Make the backend usable only after it responds to initial PING

include/transport/networkpluginserver.h

@@ -84,6 +84,7 @@ class NetworkPluginServer {
 	private:
 		void handleNewClientConnection(boost::shared_ptr<Swift::Connection> c);
 		void handleSessionFinished(Backend *c);
+		void handlePongReceived(Backend *c);
 		void handleDataRead(Backend *c, boost::shared_ptr<Swift::SafeByteArray> data);
 
 		void handleConnectedPayload(const std::string &payload);

spectrum/src/main.cpp

@@ -207,6 +207,16 @@ int main(int argc, char **argv)
 		std::cerr << "Can't create service.working_dir directory " << CONFIG_STRING(&config, "service.working_dir") << ".\n";
 		return 1;
 	}
+	// create directories
+	try {
+		boost::filesystem::create_directories(
+			boost::filesystem::path(CONFIG_STRING(&config, "service.portfile")).parent_path().string()
+		);
+	}
+	catch (...) {
+		std::cerr << "Can't create service.portfile directory " << CONFIG_STRING(&config, "service.portfile") << ".\n";
+		return 1;
+	}
 
 #ifndef WIN32
 	if (!CONFIG_STRING(&config, "service.group").empty() ||!CONFIG_STRING(&config, "service.user").empty() ) {
@@ -223,6 +233,20 @@ int main(int argc, char **argv)
 		chown(CONFIG_STRING(&config, "service.working_dir").c_str(), pw->pw_uid, gr->gr_gid);
 	}
 
+	char backendport[20];
+	FILE* port_file_f;
+	port_file_f = fopen(CONFIG_STRING(&config, "service.portfile").c_str(), "w+");
+	if (port_file_f == NULL) {
+		std::cerr << "Cannot create port_file file " << CONFIG_STRING(&config, "service.portfile").c_str() << ". Exiting\n";
+		exit(1);
+	}
+	sprintf(backendport,"%s\n",CONFIG_STRING(&config, "service.backend_port").c_str());
+	if (fwrite(backendport,1,strlen(backendport),port_file_f) < strlen(backendport)) {
+		std::cerr << "Cannot write to port file " << CONFIG_STRING(&config, "service.portfile") << ". Exiting\n";
+		exit(1);
+	}
+	fclose(port_file_f);
+
 	if (!no_daemon) {
 		// daemonize
 		daemonize(CONFIG_STRING(&config, "service.working_dir").c_str(), CONFIG_STRING(&config, "service.pidfile").c_str());

src/config.cpp

@@ -75,6 +75,7 @@ bool Config::load(std::istream &ifs, boost::program_options::options_description
 		("service.backend", value<std::string>()->default_value("libpurple_backend"), "Backend")
 		("service.protocol", value<std::string>()->default_value(""), "Protocol")
 		("service.pidfile", value<std::string>()->default_value("/var/run/spectrum2/$jid.pid"), "Full path to pid file")
+		("service.portfile", value<std::string>()->default_value("/var/run/spectrum2/$jid.port"), "File to store backend_port to. It's used by spectrum2_manager.")
 		("service.working_dir", value<std::string>()->default_value("/var/lib/spectrum2/$jid"), "Working dir")
 		("service.allowed_servers", value<std::vector<std::string> >()->multitoken(), "Only users from these servers can connect")
 		("service.server_mode", value<bool>()->default_value(false), "True if Spectrum should behave as server")

src/networkpluginserver.cpp

@@ -318,18 +318,14 @@ void NetworkPluginServer::handleNewClientConnection(boost::shared_ptr<Swift::Con
 	client->res = 0;
 	client->init_res = 0;
 	client->shared = 0;
-	client->willDie = 0;
+	// Until we receive first PONG from backend, backend is in willDie state.
+	client->willDie = true;
 	// Backend does not accept new clients automatically if it's long-running
 	client->acceptUsers = !m_isNextLongRun;
 	client->longRun = m_isNextLongRun;
 
 	LOG4CXX_INFO(logger, "New" + (client->longRun ? std::string(" long-running") : "") +  " backend " << client << " connected. Current backend count=" << (m_clients.size() + 1));
 
-	if (m_clients.size() == 0) {
-		// first backend connected, start the server, we're ready.
-		m_component->start();
-	}
-
 	m_clients.push_front(client);
 
 	c->onDisconnected.connect(boost::bind(&NetworkPluginServer::handleSessionFinished, this, client));
@@ -340,28 +336,6 @@ void NetworkPluginServer::handleNewClientConnection(boost::shared_ptr<Swift::Con
 	// in first ::pingTimeout call, because it can be called right after this function
 	// and backend wouldn't have any time to response to ping.
 	client->pongReceived = -1;
-
-	// some users are in queue waiting for this backend
-	while(!m_waitingUsers.empty()) {
-		// There's no new backend, so stop associating users and wait for new backend,
-		// which has been already spawned in getFreeClient() call.
-		if (getFreeClient() == NULL)
-			break;
-
-		User *u = m_waitingUsers.front();
-		m_waitingUsers.pop_front();
-
-		LOG4CXX_INFO(logger, "Associating " << u->getJID().toString() << " with this backend");
-
-		// associate backend with user
-		handleUserCreated(u);
-
-		// connect user if it's ready
-		if (u->isReadyToConnect()) {
-			handleUserReadyToConnect(u);
-		}
-
-	}
 }
 
 void NetworkPluginServer::handleSessionFinished(Backend *c) {
@@ -753,6 +727,42 @@ void NetworkPluginServer::handleFTDataNeeded(Backend *b, unsigned long ftid) {
 	send(b->connection, message);
 }
 
+void NetworkPluginServer::handlePongReceived(Backend *c) {
+	// This could be first PONG from the backend
+	if (c->pongReceived == -1) {
+		// Backend is fully ready to handle requests
+		c->willDie = false;
+
+		if (m_clients.size() == 1) {
+			// first backend connected, start the server, we're ready.
+			m_component->start();
+		}
+
+		// some users are in queue waiting for this backend
+		while(!m_waitingUsers.empty()) {
+			// There's no new backend, so stop associating users and wait for new backend,
+			// which has been already spawned in getFreeClient() call.
+			if (getFreeClient() == NULL)
+				break;
+
+			User *u = m_waitingUsers.front();
+			m_waitingUsers.pop_front();
+
+			LOG4CXX_INFO(logger, "Associating " << u->getJID().toString() << " with this backend");
+
+			// associate backend with user
+			handleUserCreated(u);
+
+			// connect user if it's ready
+			if (u->isReadyToConnect()) {
+				handleUserReadyToConnect(u);
+			}
+		}
+	}
+
+	c->pongReceived = true;
+}
+
 void NetworkPluginServer::handleDataRead(Backend *c, boost::shared_ptr<Swift::SafeByteArray> data) {
 	// Append data to buffer
 	c->data.insert(c->data.end(), data->begin(), data->end());
@@ -803,7 +813,7 @@ void NetworkPluginServer::handleDataRead(Backend *c, boost::shared_ptr<Swift::Sa
 				handleConvMessagePayload(wrapper.payload(), true);
 				break;
 			case pbnetwork::WrapperMessage_Type_TYPE_PONG:
-				c->pongReceived = true;
+				handlePongReceived(c);
 				break;
 			case pbnetwork::WrapperMessage_Type_TYPE_PARTICIPANT_CHANGED:
 				handleParticipantChangedPayload(wrapper.payload());
@@ -897,7 +907,11 @@ void NetworkPluginServer::pingTimeout() {
 		// pong has been received OR backend just connected and did not have time to answer the ping
 		// request.
 		if ((*it)->pongReceived || (*it)->pongReceived == -1) {
-			sendPing((*it));
+			// Don't send another ping if pongReceived == -1, because we've already sent one
+			// when registering backend.
+			if ((*it)->pongReceived) {
+				sendPing((*it));
+			}
 		}
 		else {
 			LOG4CXX_INFO(logger, "Disconnecting backend " << (*it) << " (ID=" << (*it)->id << "). PING response not received.");