Detach/Reattach from/to Jack from UI (ticket #180).

git-svn-id: http://svn.drobilla.net/lad/trunk/ingen@1985 a436a847-0d15-0410-975c-d299462d15a1

20 files changed, 214 insertions, 185 deletions

diff --git a/src/engine/Driver.hpp b/src/engine/Driver.hpp
index a2ca6b15..e03c316d 100644
--- a/src/engine/Driver.hpp
+++ b/src/engine/Driver.hpp
@@ -46,7 +46,8 @@ public:
 	/** Set the name of the system port */
 	virtual void set_name(const std::string& name) = 0;
 
-	virtual void unregister() = 0;
+	virtual void create()  = 0;
+	virtual void destroy() = 0;
 	
 	bool        is_input()   const { return _patch_port->is_input(); }
 	DuplexPort* patch_port() const { return _patch_port; }
diff --git a/src/engine/Engine.cpp b/src/engine/Engine.cpp
index 41004b97..4d984916 100644
--- a/src/engine/Engine.cpp
+++ b/src/engine/Engine.cpp
@@ -22,26 +22,26 @@
 #include "raul/Deletable.hpp"
 #include "raul/Maid.hpp"
 #include "raul/SharedPtr.hpp"
-#include "Engine.hpp"	
-#include "tuning.hpp"
-#include "Event.hpp"
-#include "common/interface/EventType.hpp"
-#include "shared/Store.hpp"
-#include "NodeFactory.hpp"
+#include "AudioDriver.hpp"
 #include "ClientBroadcaster.hpp"
-#include "PatchImpl.hpp"
+#include "Engine.hpp"	
 #include "EngineStore.hpp"
+#include "Event.hpp"
+#include "MessageContext.hpp"
 #include "MidiDriver.hpp"
+#include "NodeFactory.hpp"
 #include "OSCDriver.hpp"
-#include "QueuedEventSource.hpp"
+#include "PatchImpl.hpp"
 #include "PostProcessor.hpp"
-#include "events/CreatePatchEvent.hpp"
 #include "PostProcessor.hpp"
-#include "AudioDriver.hpp"
-#include "ProcessSlave.hpp"
 #include "ProcessContext.hpp"
-#include "MessageContext.hpp"
+#include "ProcessSlave.hpp"
+#include "QueuedEventSource.hpp"
 #include "ThreadManager.hpp"
+#include "common/interface/EventType.hpp"
+#include "events/CreatePatchEvent.hpp"
+#include "shared/Store.hpp"
+#include "tuning.hpp"
 using namespace std;
 
 namespace Ingen {
@@ -182,20 +182,21 @@ Engine::activate(size_t parallelism)
 		_midi_driver = new DummyMidiDriver();
 	
 	for (EventSources::iterator i = _event_sources.begin(); i != _event_sources.end(); ++i)
-		(*i)->activate();
+		(*i)->activate_source();
 
 	// Create root patch
-
-	PatchImpl* root_patch = new PatchImpl(*this, "", 1, NULL,
-			_audio_driver->sample_rate(), _audio_driver->buffer_size(), 1);
-	root_patch->activate();
-	_world->store->add(root_patch);
-	root_patch->compiled_patch(root_patch->compile());
-
-	assert(_audio_driver->root_patch() == NULL);
-	_audio_driver->set_root_patch(root_patch);
+	PatchImpl* root_patch = _audio_driver->root_patch();
+	if (!root_patch) {
+		root_patch = new PatchImpl(*this, "", 1, NULL,
+				_audio_driver->sample_rate(), _audio_driver->buffer_size(), 1);
+		root_patch->activate();
+		_world->store->add(root_patch);
+		root_patch->compiled_patch(root_patch->compile());
+		_audio_driver->set_root_patch(root_patch);
+	}
 
 	_audio_driver->activate();
+	_midi_driver->attach(*_audio_driver.get());
 
 	_process_slaves.clear();
 	_process_slaves.reserve(parallelism);
@@ -219,34 +220,31 @@ Engine::deactivate()
 		return;
 	
 	for (EventSources::iterator i = _event_sources.begin(); i != _event_sources.end(); ++i)
-		(*i)->deactivate();
+		(*i)->deactivate_source();
 
 	/*for (Tree<GraphObject*>::iterator i = _engine_store->objects().begin();
 			i != _engine_store->objects().end(); ++i)
 		if ((*i)->as_node() != NULL && (*i)->as_node()->parent() == NULL)
 			(*i)->as_node()->deactivate();*/
 	
-	_audio_driver->deactivate();
-	
-	if (_midi_driver != NULL) {
+	if (_midi_driver)
 		_midi_driver->deactivate();
-		delete _midi_driver;
-		_midi_driver = NULL;
-	}
+
+	_audio_driver->deactivate();
 
 	_audio_driver->root_patch()->deactivate();
 	
-	for (size_t i=0; i < _process_slaves.size(); ++i) {
+	/*for (size_t i=0; i < _process_slaves.size(); ++i) {
 		delete _process_slaves[i];
-	}
+	}*/
 	
-	_process_slaves.clear();
+	//_process_slaves.clear();
 
 	// Finalize any lingering events (unlikely)
-	_post_processor->process();
+	//_post_processor->process();
 
-	_audio_driver.reset();
-	_event_sources.clear();
+	//_audio_driver.reset();
+	//_event_sources.clear();
 	
 	_activated = false;
 }
diff --git a/src/engine/EventSource.hpp b/src/engine/EventSource.hpp
index f3377393..1e36c2da 100644
--- a/src/engine/EventSource.hpp
+++ b/src/engine/EventSource.hpp
@@ -43,8 +43,8 @@ class EventSource
 public:
 	virtual ~EventSource() {}
 
-	virtual void activate()   = 0;
-	virtual void deactivate() = 0;
+	virtual void activate_source()   = 0;
+	virtual void deactivate_source() = 0;
 
 	virtual void process(PostProcessor& dest, ProcessContext& context) = 0;
 };
diff --git a/src/engine/HTTPEngineReceiver.cpp b/src/engine/HTTPEngineReceiver.cpp
index 98008a16..4e279455 100644
--- a/src/engine/HTTPEngineReceiver.cpp
+++ b/src/engine/HTTPEngineReceiver.cpp
@@ -86,20 +86,20 @@ HTTPEngineReceiver::~HTTPEngineReceiver()
 
 
 void
-HTTPEngineReceiver::activate()
+HTTPEngineReceiver::activate_source()
 {
-	QueuedEventSource::activate();
+	QueuedEventSource::activate_source();
 	_receive_thread->set_name("HTTP Receiver");
 	_receive_thread->start();
 }
 
 
 void
-HTTPEngineReceiver::deactivate()
+HTTPEngineReceiver::deactivate_source()
 {
 	cout << "[HTTPEngineReceiver] Stopped HTTP listening thread" << endl;
 	_receive_thread->stop();
-	QueuedEventSource::deactivate();
+	QueuedEventSource::deactivate_source();
 }
 
 
diff --git a/src/engine/HTTPEngineReceiver.hpp b/src/engine/HTTPEngineReceiver.hpp
index d47e9747..88f71aaf 100644
--- a/src/engine/HTTPEngineReceiver.hpp
+++ b/src/engine/HTTPEngineReceiver.hpp
@@ -31,8 +31,8 @@ public:
 	HTTPEngineReceiver(Engine& engine, uint16_t port);
 	~HTTPEngineReceiver();
 
-	void activate();
-	void deactivate();
+	void activate_source();
+	void deactivate_source();
 
 private:
 	struct ReceiveThread : public Raul::Thread {
diff --git a/src/engine/JackAudioDriver.cpp b/src/engine/JackAudioDriver.cpp
index d7cfece2..f1f814c9 100644
--- a/src/engine/JackAudioDriver.cpp
+++ b/src/engine/JackAudioDriver.cpp
@@ -53,15 +53,7 @@ JackAudioPort::JackAudioPort(JackAudioDriver* driver, DuplexPort* patch_port)
 {
 	assert(patch_port->poly() == 1);
 
-	_jack_port = jack_port_register(_driver->jack_client(),
-		patch_port->path().c_str(), JACK_DEFAULT_AUDIO_TYPE,
-		(patch_port->is_input()) ? JackPortIsInput : JackPortIsOutput,
-		0);
-
-	if (_jack_port == NULL) {
-		cerr << "[JackAudioPort] ERROR: Failed to register port " << patch_port->path() << endl;
-		throw JackAudioDriver::PortRegistrationFailedException();
-	}
+	create();
 
 	patch_port->buffer(0)->clear();
 	patch_port->fixed_buffers(true);
@@ -75,7 +67,22 @@ JackAudioPort::~JackAudioPort()
 
 
 void
-JackAudioPort::unregister()
+JackAudioPort::create()
+{
+	_jack_port = jack_port_register(_driver->jack_client(),
+		_patch_port->path().c_str(), JACK_DEFAULT_AUDIO_TYPE,
+		(_patch_port->is_input()) ? JackPortIsInput : JackPortIsOutput,
+		0);
+
+	if (_jack_port == NULL) {
+		cerr << "[JackAudioPort] ERROR: Failed to register port " << _patch_port->path() << endl;
+		throw JackAudioDriver::PortRegistrationFailedException();
+	}
+}
+
+
+void
+JackAudioPort::destroy()
 {
 	assert(_jack_port);
 	if (jack_port_unregister(_driver->jack_client(), _jack_port))
@@ -103,24 +110,42 @@ JackAudioPort::prepare_buffer(jack_nframes_t nframes)
 	
 //// JackAudioDriver ////
 
-JackAudioDriver::JackAudioDriver(Engine&        engine,
-                                 std::string    server_name,
-                                 std::string    client_name,
-                                 jack_client_t* jack_client)
+JackAudioDriver::JackAudioDriver(Engine& engine)
 	: _engine(engine)
 	, _jack_thread(NULL)
-	, _client(jack_client)
-	, _buffer_size(jack_client ? jack_get_buffer_size(jack_client) : 0)
-	, _sample_rate(jack_client ? jack_get_sample_rate(jack_client) : 0)
+	, _sem(0)
+	, _flag(0)
+	, _client(NULL)
+	, _buffer_size(0)
+	, _sample_rate(0)
 	, _is_activated(false)
-	, _local_client(true) // FIXME
+	, _local_client(true)
 	, _process_context(engine)
 	, _root_patch(NULL)
 {
-	if (!_client) {
+}
+
+
+JackAudioDriver::~JackAudioDriver()
+{
+	deactivate();
+	
+	if (_local_client)
+		jack_client_close(_client);
+}
+
+
+bool
+JackAudioDriver::attach(const std::string& server_name,
+                        const std::string& client_name,
+                        void*              jack_client)
+{
+	assert(!_client);
+	if (!jack_client) {
 		// Try supplied server name
 		if (server_name != "") {
-			_client = jack_client_open(client_name.c_str(), JackServerName, NULL, server_name.c_str());
+			_client = jack_client_open(client_name.c_str(),
+					JackServerName, NULL, server_name.c_str());
 			if (_client)
 				cerr << "[JackAudioDriver] Connected to JACK server '" <<
 					server_name << "'" << endl;
@@ -138,27 +163,27 @@ JackAudioDriver::JackAudioDriver(Engine&        engine,
 		// Still failed
 		if (!_client) {
 			cerr << "[JackAudioDriver] Unable to connect to Jack.  Exiting." << endl;
-			exit(EXIT_FAILURE);
+			return false;
 		}
-
-		_buffer_size = jack_get_buffer_size(_client);
-		_sample_rate = jack_get_sample_rate(_client);
+	} else {
+		_client = (jack_client_t*)jack_client;
 	}
 
+	_local_client = (jack_client == NULL);
+
+	_buffer_size = jack_get_buffer_size(_client);
+	_sample_rate = jack_get_sample_rate(_client);
+	
 	jack_on_shutdown(_client, shutdown_cb, this);
 
 	jack_set_thread_init_callback(_client, thread_init_cb, this);
 	jack_set_sample_rate_callback(_client, sample_rate_cb, this);
 	jack_set_buffer_size_callback(_client, buffer_size_cb, this);
-}
-
-
-JackAudioDriver::~JackAudioDriver()
-{
-	deactivate();
 	
-	if (_local_client)
-		jack_client_close(_client);
+	for (Raul::List<JackAudioPort*>::iterator i = _ports.begin(); i != _ports.end(); ++i)
+		(*i)->create();
+
+	return true;
 }
 
 
@@ -170,6 +195,9 @@ JackAudioDriver::activate()
 		return;
 	}
 
+	if (!_client)
+		attach("", "ingen", NULL);
+
 	jack_set_process_callback(_client, process_cb, this);
 
 	_is_activated = true;
@@ -181,8 +209,11 @@ JackAudioDriver::activate()
 		cout << "[JackAudioDriver] Activated Jack client." << endl;
 	}
 
-	if (!_engine.midi_driver() || dynamic_cast<DummyMidiDriver*>(_engine.midi_driver()))
-		_engine.set_midi_driver(new JackMidiDriver(_engine, _client));
+	if (!_engine.midi_driver() || dynamic_cast<DummyMidiDriver*>(_engine.midi_driver())) {
+		JackMidiDriver* midi_driver = new JackMidiDriver(_engine);
+		midi_driver->attach(*this);
+		_engine.set_midi_driver(midi_driver);
+	}
 }
 
 
@@ -190,12 +221,17 @@ void
 JackAudioDriver::deactivate()
 {
 	if (_is_activated) {
-		for (Raul::List<JackAudioPort*>::iterator i = _ports.begin(); i != _ports.end(); ++i)
-			(*i)->unregister();
+		_flag = 1;
 		_is_activated = false;
+		_sem.wait();
+		for (Raul::List<JackAudioPort*>::iterator i = _ports.begin(); i != _ports.end(); ++i)
+			(*i)->destroy();
 		jack_deactivate(_client);
+		if (_local_client) {
+			jack_client_close(_client);
+			_client = NULL;
+		}
 		_jack_thread->stop();
-		_ports.clear();
 		cout << "[JackAudioDriver] Deactivated Jack client." << endl;
 	}
 }
@@ -288,8 +324,11 @@ JackAudioDriver::driver_port(const Path& path)
 int
 JackAudioDriver::_process_cb(jack_nframes_t nframes) 
 {
-	if (nframes == 0 || ! _is_activated)
+	if (nframes == 0 || ! _is_activated) {
+		if (_flag == 1)
+			_sem.post();
 		return 0;
+	}
 
 	// FIXME: all of this time stuff is screwy
 	
@@ -396,7 +435,9 @@ new_jack_audio_driver(
 		const std::string client_name,
 		void*             jack_client)
 {
-	return new Ingen::JackAudioDriver(engine, server_name, client_name, (jack_client_t*)jack_client);
+	Ingen::JackAudioDriver* driver = new Ingen::JackAudioDriver(engine);
+	driver->attach(server_name, client_name, jack_client);
+	return driver;
 }
 
 }
diff --git a/src/engine/JackAudioDriver.hpp b/src/engine/JackAudioDriver.hpp
index a7f4c2ff..aa952197 100644
--- a/src/engine/JackAudioDriver.hpp
+++ b/src/engine/JackAudioDriver.hpp
@@ -20,8 +20,10 @@
 
 #include <jack/jack.h>
 #include <jack/transport.h>
-#include "raul/Thread.hpp"
+#include "raul/AtomicInt.hpp"
 #include "raul/List.hpp"
+#include "raul/Semaphore.hpp"
+#include "raul/Thread.hpp"
 #include "AudioDriver.hpp"
 #include "Buffer.hpp"
 #include "ProcessContext.hpp"
@@ -48,7 +50,8 @@ public:
 	JackAudioPort(JackAudioDriver* driver, DuplexPort* patch_port);
 	~JackAudioPort();
 	
-	void unregister();
+	void create();
+	void destroy();
 	
 	void set_name(const std::string& name) { jack_port_set_name(_jack_port, name.c_str()); };
 	
@@ -75,13 +78,13 @@ private:
 class JackAudioDriver : public AudioDriver
 {
 public:	
-	JackAudioDriver(Engine&        engine,
-	                std::string    server_name = "default",
-	                std::string    client_name = "ingen",
-	                jack_client_t* jack_client = 0);
-
+	JackAudioDriver(Engine& engine);
 	~JackAudioDriver();
 
+	bool attach(const std::string& server_name,
+	            const std::string& client_name,
+	            void*              jack_client);
+
 	void activate();
 	void deactivate();
 	void enable();
@@ -112,7 +115,7 @@ public:
 	SampleCount    sample_rate()  const { return _sample_rate; }
 	bool           is_activated() const { return _is_activated; }
 	
-	inline SampleCount frame_time() const { return jack_frame_time(_client); }
+	inline SampleCount frame_time() const { return _client ? jack_frame_time(_client) : 0; }
 
 	class PortRegistrationFailedException : public std::exception {};
 
@@ -136,6 +139,8 @@ private:
 
 	Engine&                _engine;
 	Raul::Thread*          _jack_thread;
+	Raul::Semaphore        _sem;
+	Raul::AtomicInt        _flag;
 	jack_client_t*         _client;
 	jack_nframes_t         _buffer_size;
 	jack_nframes_t         _sample_rate;
diff --git a/src/engine/JackMidiDriver.cpp b/src/engine/JackMidiDriver.cpp
index 9551b6be..ec94f962 100644
--- a/src/engine/JackMidiDriver.cpp
+++ b/src/engine/JackMidiDriver.cpp
@@ -47,15 +47,7 @@ JackMidiPort::JackMidiPort(JackMidiDriver* driver, DuplexPort* patch_port)
 {
 	assert(patch_port->poly() == 1);
 
-	_jack_port = jack_port_register(_driver->jack_client(),
-		patch_port->path().c_str(), JACK_DEFAULT_MIDI_TYPE,
-		(patch_port->is_input()) ? JackPortIsInput : JackPortIsOutput,
-		0);
-	
-	if (_jack_port == NULL) {
-		cerr << "[JackMidiPort] ERROR: Failed to register port " << patch_port->path() << endl;
-		throw JackAudioDriver::PortRegistrationFailedException();
-	}
+	create();
 
 	patch_port->buffer(0)->clear();
 }
@@ -68,7 +60,22 @@ JackMidiPort::~JackMidiPort()
 
 
 void
-JackMidiPort::unregister()
+JackMidiPort::create()
+{
+	_jack_port = jack_port_register(_driver->jack_client(),
+		_patch_port->path().c_str(), JACK_DEFAULT_MIDI_TYPE,
+		(_patch_port->is_input()) ? JackPortIsInput : JackPortIsOutput,
+		0);
+	
+	if (_jack_port == NULL) {
+		cerr << "[JackMidiPort] ERROR: Failed to register port " << _patch_port->path() << endl;
+		throw JackAudioDriver::PortRegistrationFailedException();
+	}
+}
+
+
+void
+JackMidiPort::destroy()
 {
 	assert(_jack_port);
 	if (jack_port_unregister(_driver->jack_client(), _jack_port))
@@ -157,9 +164,9 @@ JackMidiPort::post_process(ProcessContext& context)
 bool JackMidiDriver::_midi_thread_exit_flag = true;
 
 
-JackMidiDriver::JackMidiDriver(Engine& engine, jack_client_t* client)
+JackMidiDriver::JackMidiDriver(Engine& engine)
 	: _engine(engine)
-	, _client(client)
+	, _client(NULL)
 	, _is_activated(false)
 	, _is_enabled(false)
 {
@@ -175,6 +182,17 @@ JackMidiDriver::~JackMidiDriver()
 }
 
 
+void
+JackMidiDriver::attach(AudioDriver& driver)
+{
+	JackAudioDriver* jad = dynamic_cast<JackAudioDriver*>(&driver);
+	assert(jad);
+	_client = jad->jack_client();
+	for (Raul::List<JackMidiPort*>::iterator i = _ports.begin(); i != _ports.end(); ++i)
+		(*i)->create();
+}
+
+
 /** Launch and start the MIDI thread.
  */
 void
@@ -190,9 +208,8 @@ void
 JackMidiDriver::deactivate() 
 {
 	for (Raul::List<JackMidiPort*>::iterator i = _ports.begin(); i != _ports.end(); ++i)
-		(*i)->unregister();
+		(*i)->destroy();
 	_is_activated = false;
-	_ports.clear();
 }
 
 
diff --git a/src/engine/JackMidiDriver.hpp b/src/engine/JackMidiDriver.hpp
index af885766..d0e81396 100644
--- a/src/engine/JackMidiDriver.hpp
+++ b/src/engine/JackMidiDriver.hpp
@@ -41,7 +41,8 @@ public:
 	JackMidiPort(JackMidiDriver* driver, DuplexPort* port);
 	virtual ~JackMidiPort();
 
-	void unregister();
+	void create();
+	void destroy();
 
 	void pre_process(ProcessContext& context);
 	void post_process(ProcessContext& context);
@@ -64,9 +65,11 @@ private:
 class JackMidiDriver : public MidiDriver
 {
 public:
-	JackMidiDriver(Engine& engine, jack_client_t* client);
+	JackMidiDriver(Engine& engine);
 	~JackMidiDriver();
 
+	void attach(AudioDriver& driver);
+
 	void activate();
 	void deactivate();
 	void enable()  { _is_enabled = true; }
diff --git a/src/engine/MidiDriver.hpp b/src/engine/MidiDriver.hpp
index 75da9db5..da465293 100644
--- a/src/engine/MidiDriver.hpp
+++ b/src/engine/MidiDriver.hpp
@@ -26,6 +26,7 @@
 namespace Ingen {
 
 class ProcessContext;
+class AudioDriver;
 
 
 /** Midi driver abstract base class.
@@ -37,6 +38,8 @@ class MidiDriver : public Driver
 public:
 	MidiDriver() : Driver(DataType::EVENT) {}
 
+	virtual void attach(AudioDriver& master) {}
+
 	/** Prepare input for the specified (upcoming) cycle.
 	 *
 	 * Realtime safe, run in audio thread before executing the graph for a cycle.
diff --git a/src/engine/OSCEngineReceiver.cpp b/src/engine/OSCEngineReceiver.cpp
index b5505f86..26b8aeeb 100644
--- a/src/engine/OSCEngineReceiver.cpp
+++ b/src/engine/OSCEngineReceiver.cpp
@@ -143,9 +143,9 @@ OSCEngineReceiver::~OSCEngineReceiver()
 
 
 void
-OSCEngineReceiver::activate()
+OSCEngineReceiver::activate_source()
 {
-	QueuedEventSource::activate();
+	QueuedEventSource::activate_source();
 	_receive_thread->set_name("OSC Receiver");
 	_receive_thread->start();
 	_receive_thread->set_scheduling(SCHED_FIFO, 5); // Jack default appears to be 10
@@ -153,11 +153,11 @@ OSCEngineReceiver::activate()
 
 
 void
-OSCEngineReceiver::deactivate()
+OSCEngineReceiver::deactivate_source()
 {
 	cout << "[OSCEngineReceiver] Stopped OSC listening thread" << endl;
 	_receive_thread->stop();
-	QueuedEventSource::deactivate();
+	QueuedEventSource::deactivate_source();
 }
 
 
diff --git a/src/engine/OSCEngineReceiver.hpp b/src/engine/OSCEngineReceiver.hpp
index 75094f55..6ab017d0 100644
--- a/src/engine/OSCEngineReceiver.hpp
+++ b/src/engine/OSCEngineReceiver.hpp
@@ -63,8 +63,8 @@ public:
 	OSCEngineReceiver(Engine& engine, size_t queue_size, uint16_t port);
 	~OSCEngineReceiver();
 
-	void activate();
-	void deactivate();
+	void activate_source();
+	void deactivate_source();
 
 private:
 	struct ReceiveThread : public Raul::Thread {
diff --git a/src/engine/PostProcessor.cpp b/src/engine/PostProcessor.cpp
index b90f7ddc..1595ac38 100644
--- a/src/engine/PostProcessor.cpp
+++ b/src/engine/PostProcessor.cpp
@@ -55,14 +55,18 @@ PostProcessor::process()
 	/* FIXME: process events from all threads if parallel */
 
 	/* Process audio thread generated events */
-	while (_engine.audio_driver()->context().event_sink().read(
-				_event_buffer_size, _event_buffer)) {
-		if (((Event*)_event_buffer)->time() > end_time) {
-			cerr << "WARNING: Lost event with time "
-				<< ((Event*)_event_buffer)->time() << " > " << end_time << endl;
+	while (true) {
+		AudioDriver* driver = _engine.audio_driver();
+		if (driver && driver->context().event_sink().read(_event_buffer_size, _event_buffer)) {
+			if (((Event*)_event_buffer)->time() > end_time) {
+				cerr << "WARNING: Lost event with time "
+					<< ((Event*)_event_buffer)->time() << " > " << end_time << endl;
+				break;
+			}
+			((Event*)_event_buffer)->post_process();
+		} else {
 			break;
 		}
-		((Event*)_event_buffer)->post_process();
 	}
 
 	/* Process normal events */
diff --git a/src/engine/QueuedEngineInterface.cpp b/src/engine/QueuedEngineInterface.cpp
index 6a322e16..9a2cea1b 100644
--- a/src/engine/QueuedEngineInterface.cpp
+++ b/src/engine/QueuedEngineInterface.cpp
@@ -39,8 +39,10 @@ QueuedEngineInterface::now() const
 {
 	// Exactly one cycle latency (some could run ASAP if we get lucky, but not always, and a slight
 	// constant latency is far better than jittery lower (average) latency
-	assert(_engine.audio_driver());
-	return _engine.audio_driver()->frame_time() + _engine.audio_driver()->buffer_size();
+	if (_engine.audio_driver())
+		return _engine.audio_driver()->frame_time() + _engine.audio_driver()->buffer_size();
+	else
+		return 0;
 }
 
 
@@ -99,8 +101,14 @@ QueuedEngineInterface::load_plugins()
 void
 QueuedEngineInterface::activate()
 {
-	QueuedEventSource::activate();
+	static bool in_activate = false;
+	if (!in_activate) {
+		in_activate = true;
+		_engine.activate(1);
+	}
+	QueuedEventSource::activate_source();
 	push_queued(new PingQueuedEvent(_engine, _responder, now()));
+	in_activate = false;
 }
 
 
diff --git a/src/engine/QueuedEventSource.hpp b/src/engine/QueuedEventSource.hpp
index f8ff2783..3054d910 100644
--- a/src/engine/QueuedEventSource.hpp
+++ b/src/engine/QueuedEventSource.hpp
@@ -48,8 +48,8 @@ public:
 	QueuedEventSource(size_t queue_size);
 	~QueuedEventSource();
 
-	void activate()   { Slave::start(); }
-	void deactivate() { Slave::stop(); }
+	void activate_source()   { Slave::start(); }
+	void deactivate_source() { Slave::stop(); }
 
 	void process(PostProcessor& dest, ProcessContext& context);
 	
diff --git a/src/engine/events/ClearPatchEvent.cpp b/src/engine/events/ClearPatchEvent.cpp
index c37d1910..9122281b 100644
--- a/src/engine/events/ClearPatchEvent.cpp
+++ b/src/engine/events/ClearPatchEvent.cpp
@@ -143,7 +143,7 @@ ClearPatchEvent::post_process()
 			for (size_t i = 0; i < _driver_ports->size(); ++i) {
 				Raul::List<DriverPort*>::Node* ln = _driver_ports->at(i);
 				if (ln) {
-					ln->elem()->unregister();
+					ln->elem()->destroy();
 					_engine.maid()->push(ln);
 				}
 			}
diff --git a/src/engine/events/DeactivateEvent.cpp b/src/engine/events/DeactivateEvent.cpp
deleted file mode 100644
index a68419f0..00000000
--- a/src/engine/events/DeactivateEvent.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-/* This file is part of Ingen.
- * Copyright (C) 2007 Dave Robillard <http://drobilla.net>
- * 
- * Ingen is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free Software
- * Foundation; either version 2 of the License, or (at your option) any later
- * version.
- * 
- * Ingen is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
- * 
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include "DeactivateEvent.hpp"
-#include "Responder.hpp"
-#include "Engine.hpp"
-
-namespace Ingen {
-
-
-DeactivateEvent::DeactivateEvent(Engine& engine, SharedPtr<Responder> responder, SampleCount timestamp)
-: QueuedEvent(engine, responder, timestamp)
-{
-}
-
-
-void
-DeactivateEvent::pre_process()
-{
-	QueuedEvent::pre_process();
-}
-
-
-void
-DeactivateEvent::execute(ProcessContext& context)
-{
-	QueuedEvent::execute(context);
-}
-
-
-void
-DeactivateEvent::post_process()
-{
-	_responder->respond_ok();
-	_engine.deactivate();
-}
-
-
-} // namespace Ingen
-
diff --git a/src/engine/events/DeactivateEvent.hpp b/src/engine/events/DeactivateEvent.hpp
index 5a6750ba..eaa7e9cb 100644
--- a/src/engine/events/DeactivateEvent.hpp
+++ b/src/engine/events/DeactivateEvent.hpp
@@ -19,6 +19,7 @@
 #define DEACTIVATEEVENT_H
 
 #include "QueuedEvent.hpp"
+#include "Engine.hpp"
 
 namespace Ingen {
 
@@ -30,11 +31,14 @@ namespace Ingen {
 class DeactivateEvent : public QueuedEvent
 {
 public:
-	DeactivateEvent(Engine& engine, SharedPtr<Responder> responder, SampleCount timestamp);
+	DeactivateEvent(Engine& engine, SharedPtr<Responder> responder, SampleCount timestamp)
+		: QueuedEvent(engine, responder, timestamp)
+	{}
 	
-	void pre_process();
-	void execute(ProcessContext& context);
-	void post_process();
+	void post_process() {
+		_responder->respond_ok();
+		_engine.deactivate();
+	}
 };
 
 
diff --git a/src/engine/events/DestroyEvent.cpp b/src/engine/events/DestroyEvent.cpp
index 52c19945..a9597638 100644
--- a/src/engine/events/DestroyEvent.cpp
+++ b/src/engine/events/DestroyEvent.cpp
@@ -200,7 +200,7 @@ DestroyEvent::post_process()
 	}
 
 	if (_driver_port) {
-		_driver_port->elem()->unregister();
+		_driver_port->elem()->destroy();
 		_engine.maid()->push(_driver_port);
 	}
 }
diff --git a/src/engine/wscript b/src/engine/wscript
index e6f38c0c..66d6f29e 100644
--- a/src/engine/wscript
+++ b/src/engine/wscript
@@ -63,7 +63,6 @@ def build(bld):
 		events/CreateNodeEvent.cpp
 		events/CreatePatchEvent.cpp
 		events/CreatePortEvent.cpp
-		events/DeactivateEvent.cpp
 		events/DestroyEvent.cpp
 		events/DisconnectAllEvent.cpp
 		events/DisconnectionEvent.cpp