m_uuid.empty()) m_uuid = m_url;
 
@@ -1679,7 +1680,9 @@ namespace libtorrent
 		if (is_paused()) return;
 
 		// announce with the local discovery service
-		m_ses.announce_lsd(m_torrent_file->info_hash());
+		m_ses.announce_lsd(m_torrent_file->info_hash()
+			, m_ses.settings().broadcast_lsd && m_lsd_seq == 0);
+		++m_lsd_seq;
 	}
 
 #ifndef TORRENT_DISABLE_DHT

test/setup_transfer.cpp

@@ -251,14 +251,17 @@ setup_transfer(session* ses1, session* ses2, session* ses3
 	, bool clear_files, bool use_metadata_transfer, bool connect_peers
 	, std::string suffix, int piece_size
 	, boost::intrusive_ptr<torrent_info>* torrent, bool super_seeding
-	, add_torrent_params const* p)
+	, add_torrent_params const* p, bool stop_lsd)
 {
 	assert(ses1);
 	assert(ses2);
 
-	ses1->stop_lsd();
-	ses2->stop_lsd();
-	if (ses3) ses3->stop_lsd();
+	if (stop_lsd)
+	{
+		ses1->stop_lsd();
+		ses2->stop_lsd();
+		if (ses3) ses3->stop_lsd();
+	}
 
 	session_settings sess_set = ses1->settings();
 	if (ses3) sess_set.allow_multiple_connections_per_ip = true;

test/setup_transfer.hpp

@@ -61,7 +61,7 @@ setup_transfer(libtorrent::session* ses1, libtorrent::session* ses2
 	, libtorrent::session* ses3, bool clear_files, bool use_metadata_transfer = true
 	, bool connect = true, std::string suffix = "", int piece_size = 16 * 1024
 	, boost::intrusive_ptr<libtorrent::torrent_info>* torrent = 0, bool super_seeding = false
-	, libtorrent::add_torrent_params const* p = 0);
+	, libtorrent::add_torrent_params const* p = 0, bool stop_lsd = true);
 
 int start_web_server(bool ssl = false, bool chunked = false);
 void stop_web_server();

test/test_lsd.cpp

@@ -58,7 +58,8 @@ void test_lsd()
 	torrent_handle tor2;
 
 	using boost::tuples::ignore;
-	boost::tie(tor1, tor2, ignore) = setup_transfer(&ses1, &ses2, 0, true, false, false, "_lsd");
+	boost::tie(tor1, tor2, ignore) = setup_transfer(&ses1, &ses2, 0, true, false, false, "_lsd"
+		, 16 * 1024, 0, false, 0, false);
 
 	for (int i = 0; i < 30; ++i)
 	{