Some audio backend cleanup / refactor

gtk2_ardour/ardour_ui_startup.cc

@@ -866,7 +866,7 @@ ARDOUR_UI::load_from_application_api (const std::string& path)
 #else
 					"JACK",
 #endif
-					ARDOUR_COMMAND_LINE::backend_client_name, "")) {
+					ARDOUR_COMMAND_LINE::backend_session_id, "")) {
 			error << _("NSM: The JACK backend is mandatory and can not be loaded.") << endmsg;
 			return;
 		}

gtk2_ardour/engine_dialog.cc

@@ -1024,7 +1024,7 @@ EngineControl::backend_changed ()
 	string                                  backend_name = backend_combo.get_active_text ();
 	std::shared_ptr<ARDOUR::AudioBackend> backend;
 
-	if (!(backend = ARDOUR::AudioEngine::instance ()->set_backend (backend_name, ARDOUR_COMMAND_LINE::backend_client_name, ""))) {
+	if (!(backend = ARDOUR::AudioEngine::instance ()->set_backend (backend_name, ARDOUR_COMMAND_LINE::backend_session_id, ""))) {
 		/* eh? setting the backend failed... how ? */
 		/* A: stale config contains a backend that does not exist in current build */
 		return;
@@ -1146,7 +1146,7 @@ EngineControl::get_default_device (const string&         current_device_name,
 	using namespace ARDOUR;
 
 	string default_device_name =
-	    AudioBackend::get_standard_device_name (AudioBackend::DeviceDefault);
+	    AudioBackend::get_default_device_name ();
 
 	vector<string>::const_iterator i;
 
@@ -1158,7 +1158,7 @@ EngineControl::get_default_device (const string&         current_device_name,
 	}
 
 	string none_device_name =
-	    AudioBackend::get_standard_device_name (AudioBackend::DeviceNone);
+	    AudioBackend::get_none_device_name ();
 
 	// Use the first device that isn't "None"
 	for (i = available_devices.begin (); i != available_devices.end (); ++i) {
@@ -1581,7 +1581,7 @@ EngineControl::input_device_changed ()
 
 	std::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance ()->current_backend ();
 	if (backend && backend->match_input_output_devices_or_none ()) {
-		const std::string& dev_none = ARDOUR::AudioBackend::get_standard_device_name (ARDOUR::AudioBackend::DeviceNone);
+		const std::string& dev_none = ARDOUR::AudioBackend::get_none_device_name ();
 
 		if (get_output_device_name () != dev_none && get_input_device_name () != dev_none && get_input_device_name () != get_output_device_name ()) {
 			block_changed_signals ();
@@ -1603,7 +1603,7 @@ EngineControl::output_device_changed ()
 	DEBUG_ECONTROL ("output_device_changed");
 	std::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance ()->current_backend ();
 	if (backend && backend->match_input_output_devices_or_none ()) {
-		const std::string& dev_none = ARDOUR::AudioBackend::get_standard_device_name (ARDOUR::AudioBackend::DeviceNone);
+		const std::string& dev_none = ARDOUR::AudioBackend::get_none_device_name ();
 
 		if (get_input_device_name () != dev_none && get_input_device_name () != dev_none && get_input_device_name () != get_output_device_name ()) {
 			block_changed_signals ();
@@ -2207,7 +2207,7 @@ EngineControl::set_current_state (const State& state)
 
 	std::shared_ptr<ARDOUR::AudioBackend> backend;
 
-	if (!(backend = ARDOUR::AudioEngine::instance ()->set_backend (state->backend, ARDOUR_COMMAND_LINE::backend_client_name, ""))) {
+	if (!(backend = ARDOUR::AudioEngine::instance ()->set_backend (state->backend, ARDOUR_COMMAND_LINE::backend_session_id, ""))) {
 		DEBUG_ECONTROL (string_compose ("Unable to set backend to %1", state->backend));
 		// this shouldn't happen as the invalid backend names should have been
 		// removed from the list of states.
@@ -2489,7 +2489,7 @@ EngineControl::push_state_to_backend (bool start)
 		error << string_compose (_("Cannot set buffer size to %1"), get_buffer_size ()) << endmsg;
 		return 1;
 	}
-	if (change_nperiods && backend->set_peridod_size (get_nperiods ())) {
+	if (change_nperiods && backend->set_period_size (get_nperiods ())) {
 		error << string_compose (_("Cannot set periods to %1"), get_nperiods ()) << endmsg;
 		return 1;
 	}

gtk2_ardour/nsm.cc

@@ -49,7 +49,7 @@ NSM_Client::command_open(const char* name,
 {
 	int r = ERR_OK;
 
-	ARDOUR_COMMAND_LINE::backend_client_name = client_id;
+	ARDOUR_COMMAND_LINE::backend_session_id = client_id;
 	ARDOUR_COMMAND_LINE::session_name = "";
 
 	/* this appears asynchronous, but almost certainly is

gtk2_ardour/opts.cc

@@ -41,7 +41,7 @@
 using namespace std;
 
 string ARDOUR_COMMAND_LINE::session_name = "";
-string ARDOUR_COMMAND_LINE::backend_client_name = PBD::downcase(PROGRAM_NAME);
+string ARDOUR_COMMAND_LINE::backend_session_id = PBD::downcase(PROGRAM_NAME);
 bool  ARDOUR_COMMAND_LINE::show_key_actions = false;
 bool  ARDOUR_COMMAND_LINE::show_actions = false;
 bool ARDOUR_COMMAND_LINE::no_splash = false;
@@ -72,7 +72,7 @@ print_help (const char *execname)
 		<< _("  -A, --actions               Print all possible menu action names\n")
 		<< _("  -b, --bindings              Display all current key bindings\n")
 		<< _("  -B, --bypass-plugins        Bypass all plugins in an existing session\n")
-		<< _("  -c, --name <name>           Use a specific backend client name, default is ardour\n")
+		<< _("  -c, --name <session-id>     Specify audio backend client session id, default is ardour\n")
 		<< _("  -d, --disable-plugins       Disable all plugins (safe mode)\n")
 #ifndef NDEBUG
 		<< _("  -D, --debug <options>       Set debug flags. Use \"-D list\" to see available options\n")
@@ -218,7 +218,7 @@ ARDOUR_COMMAND_LINE::parse_opts (int argc, char *argv[])
 			break;
 
 		case 'c':
-			backend_client_name = optarg;
+			backend_session_id = optarg;
 			break;
 
 		case 'k':

gtk2_ardour/opts.h

@@ -29,7 +29,7 @@ extern bool        show_key_actions;
 extern bool        show_actions;
 extern bool        no_splash;
 extern bool        just_version;
-extern std::string backend_client_name;
+extern std::string backend_session_id;
 extern bool        new_session;
 extern bool        try_hw_optimization;
 extern bool        no_connect_ports;

headless/load_session.cc

@@ -48,7 +48,7 @@ using namespace PBD;
 
 static const char* localedir = LOCALEDIR;
 
-static string             backend_client_name;
+static string             backend_session_id;
 static CrossThreadChannel xthread (true);
 static TestReceiver       test_receiver;
 
@@ -72,7 +72,7 @@ load_session (string dir, string state)
 
 	AudioEngine* engine = AudioEngine::create ();
 
-	if (!engine->set_backend (backend_name, backend_client_name, "")) {
+	if (!engine->set_backend (backend_name, backend_session_id, "")) {
 		std::cerr << "Cannot set Audio/MIDI engine backend\n";
 		exit (EXIT_FAILURE);
 	}
@@ -172,7 +172,7 @@ main (int argc, char* argv[])
 
 	bool try_hw_optimization = true;
 
-	backend_client_name = PBD::downcase (std::string (PROGRAM_NAME));
+	backend_session_id = PBD::downcase (std::string (PROGRAM_NAME));
 
 	int c;
 	while ((c = getopt_long (argc, argv, optstring, longopts, (int*)0)) != EOF) {
@@ -191,7 +191,7 @@ main (int argc, char* argv[])
 				break;
 
 			case 'c':
-				backend_client_name = optarg;
+				backend_session_id = optarg;
 				break;
 
 			case 'B':

libs/ardour/ardour/audio_backend.h

@@ -44,11 +44,11 @@ namespace ARDOUR
 struct LIBARDOUR_API AudioBackendInfo {
 	const char* name;
 
-	/** Using arg1 and arg2, initialize this audiobackend.
+	/** Using client_name and session_id, initialize this audiobackend.
 	 *
 	 * Returns zero on success, non-zero otherwise.
 	 */
-	int (*instantiate) (const std::string& arg1, const std::string& arg2);
+	int (*instantiate) (const std::string& client_name, const std::string& session_id);
 
 	/** Release all resources associated with this audiobackend */
 	int (*deinstantiate) (void);
@@ -131,12 +131,8 @@ class LIBARDOUR_API AudioBackend : public PortEngine
 
 	static std::string get_error_string (ErrorCode);
 
-	enum StandardDeviceName {
-		DeviceNone,
-		DeviceDefault
-	};
-
-	static std::string get_standard_device_name (StandardDeviceName);
+	static std::string get_none_device_name ();
+	static std::string get_default_device_name ();
 
 	/** Return the AudioBackendInfo object from which this backend
 	 * was constructed.
@@ -153,15 +149,10 @@ class LIBARDOUR_API AudioBackend : public PortEngine
 	 */
 	virtual std::string name () const = 0;
 
-	/** Return true if the callback from the underlying mechanism/API
-	 * (CoreAudio, JACK, ASIO etc.) occurs in a thread subject to realtime
-	 * constraints. Return false otherwise.
-	 */
-	virtual bool is_realtime () const = 0;
-
-	/** Return true if the backed is JACK */
+	/** Return true if the backend is JACK */
 	virtual bool is_jack () const { return false; }
 
+	/** Return the priority to be set with pbd_set_engine_rt_priority. */
 	virtual int client_real_time_priority () { return 0; }
 
 	/* Discovering devices and parameters */
@@ -232,7 +223,7 @@ class LIBARDOUR_API AudioBackend : public PortEngine
 	 * of allowing one to be "None".
 	 *
 	 * ie. Input Device must match Output Device, except if either of them
-	 * is get_standard_device_name (DeviceNone).
+	 * is get_none_device_name ().
 	 */
 	virtual bool match_input_output_devices_or_none () const
 	{
@@ -291,7 +282,7 @@ class LIBARDOUR_API AudioBackend : public PortEngine
 	/** Set the period size to be used.
 	 * must be called before starting the backend.
 	 */
-	virtual int set_peridod_size (uint32_t)
+	virtual int set_period_size (uint32_t)
 	{
 		return -1;
 	}

libs/ardour/ardour/audioengine.h

@@ -71,7 +71,7 @@ class LIBARDOUR_API AudioEngine : public PortManager, public SessionHandlePtr
 	int discover_backends();
 	std::vector<const AudioBackendInfo*> available_backends() const;
 	std::string current_backend_name () const;
-	std::shared_ptr<AudioBackend> set_backend (const std::string&, const std::string& arg1, const std::string& arg2);
+	std::shared_ptr<AudioBackend> set_backend (const std::string& name, const std::string& client_name, const std::string& session_id);
 	std::shared_ptr<AudioBackend> current_backend() const { return _backend; }
 	bool setup_required () const;
 	bool is_jack () const;

libs/ardour/audio_backend.cc

@@ -100,15 +100,15 @@ AudioBackend::get_error_string (ErrorCode error_code)
 }
 
 std::string
-AudioBackend::get_standard_device_name (StandardDeviceName device_name)
+AudioBackend::get_none_device_name ()
 {
-	switch (device_name) {
-	case DeviceNone:
-		return _("None");
-	case DeviceDefault:
-		return _("Default");
-	}
-	return std::string();
+	return _("None");
+}
+
+std::string
+AudioBackend::get_default_device_name ()
+{
+	return _("Default");
 }
 
 } // namespace ARDOUR

libs/ardour/audioengine.cc

@@ -1015,7 +1015,7 @@ AudioEngine::drop_backend ()
 }
 
 std::shared_ptr<AudioBackend>
-AudioEngine::set_backend (const std::string& name, const std::string& arg1, const std::string& arg2)
+AudioEngine::set_backend (const std::string& name, const std::string& client_name, const std::string& session_id)
 {
 	BackendMap::iterator b = _backends.find (name);
 
@@ -1026,7 +1026,7 @@ AudioEngine::set_backend (const std::string& name, const std::string& arg1, cons
 	drop_backend ();
 
 	try {
-		if (b->second->instantiate (arg1, arg2)) {
+		if (b->second->instantiate (client_name, session_id)) {
 			throw failed_constructor ();
 		}
 
@@ -1067,11 +1067,7 @@ AudioEngine::start (bool for_latency)
 		return -1;
 	}
 
-	if (_backend->is_realtime ()) {
-		pbd_set_engine_rt_priority (_backend->client_real_time_priority ());
-	} else {
-		pbd_set_engine_rt_priority (0);
-	}
+	pbd_set_engine_rt_priority (_backend->client_real_time_priority ());
 
 	_running = true;
 

libs/ardour/luabindings.cc

@@ -2920,7 +2920,7 @@ LuaBindings::common (lua_State* L)
 
 		.addFunction ("set_sample_rate", &AudioBackend::set_sample_rate)
 		.addFunction ("set_buffer_size", &AudioBackend::set_buffer_size)
-		.addFunction ("set_peridod_size", &AudioBackend::set_peridod_size)
+		.addFunction ("set_period_size", &AudioBackend::set_period_size)
 
 		.addFunction ("enumerate_drivers", &AudioBackend::enumerate_drivers)
 		.addFunction ("driver_name", &AudioBackend::driver_name)