fix to start async operations inside the network thread to maintain thread safety within asio

src/session_impl.cpp

@@ -750,14 +750,26 @@ namespace aux {
 
 		url_random((char*)&m_peer_id[print.length()], (char*)&m_peer_id[0] + 20);
 
+		m_thread.reset(new thread(boost::bind(&session_impl::main_thread, this)));
+	}
+
+	void session_impl::start()
+	{
+		// this is where we should set up all async operations. This
+		// is called from within the network thread as opposed to the
+		// constructor which is called from the main thread
+
+		error_code ec;
 		m_timer.expires_from_now(milliseconds(m_settings.tick_interval), ec);
 		m_timer.async_wait(boost::bind(&session_impl::on_tick, this, _1));
+		TORRENT_ASSERT(!ec);
 
 		int delay = (std::max)(m_settings.local_service_announce_interval
 			/ (std::max)(int(m_torrents.size()), 1), 1);
 		m_lsd_announce_timer.expires_from_now(seconds(delay), ec);
 		m_lsd_announce_timer.async_wait(
 			boost::bind(&session_impl::on_lsd_announce, this, _1));
+		TORRENT_ASSERT(!ec);
 
 #ifndef TORRENT_DISABLE_DHT
 		delay = (std::max)(m_settings.dht_announce_interval
@@ -765,16 +777,17 @@ namespace aux {
 		m_dht_announce_timer.expires_from_now(seconds(delay), ec);
 		m_dht_announce_timer.async_wait(
 			boost::bind(&session_impl::on_dht_announce, this, _1));
+		TORRENT_ASSERT(!ec);
 #endif
 
 		// no reuse_address
 		open_listen_port(false);
-
-		m_thread.reset(new thread(boost::bind(&session_impl::main_thread, this)));
 	}
 
 	void session_impl::save_state(entry* eptr, boost::uint32_t flags) const
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		entry& e = *eptr;
 
 		if (flags & session::save_settings)
@@ -836,6 +849,8 @@ namespace aux {
 	
 	void session_impl::set_proxy(proxy_settings const& s)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		m_proxy = s;
 		// in case we just set a socks proxy, we might have to
 		// open the socks incoming connection
@@ -845,6 +860,8 @@ namespace aux {
 
 	void session_impl::load_state(lazy_entry const* e)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		lazy_entry const* settings;
 	  
 		if (e->type() != lazy_entry::dict_t) return;
@@ -927,12 +944,16 @@ namespace aux {
 
 	char const* session_impl::country_for_ip(address const& a)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (!a.is_v4() || m_country_db == 0) return 0;
 		return GeoIP_country_code_by_ipnum(m_country_db, a.to_v4().to_ulong());
 	}
 
 	int session_impl::as_for_ip(address const& a)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (!a.is_v4() || m_asnum_db == 0) return 0;
 		char* name = GeoIP_name_by_ipnum(m_asnum_db, a.to_v4().to_ulong());
 		if (name == 0) return 0;
@@ -943,6 +964,8 @@ namespace aux {
 
 	std::string session_impl::as_name_for_ip(address const& a)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (!a.is_v4() || m_asnum_db == 0) return std::string();
 		char* name = GeoIP_name_by_ipnum(m_asnum_db, a.to_v4().to_ulong());
 		if (name == 0) return std::string();
@@ -954,6 +977,8 @@ namespace aux {
 
 	std::pair<const int, int>* session_impl::lookup_as(int as)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		std::map<int, int>::iterator i = m_as_peak.lower_bound(as);
 
 		if (i == m_as_peak.end() || i->first != as)
@@ -966,6 +991,8 @@ namespace aux {
 
 	void session_impl::load_asnum_db(std::string file)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_asnum_db) GeoIP_delete(m_asnum_db);
 		m_asnum_db = GeoIP_open(file.c_str(), GEOIP_STANDARD);
 //		return m_asnum_db;
@@ -974,6 +1001,8 @@ namespace aux {
 #if TORRENT_USE_WSTRING
 	void session_impl::load_asnum_dbw(std::wstring file)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_asnum_db) GeoIP_delete(m_asnum_db);
 		std::string utf8;
 		wchar_utf8(file, utf8);
@@ -983,6 +1012,8 @@ namespace aux {
 
 	void session_impl::load_country_dbw(std::wstring file)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_country_db) GeoIP_delete(m_country_db);
 		std::string utf8;
 		wchar_utf8(file, utf8);
@@ -993,6 +1024,8 @@ namespace aux {
 
 	void session_impl::load_country_db(std::string file)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_country_db) GeoIP_delete(m_country_db);
 		m_country_db = GeoIP_open(file.c_str(), GEOIP_STANDARD);
 //		return m_country_db;
@@ -1004,6 +1037,7 @@ namespace aux {
 	void session_impl::add_extension(
 		boost::function<boost::shared_ptr<torrent_plugin>(torrent*, void*)> ext)
 	{
+		TORRENT_ASSERT(is_network_thread());
 		TORRENT_ASSERT_VAL(ext, ext);
 
 		typedef boost::shared_ptr<torrent_plugin>(*function_t)(torrent*, void*);
@@ -1022,12 +1056,16 @@ namespace aux {
 #ifndef TORRENT_DISABLE_DHT
 	void session_impl::add_dht_node(udp::endpoint n)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_dht) m_dht->add_node(n);
 	}
 #endif
 
 	void session_impl::pause()
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_paused) return;
 #if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
 		(*m_logger) << time_now_string() << " *** session paused ***\n";
@@ -1043,6 +1081,8 @@ namespace aux {
 
 	void session_impl::resume()
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (!m_paused) return;
 		m_paused = false;
 		for (torrent_map::iterator i = m_torrents.begin()
@@ -1055,6 +1095,8 @@ namespace aux {
 	
 	void session_impl::abort()
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		if (m_abort) return;
 #if defined TORRENT_LOGGING
 		(*m_logger) << time_now_string() << " *** ABORT CALLED ***\n";
@@ -1449,6 +1491,8 @@ namespace aux {
 	
 	void session_impl::open_listen_port(bool reuse_address)
 	{
+		TORRENT_ASSERT(is_network_thread());
+
 		// close the open listen sockets
 		m_listen_sockets.clear();
 		m_incoming_connection = false;
@@ -3028,6 +3072,9 @@ namespace aux {
 		TORRENT_ASSERT(is_network_thread());
 		eh_initializer();
 
+		// initialize async operations
+		start();
+
 		bool stop_loop = false;
 		while (!stop_loop)
 		{