Merge pull request #299 from arvidn/fix-torrent-invariants

torrent invariant failure

include/libtorrent/performance_counters.hpp

@@ -319,8 +319,7 @@ namespace libtorrent
 		{
 			num_checking_torrents = num_stats_counters,
 			num_stopped_torrents,
-			// upload_only means finished
-			num_upload_only_torrents,
+			num_upload_only_torrents, // upload_only means finished
 			num_downloading_torrents,
 			num_seeding_torrents,
 			num_queued_seeding_torrents,

simulation/swarm_suite.cpp

@@ -53,9 +53,17 @@ struct test_swarm_config : swarm_config
 		, m_resumed_once(false)
 	{}
 
+	virtual bool tick(int t) override
+	{
+		return (m_flags & early_shutdown) ? t >= 1 : t > 200;
+	}
+
 	virtual void on_exit(std::vector<torrent_handle> const& torrents) override
 	{
-		swarm_config::on_exit(torrents);
+		if ((m_flags & early_shutdown) == 0)
+		{
+			swarm_config::on_exit(torrents);
+		}
 
 		// if we stopped and started again, we loose some time and need a bit
 		// more slack for completion

simulation/swarm_suite.hpp

@@ -44,7 +44,8 @@ enum test_flags_t
 	stop_start_download = 128,
 	stop_start_seed = 256,
 	graceful_pause = 1024,
-	add_extra_peers = 2048
+	add_extra_peers = 2048,
+	early_shutdown = 4096
 };
 
 void EXPORT simulate_swarm(int flags = 0);

simulation/test_swarm.cpp

@@ -80,3 +80,8 @@ TORRENT_TEST(explicit_cache)
 	simulate_swarm(suggest_read_cache | explicit_cache);
 }
 
+TORRENT_TEST(shutdown)
+{
+	simulate_swarm(early_shutdown);
+}
+

src/session_impl.cpp

@@ -1123,11 +1123,17 @@ namespace aux {
 		m_ssl_udp_socket.close();
 #endif
 
-		m_undead_peers.clear();
-
-		// give all the sockets an opportunity to actually have their handlers
-		// called and cancelled before we continue the shutdown
-		m_io_service.post(boost::bind(&session_impl::abort_stage2, this));
+		// we need to give all the sockets an opportunity to actually have their handlers
+		// called and cancelled before we continue the shutdown. This is a bit
+		// complicated, if there are no "undead" peers, it's safe tor resume the
+		// shutdown, but if there are, we have to wait for them to be cleared out
+		// first. In session_impl::on_tick() we check them periodically. If we're
+		// shutting down and we remove the last one, we'll initiate
+		// shutdown_stage2 from there.
+		if (m_undead_peers.empty())
+		{
+			m_io_service.post(boost::bind(&session_impl::abort_stage2, this));
+		}
 	}
 
 	void session_impl::abort_stage2()
@@ -2932,6 +2938,25 @@ retry:
 		aux::update_time_now();
 		time_point now = aux::time_now();
 
+		// remove undead peers that only have this list as their reference keeping them alive
+		if (!m_undead_peers.empty())
+		{
+			std::vector<boost::shared_ptr<peer_connection> >::iterator remove_it
+				= std::remove_if(m_undead_peers.begin(), m_undead_peers.end()
+				, boost::bind(&boost::shared_ptr<peer_connection>::unique, _1));
+			m_undead_peers.erase(remove_it, m_undead_peers.end());
+			if (m_undead_peers.empty())
+			{
+				// we just removed our last "undead" peer (i.e. a peer connection
+				// that had some external reference to it). It's now safe to
+				// shut-down
+				if (m_abort)
+				{
+					m_io_service.post(boost::bind(&session_impl::abort_stage2, this));
+				}
+			}
+		}
+
 // too expensive
 //		INVARIANT_CHECK;
 
@@ -2939,10 +2964,13 @@ retry:
 		// until they're all closed
 		if (m_abort)
 		{
-			if (m_utp_socket_manager.num_sockets() == 0)
+			if (m_utp_socket_manager.num_sockets() == 0
+				&& m_undead_peers.empty())
 				return;
 #if defined TORRENT_ASIO_DEBUGGING
-			fprintf(stderr, "uTP sockets left: %d\n", m_utp_socket_manager.num_sockets());
+			fprintf(stderr, "uTP sockets left: %d undead-peers left: %d\n"
+				, m_utp_socket_manager.num_sockets()
+				, int(m_undead_peers.size()));
 #endif
 		}
 
@@ -2980,12 +3008,6 @@ retry:
 			update_dht_announce_interval();
 #endif
 
-		// remove undead peers that only have this list as their reference keeping them alive
-		std::vector<boost::shared_ptr<peer_connection> >::iterator remove_it
-			= std::remove_if(m_undead_peers.begin(), m_undead_peers.end()
-			, boost::bind(&boost::shared_ptr<peer_connection>::unique, _1));
-		m_undead_peers.erase(remove_it, m_undead_peers.end());
-
 		int tick_interval_ms = int(total_milliseconds(now - m_last_second_tick));
 		m_last_second_tick = now;
 		m_tick_residual += tick_interval_ms - 1000;
@@ -3604,6 +3626,8 @@ retry:
 					t->log_to_all_peers("auto manager starting (inactive) torrent");
 #endif
 				t->set_allow_peers(true);
+				t->update_gauge();
+				t->update_want_peers();
 				continue;
 			}
 
@@ -3620,6 +3644,8 @@ retry:
 					t->log_to_all_peers("auto manager starting torrent");
 #endif
 				t->set_allow_peers(true);
+				t->update_gauge();
+				t->update_want_peers();
 				continue;
 			}
 
@@ -3632,6 +3658,8 @@ retry:
 			t->set_announce_to_dht(false);
 			t->set_announce_to_trackers(false);
 			t->set_announce_to_lsd(false);
+			t->update_gauge();
+			t->update_want_peers();
 		}
 	}
 

src/torrent.cpp

@@ -516,44 +516,6 @@ namespace libtorrent
 	}
 #else // if 0
 
-	int torrent::current_stats_state() const
-	{
-		if (m_abort) return counters::num_checking_torrents + no_gauge_state;
-
-		if (has_error()) return counters::num_error_torrents;
-		if (!m_allow_peers || m_graceful_pause_mode)
-		{
-			if (!is_auto_managed()) return counters::num_stopped_torrents;
-			if (is_seed()) return counters::num_queued_seeding_torrents;
-			return counters::num_queued_download_torrents;
-		}
-		if (state() == torrent_status::checking_files
-#ifndef TORRENT_NO_DEPRECATE
-			|| state() == torrent_status::queued_for_checking
-#endif
-			)
-			return counters::num_checking_torrents;
-		else if (is_seed()) return counters::num_seeding_torrents;
-		else if (is_upload_only()) return counters::num_upload_only_torrents;
-		return counters::num_downloading_torrents;
-	}
-
-	void torrent::update_gauge()
-	{
-		int new_gauge_state = current_stats_state() - counters::num_checking_torrents;
-		TORRENT_ASSERT(new_gauge_state >= 0);
-		TORRENT_ASSERT(new_gauge_state <= no_gauge_state);
-
-		if (new_gauge_state == m_current_gauge_state) return;
-
-		if (m_current_gauge_state != no_gauge_state)
-			inc_stats_counter(m_current_gauge_state + counters::num_checking_torrents, -1);
-		if (new_gauge_state != no_gauge_state)
-			inc_stats_counter(new_gauge_state + counters::num_checking_torrents, 1);
-
-		m_current_gauge_state = new_gauge_state;
-	}
-
 	void torrent::on_torrent_download(error_code const& ec
 		, http_parser const& parser, char const* data, int size)
 	{
@@ -663,6 +625,45 @@ namespace libtorrent
 
 #endif // if 0
 
+	int torrent::current_stats_state() const
+	{
+		if (m_abort) return counters::num_checking_torrents + no_gauge_state;
+
+		if (has_error()) return counters::num_error_torrents;
+		if (!m_allow_peers || m_graceful_pause_mode)
+		{
+			if (!is_auto_managed()) return counters::num_stopped_torrents;
+			if (is_seed()) return counters::num_queued_seeding_torrents;
+			return counters::num_queued_download_torrents;
+		}
+		if (state() == torrent_status::checking_files
+#ifndef TORRENT_NO_DEPRECATE
+			|| state() == torrent_status::queued_for_checking
+#endif
+			)
+			return counters::num_checking_torrents;
+		else if (is_seed()) return counters::num_seeding_torrents;
+		else if (is_upload_only()) return counters::num_upload_only_torrents;
+		return counters::num_downloading_torrents;
+	}
+
+	void torrent::update_gauge()
+	{
+		int new_gauge_state = current_stats_state() - counters::num_checking_torrents;
+		TORRENT_ASSERT(new_gauge_state >= 0);
+		TORRENT_ASSERT(new_gauge_state <= no_gauge_state);
+
+		if (new_gauge_state == m_current_gauge_state) return;
+
+		if (m_current_gauge_state != no_gauge_state)
+			inc_stats_counter(m_current_gauge_state + counters::num_checking_torrents, -1);
+		if (new_gauge_state != no_gauge_state)
+			inc_stats_counter(new_gauge_state + counters::num_checking_torrents, 1);
+
+		m_current_gauge_state = new_gauge_state;
+	}
+
+
 	void torrent::leave_seed_mode(bool skip_checking)
 	{
 		if (!m_seed_mode) return;
@@ -9787,6 +9788,7 @@ namespace libtorrent
 				&& graceful == false)
 			{
 				m_graceful_pause_mode = graceful;
+				update_gauge();
 				do_pause();
 			}
 			return;