Time out when reliables can't be delivered

If one of the channels stalls for whatever reason we can't pretend the connection is fine.

src/network/connection.cpp

@@ -363,8 +363,19 @@ void ReliablePacketBuffer::incrementTimeouts(float dtime)
 	}
 }
 
+u32 ReliablePacketBuffer::getTimedOuts(float timeout)
+{
+	MutexAutoLock listlock(m_list_mutex);
+	u32 count = 0;
+	for (auto &packet : m_list) {
+		if (packet->totaltime >= timeout)
+			count++;
+	}
+	return count;
+}
+
 std::vector<ConstSharedPtr<BufferedPacket>>
-	ReliablePacketBuffer::getTimedOuts(float timeout, u32 max_packets)
+	ReliablePacketBuffer::getResend(float timeout, u32 max_packets)
 {
 	MutexAutoLock listlock(m_list_mutex);
 	std::vector<ConstSharedPtr<BufferedPacket>> timed_outs;
@@ -939,17 +950,22 @@ void Peer::RTTStatistics(float rtt, const std::string &profiler_id,
 	m_last_rtt = rtt;
 }
 
-bool Peer::isTimedOut(float timeout)
+bool Peer::isTimedOut(float timeout, std::string &reason)
 {
 	MutexAutoLock lock(m_exclusive_access_mutex);
-	u64 current_time = porting::getTimeMs();
 
-	float dtime = CALC_DTIME(m_last_timeout_check,current_time);
-	m_last_timeout_check = current_time;
+	{
+		u64 current_time = porting::getTimeMs();
+		float dtime = CALC_DTIME(m_last_timeout_check, current_time);
+		m_last_timeout_check = current_time;
+		m_timeout_counter += dtime;
+	}
+	if (m_timeout_counter > timeout) {
+		reason = "timeout counter";
+		return true;
+	}
 
-	m_timeout_counter += dtime;
-
-	return m_timeout_counter > timeout;
+	return false;
 }
 
 void Peer::Drop()
@@ -980,6 +996,24 @@ UDPPeer::UDPPeer(session_t a_id, Address a_address, Connection* connection) :
 		channel.setWindowSize(START_RELIABLE_WINDOW_SIZE);
 }
 
+bool UDPPeer::isTimedOut(float timeout, std::string &reason)
+{
+	if (Peer::isTimedOut(timeout, reason))
+		return true;
+
+	MutexAutoLock lock(m_exclusive_access_mutex);
+
+	for (int i = 0; i < CHANNEL_COUNT; i++) {
+		Channel &channel = channels[i];
+		if (channel.outgoing_reliables_sent.getTimedOuts(timeout) > 0) {
+			reason = "outgoing reliables channel=" + itos(i);
+			return true;
+		}
+	}
+
+	return false;
+}
+
 bool UDPPeer::getAddress(MTProtocols type,Address& toset)
 {
 	if ((type == MTP_UDP) || (type == MTP_MINETEST_RELIABLE_UDP) || (type == MTP_PRIMARY))

src/network/connection.h

@@ -262,7 +262,9 @@ class ReliablePacketBuffer
 	void insert(BufferedPacketPtr &p_ptr, u16 next_expected);
 
 	void incrementTimeouts(float dtime);
-	std::vector<ConstSharedPtr<BufferedPacket>> getTimedOuts(float timeout, u32 max_packets);
+	u32 getTimedOuts(float timeout);
+	// timeout relative to last resend
+	std::vector<ConstSharedPtr<BufferedPacket>> getResend(float timeout, u32 max_packets);
 
 	void print();
 	bool empty();
@@ -525,7 +527,7 @@ class Peer {
 		bool isHalfOpen() const { return m_half_open; }
 		void SetFullyOpen() { m_half_open = false; }
 
-		bool isTimedOut(float timeout);
+		virtual bool isTimedOut(float timeout, std::string &reason);
 
 		unsigned int m_increment_packets_remaining = 0;
 
@@ -636,6 +638,8 @@ class UDPPeer : public Peer
 	SharedBuffer<u8> addSplitPacket(u8 channel, BufferedPacketPtr &toadd,
 		bool reliable);
 
+	bool isTimedOut(float timeout, std::string &reason) override;
+
 protected:
 	/*
 		Calculates avg_rtt and resend_timeout.

src/network/connectionthreads.cpp

@@ -195,10 +195,11 @@ void ConnectionSendThread::runTimeouts(float dtime)
 		// Note that this time is also fixed since the timeout is not reset in half-open state.
 		const float peer_timeout = peer->isHalfOpen() ?
 			MYMAX(5.0f, m_timeout / 4) : m_timeout;
-		if (peer->isTimedOut(peer_timeout)) {
+		std::string reason;
+		if (peer->isTimedOut(peer_timeout, reason)) {
 			infostream << m_connection->getDesc()
 				<< "RunTimeouts(): Peer " << peer->id
-				<< " has timed out."
+				<< " has timed out (" << reason << ")"
 				<< std::endl;
 			// Add peer to the list
 			timeouted_peers.push_back(peer->id);
@@ -216,7 +217,7 @@ void ConnectionSendThread::runTimeouts(float dtime)
 			channel.outgoing_reliables_sent.incrementTimeouts(dtime);
 
 			// Re-send timed out outgoing reliables
-			auto timed_outs = channel.outgoing_reliables_sent.getTimedOuts(resend_timeout,
+			auto timed_outs = channel.outgoing_reliables_sent.getResend(resend_timeout,
 				(m_max_data_packets_per_iteration / numpeers));
 
 			channel.UpdatePacketLossCounter(timed_outs.size());
@@ -424,10 +425,10 @@ void ConnectionSendThread::processReliableCommand(ConnectionCommandPtr &c)
 				return;
 			Channel &channel = dynamic_cast<UDPPeer *>(&peer)->channels[c->channelnum];
 
-			auto timed_outs = channel.outgoing_reliables_sent.getTimedOuts(0, 1);
+			auto list = channel.outgoing_reliables_sent.getResend(0, 1);
 
-			if (!timed_outs.empty())
-				resendReliable(channel, timed_outs.front().get(), -1);
+			if (!list.empty())
+				resendReliable(channel, list.front().get(), -1);
 
 			return;
 		}