added session::set_alert_dispatch() for system specific message loop integration

include/libtorrent/alert.hpp

@@ -130,12 +130,15 @@ namespace libtorrent {
 		size_t alert_queue_size_limit() const { return m_queue_size_limit; }
 		size_t set_alert_queue_size_limit(size_t queue_size_limit_);
 
+		void set_dispatch_function(boost::function<void(alert const&)> const&);
+
 	private:
 		std::queue<alert*> m_alerts;
 		mutable boost::mutex m_mutex;
 		boost::condition m_condition;
 		int m_alert_mask;
 		size_t m_queue_size_limit;
+		boost::function<void(alert const&)> m_dispatch;
 	};
 
 	struct TORRENT_EXPORT unhandled_alert : std::exception

include/libtorrent/aux_/session_impl.hpp

@@ -216,6 +216,7 @@ namespace libtorrent
 			void set_alert_mask(int m);
 			size_t set_alert_queue_size_limit(size_t queue_size_limit_);
 			std::auto_ptr<alert> pop_alert();
+			void set_alert_dispatch(boost::function<void(alert const&)> const&);
 
 			alert const* wait_for_alert(time_duration max_wait);
 

include/libtorrent/session.hpp

@@ -378,6 +378,7 @@ namespace libtorrent
 		size_t set_alert_queue_size_limit(size_t queue_size_limit_);
 
 		alert const* wait_for_alert(time_duration max_wait);
+		void set_alert_dispatch(boost::function<void(alert const&)> const& fun);
 
 		connection_queue& get_connection_queue();
 

src/alert.cpp

@@ -80,10 +80,31 @@ namespace libtorrent {
 		return m_alerts.front();
 	}
 
+	void alert_manager::set_dispatch_function(boost::function<void(alert const&)> const& fun)
+	{
+		boost::mutex::scoped_lock lock(m_mutex);
+
+		m_dispatch = fun;
+
+		while (!m_alerts.empty())
+		{
+			m_dispatch(*m_alerts.front());
+			delete m_alerts.front();
+			m_alerts.pop();
+		}
+	}
+
 	void alert_manager::post_alert(const alert& alert_)
 	{
 		boost::mutex::scoped_lock lock(m_mutex);
 
+		if (m_dispatch)
+		{
+			TORRENT_ASSERT(m_alerts.empty());
+			m_dispatch(alert_);
+			return;
+		}
+
 		if (m_alerts.size() >= m_queue_size_limit) return;
 		m_alerts.push(alert_.clone().release());
 		m_condition.notify_all();

src/session.cpp

@@ -565,6 +565,11 @@ namespace libtorrent
 		return m_impl->pop_alert();
 	}
 
+	void session::set_alert_dispatch(boost::function<void(alert const&)> const& fun)
+	{
+		return m_impl->set_alert_dispatch(fun);
+	}
+
 	alert const* session::wait_for_alert(time_duration max_wait)
 	{
 		return m_impl->wait_for_alert(max_wait);

src/session_impl.cpp

@@ -2425,6 +2425,12 @@ namespace aux {
 		m_bandwidth_manager[peer_connection::upload_channel]->throttle(bytes_per_second);
 	}
 
+	void session_impl::set_alert_dispatch(boost::function<void(alert const&)> const& fun)
+	{
+		mutex_t::scoped_lock l(m_mutex);
+		m_alerts.set_dispatch_function(fun);
+	}
+
 	std::auto_ptr<alert> session_impl::pop_alert()
 	{
 		mutex_t::scoped_lock l(m_mutex);

test/test_transfer.cpp

@@ -101,6 +101,11 @@ void test_rate()
 
 }
 
+void print_alert(alert const& a)
+{
+	std::cout << "ses1 (alert dispatch function): " << a.message() << std::endl;
+}
+
 void test_transfer()
 {
 	session ses1(fingerprint("LT", 0, 1, 0, 0), std::make_pair(48075, 49000));
@@ -134,6 +139,7 @@ void test_transfer()
 
 	ses1.set_alert_mask(alert::all_categories & ~alert::progress_notification);
 	ses2.set_alert_mask(alert::all_categories & ~alert::progress_notification);
+	ses1.set_alert_dispatch(&print_alert);
 
 	for (int i = 0; i < 30; ++i)
 	{