MIDI patching fixes (clean disconnecting).

git-svn-id: http://svn.drobilla.net/lad/ingen@416 a436a847-0d15-0410-975c-d299462d15a1

29 files changed, 182 insertions, 82 deletions

diff --git a/src/libs/engine/AudioBuffer.cpp b/src/libs/engine/AudioBuffer.cpp
index 525f0b41..35987942 100644
--- a/src/libs/engine/AudioBuffer.cpp
+++ b/src/libs/engine/AudioBuffer.cpp
@@ -264,7 +264,7 @@ AudioBuffer::is_joined_to(Buffer* buf) const
 
 
 void
-AudioBuffer::prepare(SampleCount nframes)
+AudioBuffer::prepare_read(SampleCount nframes)
 {
 	// FIXME: nframes parameter doesn't actually work,
 	// writing starts from 0 every time
diff --git a/src/libs/engine/AudioBuffer.h b/src/libs/engine/AudioBuffer.h
index fa946108..eba25c83 100644
--- a/src/libs/engine/AudioBuffer.h
+++ b/src/libs/engine/AudioBuffer.h
@@ -52,14 +52,15 @@ public:
 	inline Sample& value_at(size_t offset) const
 		{ assert(offset < _size); return data()[offset]; }
 	
-	void prepare(SampleCount nframes);
+	void prepare_read(SampleCount nframes);
+	void prepare_write(SampleCount nframes) {}
+	
+	void reset(SampleCount nframes) {}
+	void resize(size_t size);
 	
 	void      filled_size(size_t size) { _filled_size = size; }
 	size_t    filled_size() const { return _filled_size; }
-	bool      is_joined()   const { return (_joined_buf == NULL); }
 	size_t    size()        const { return _size; }
-	
-	void resize(size_t size);
 
 private:
 	enum State { OK, HALF_SET_CYCLE_1, HALF_SET_CYCLE_2 };
diff --git a/src/libs/engine/Buffer.h b/src/libs/engine/Buffer.h
index ee94b786..b27c3a86 100644
--- a/src/libs/engine/Buffer.h
+++ b/src/libs/engine/Buffer.h
@@ -37,10 +37,15 @@ public:
 
 	virtual ~Buffer() {}
 	
+	/** Clear contents and reset state */
 	virtual void clear() = 0;
-	virtual void prepare(SampleCount nframes) = 0;
+
+	/** Reset state (ie reset read ptr), but leave contents */
+	virtual void reset(SampleCount nframes) = 0;
+
+	virtual void prepare_read(SampleCount nframes) = 0;
+	virtual void prepare_write(SampleCount nframes) = 0;
 	
-	virtual bool is_joined() const = 0;
 	virtual bool is_joined_to(Buffer* buf) const = 0;
 	virtual bool join(Buffer* buf) = 0;
 	virtual void unjoin() = 0;
diff --git a/src/libs/engine/DSSINode.cpp b/src/libs/engine/DSSINode.cpp
index 5a23baba..58ff050d 100644
--- a/src/libs/engine/DSSINode.cpp
+++ b/src/libs/engine/DSSINode.cpp
@@ -165,7 +165,7 @@ DSSINode::has_midi_input() const
 void
 DSSINode::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	NodeBase::process(nframes, start, end);
+	NodeBase::pre_process(nframes, start, end);
 
 	if (_dssi_descriptor->run_synth) {
 		convert_events();
@@ -181,6 +181,8 @@ DSSINode::process(SampleCount nframes, FrameTime start, FrameTime end)
 	} else {
 		LADSPANode::process(nframes, start, end);
 	}
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/DuplexPort.cpp b/src/libs/engine/DuplexPort.cpp
index f4a71aae..c498c774 100644
--- a/src/libs/engine/DuplexPort.cpp
+++ b/src/libs/engine/DuplexPort.cpp
@@ -40,5 +40,31 @@ DuplexPort::DuplexPort(Node* parent, const string& name, size_t index, size_t po
 }
 
 
+void
+DuplexPort::pre_process(SampleCount nframes, FrameTime start, FrameTime end)
+{
+	if (_is_output) {
+		for (size_t i=0; i < _poly; ++i)
+			_buffers.at(i)->prepare_write(nframes);
+	} else {
+		for (size_t i=0; i < _poly; ++i)
+			_buffers.at(i)->prepare_read(nframes);
+	}
+}
+
+
+void
+DuplexPort::post_process(SampleCount nframes, FrameTime start, FrameTime end)
+{
+	if (_is_output) {
+		for (size_t i=0; i < _poly; ++i)
+			_buffers.at(i)->prepare_read(nframes);
+	} else {
+		for (size_t i=0; i < _poly; ++i)
+			_buffers.at(i)->prepare_write(nframes);
+	}
+}
+
+
 } // namespace Ingen
 
diff --git a/src/libs/engine/DuplexPort.h b/src/libs/engine/DuplexPort.h
index 10c305b4..986c1862 100644
--- a/src/libs/engine/DuplexPort.h
+++ b/src/libs/engine/DuplexPort.h
@@ -45,10 +45,11 @@ public:
 	DuplexPort(Node* parent, const string& name, size_t index, size_t poly, DataType type, size_t buffer_size, bool is_output);
 	virtual ~DuplexPort() {}
 
-	virtual void prepare_buffers(size_t nframes) {}
+	void pre_process(SampleCount nframes, FrameTime start, FrameTime end);
+	void post_process(SampleCount nframes, FrameTime start, FrameTime end);
 	
-	virtual bool is_input()  const { return !_is_output; }
-	virtual bool is_output() const { return _is_output; }
+	bool is_input()  const { return !_is_output; }
+	bool is_output() const { return _is_output; }
 
 protected:
 	bool _is_output;
diff --git a/src/libs/engine/Engine.cpp b/src/libs/engine/Engine.cpp
index 053528ff..ddb9ea81 100644
--- a/src/libs/engine/Engine.cpp
+++ b/src/libs/engine/Engine.cpp
@@ -190,9 +190,6 @@ Engine::deactivate()
 {
 	if (!_activated)
 		return;
-	
-	_audio_driver->root_patch()->disable();
-	_audio_driver->root_patch()->deactivate();
 
 	/*for (Tree<GraphObject*>::iterator i = _object_store->objects().begin();
 			i != _object_store->objects().end(); ++i)
@@ -204,6 +201,8 @@ Engine::deactivate()
 	
 	_audio_driver->deactivate();
 
+	_audio_driver->root_patch()->deactivate();
+
 	// Finalize any lingering events (unlikely)
 	_post_processor->whip();
 	_post_processor->stop();
diff --git a/src/libs/engine/InputPort.cpp b/src/libs/engine/InputPort.cpp
index 9326afd6..0e149abe 100644
--- a/src/libs/engine/InputPort.cpp
+++ b/src/libs/engine/InputPort.cpp
@@ -102,7 +102,7 @@ InputPort::remove_connection(const OutputPort* src_port)
 		if (_connections.size() == 0) {
 			for (size_t i=0; i < _poly; ++i) {
 				// Use a local buffer
-				if (modify_buffers && _buffers.at(i)->is_joined())
+				if (modify_buffers)
 					_buffers.at(i)->unjoin();
 				_buffers.at(i)->clear(); // Write silence
 				//if (_is_tied)
@@ -145,10 +145,8 @@ InputPort::is_connected_to(const OutputPort* port) const
  *  FIXME: nframes parameter not used,
  */
 void
-InputPort::process(SampleCount nframes, FrameTime start, FrameTime end)
+InputPort::pre_process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	Port::process(nframes, start, end);
-
 	//assert(!_is_tied || _tied_port != NULL);
 
 	bool do_mixdown = true;
@@ -167,7 +165,6 @@ InputPort::process(SampleCount nframes, FrameTime start, FrameTime end)
 				do_mixdown = true;
 			} else {
 				// zero-copy
-				//assert(_buffers.at(0)->is_joined());
 				_buffers.at(0)->join((*_connections.begin())->buffer(0));
 				do_mixdown = false;
 			}
@@ -179,6 +176,9 @@ InputPort::process(SampleCount nframes, FrameTime start, FrameTime end)
 
 	//cerr << path() << " mixing: " << do_mixdown << endl;
 
+	for (size_t i=0; i < _poly; ++i)
+		_buffers.at(i)->prepare_read(nframes);
+
 	if (!do_mixdown) {
 		assert(_buffers.at(0)->is_joined_to((*_connections.begin())->buffer(0)));
 		return;
@@ -188,6 +188,7 @@ InputPort::process(SampleCount nframes, FrameTime start, FrameTime end)
 	assert(!_is_tied || _buffers.at(0)->data() == _tied_port->buffer(0)->data());*/
 
 	for (size_t voice=0; voice < _poly; ++voice) {
+		assert(_type == DataType::FLOAT);
 		// Copy first connection
 		((AudioBuffer*)_buffers.at(voice))->copy(
 			((AudioBuffer*)(*_connections.begin())->buffer(voice)), 0, _buffer_size-1);
diff --git a/src/libs/engine/InputPort.h b/src/libs/engine/InputPort.h
index 284f976f..25777ecf 100644
--- a/src/libs/engine/InputPort.h
+++ b/src/libs/engine/InputPort.h
@@ -56,7 +56,7 @@ public:
 	typedef Raul::List<Connection*> Connections;
 	const Connections& connections() { return _connections; }
 
-	void process(SampleCount nframes, FrameTime start, FrameTime end);
+	void pre_process(SampleCount nframes, FrameTime start, FrameTime end);
 	
 	bool is_connected() const { return (_connections.size() > 0); }
 	bool is_connected_to(const OutputPort* port) const;
diff --git a/src/libs/engine/InternalNode.h b/src/libs/engine/InternalNode.h
index b3ad00a3..7f7d54fe 100644
--- a/src/libs/engine/InternalNode.h
+++ b/src/libs/engine/InternalNode.h
@@ -42,9 +42,6 @@ public:
 	
 	virtual ~InternalNode() {}
 
-	virtual void process(SampleCount nframes, FrameTime start, FrameTime end)
-		{ NodeBase::process(nframes, start, end); }
-
 protected:
 	Plugin* plugin() const { return const_cast<Plugin*>(_plugin); }
 };
diff --git a/src/libs/engine/JackMidiDriver.cpp b/src/libs/engine/JackMidiDriver.cpp
index ada9a439..44c44725 100644
--- a/src/libs/engine/JackMidiDriver.cpp
+++ b/src/libs/engine/JackMidiDriver.cpp
@@ -80,8 +80,7 @@ JackMidiPort::prepare_block(const SampleCount block_start, const SampleCount blo
 	MidiBuffer* patch_buf = dynamic_cast<MidiBuffer*>(_patch_port->buffer(0));
 	assert(patch_buf);
 
-	patch_buf->clear();
-	patch_buf->reset_state(nframes);
+	patch_buf->prepare_write(nframes);
 	
 	// Copy events from Jack port buffer into patch port buffer
 	for (jack_nframes_t i=0; i < event_count; ++i) {
diff --git a/src/libs/engine/LADSPANode.cpp b/src/libs/engine/LADSPANode.cpp
index 3ad197a4..b347afa6 100644
--- a/src/libs/engine/LADSPANode.cpp
+++ b/src/libs/engine/LADSPANode.cpp
@@ -176,9 +176,12 @@ LADSPANode::deactivate()
 void
 LADSPANode::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	NodeBase::process(nframes, start, end); // mixes down input ports
+	NodeBase::pre_process(nframes, start, end);
+
 	for (size_t i=0; i < _poly; ++i) 
 		_descriptor->run(_instances[i], nframes);
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/LV2Node.cpp b/src/libs/engine/LV2Node.cpp
index 0baf41ef..f05a477b 100644
--- a/src/libs/engine/LV2Node.cpp
+++ b/src/libs/engine/LV2Node.cpp
@@ -170,9 +170,12 @@ LV2Node::deactivate()
 void
 LV2Node::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	NodeBase::process(nframes, start, end); // mixes down input ports
+	NodeBase::pre_process(nframes, start, end);
+
 	for (size_t i=0; i < _poly; ++i) 
 		slv2_instance_run(_instances[i], nframes);
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/Makefile.am b/src/libs/engine/Makefile.am
index 29b601a9..2516b24a 100644
--- a/src/libs/engine/Makefile.am
+++ b/src/libs/engine/Makefile.am
@@ -48,6 +48,7 @@ libingen_la_SOURCES = \
 	InputPort.h \
 	InputPort.cpp \
 	OutputPort.h \
+	OutputPort.cpp \
 	DuplexPort.h \
 	DuplexPort.cpp \
 	MidiMessage.h \
diff --git a/src/libs/engine/MidiBuffer.cpp b/src/libs/engine/MidiBuffer.cpp
index 7dfe72e6..35bda0a0 100644
--- a/src/libs/engine/MidiBuffer.cpp
+++ b/src/libs/engine/MidiBuffer.cpp
@@ -15,8 +15,11 @@
  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+//#include <iostream>
 #include "MidiBuffer.h"
 
+using namespace std;
+
 namespace Ingen {
 
 
@@ -48,6 +51,8 @@ MidiBuffer::unjoin()
 	_joined_buf = NULL;
 	_buf   = _local_buf;
 	_state = &_local_state;
+	clear();
+	reset(_this_nframes);
 }
 
 
@@ -63,14 +68,23 @@ MidiBuffer::is_joined_to(Buffer* buf) const
 
 
 void
-MidiBuffer::prepare(SampleCount nframes)
+MidiBuffer::prepare_read(SampleCount nframes)
+{
+	assert(!_joined_buf || data() == _joined_buf->data());
+	assert(!_joined_buf || state() == _joined_buf->state());
+	
+	reset(nframes);
+}
+
+
+void
+MidiBuffer::prepare_write(SampleCount nframes)
 {
-	if (_joined_buf)
-		_local_state = *_joined_buf->state();
-	else
-		reset_state(nframes);
+	clear();
+	reset(nframes);
 
-	_this_nframes = nframes;
+	assert(!_joined_buf || data() == _joined_buf->data());
+	assert(!_joined_buf || state() == _joined_buf->state());
 }
 
 
diff --git a/src/libs/engine/MidiBuffer.h b/src/libs/engine/MidiBuffer.h
index 459c1209..5a810bc3 100644
--- a/src/libs/engine/MidiBuffer.h
+++ b/src/libs/engine/MidiBuffer.h
@@ -31,20 +31,19 @@ public:
 	MidiBuffer(size_t capacity)
 		: Buffer(DataType(DataType::MIDI), capacity)
 		, _state(&_local_state)
-		, _buf(lv2midi_new((uint32_t)capacity))
-		, _local_buf(NULL)
+		, _local_buf(lv2midi_new((uint32_t)capacity))
+		, _buf(_local_buf)
 		, _joined_buf(NULL)
 	{
 		clear();
-		reset_state(0);
 	}
 
 	~MidiBuffer() { lv2midi_free(_buf); }
 
-	void prepare(SampleCount nframes);
+	void prepare_read(SampleCount nframes);
+	void prepare_write(SampleCount nframes);
 
 	bool is_joined_to(Buffer* buf) const;
-	bool is_joined() const { return (_joined_buf == NULL); }
 	bool join(Buffer* buf);
 	void unjoin();
 
@@ -57,9 +56,9 @@ public:
 		{ return ((_joined_buf != NULL) ? _joined_buf->state() : _state); }
 
 	inline void clear()
-		{ lv2midi_reset_buffer(_buf); }
+		{ lv2midi_reset_buffer(_buf); _state->position = 0; }
 
-	inline void reset_state(uint32_t nframes)
+	inline void reset(SampleCount nframes)
 		{ lv2midi_reset_state(_state, _buf, nframes); _this_nframes = nframes; }
 
 	inline double increment()
@@ -72,10 +71,10 @@ public:
 		{ return lv2midi_put_event(_state, timestamp, size, data); }
 
 private:
-	LV2_MIDIState* _state;
 	LV2_MIDIState  _local_state;
-	LV2_MIDI*      _buf;
+	LV2_MIDIState* _state;
 	LV2_MIDI*      _local_buf;
+	LV2_MIDI*      _buf;
 	
 	MidiBuffer* _joined_buf;  ///< Buffer to mirror, if joined
 
diff --git a/src/libs/engine/MidiControlNode.cpp b/src/libs/engine/MidiControlNode.cpp
index 81df8e6c..abe930c8 100644
--- a/src/libs/engine/MidiControlNode.cpp
+++ b/src/libs/engine/MidiControlNode.cpp
@@ -65,7 +65,7 @@ MidiControlNode::MidiControlNode(const string& path, size_t poly, Patch* parent,
 void
 MidiControlNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	InternalNode::process(nframes, start, end);
+	NodeBase::pre_process(nframes, start, end);
 	
 	double         timestamp = 0;
 	uint32_t       size = 0;
@@ -81,6 +81,8 @@ MidiControlNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 		if (size >= 3 && (buffer[0] & 0xF0) == MIDI_CMD_CONTROL)
 			control(buffer[1], buffer[2], time);
 	}
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/MidiNoteNode.cpp b/src/libs/engine/MidiNoteNode.cpp
index 6a6b698c..aac195ef 100644
--- a/src/libs/engine/MidiNoteNode.cpp
+++ b/src/libs/engine/MidiNoteNode.cpp
@@ -75,7 +75,7 @@ MidiNoteNode::~MidiNoteNode()
 void
 MidiNoteNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	InternalNode::process(nframes, start, end);
+	NodeBase::pre_process(nframes, start, end);
 	
 	double         timestamp = 0;
 	uint32_t       size = 0;
@@ -122,6 +122,8 @@ MidiNoteNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 
 		midi_in->increment();
 	}
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/MidiTriggerNode.cpp b/src/libs/engine/MidiTriggerNode.cpp
index 9d78f7b8..d45cfe85 100644
--- a/src/libs/engine/MidiTriggerNode.cpp
+++ b/src/libs/engine/MidiTriggerNode.cpp
@@ -60,7 +60,7 @@ MidiTriggerNode::MidiTriggerNode(const string& path, size_t poly, Patch* parent,
 void
 MidiTriggerNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	InternalNode::process(nframes, start, end);
+	NodeBase::pre_process(nframes, start, end);
 	
 	double         timestamp = 0;
 	uint32_t       size = 0;
@@ -93,6 +93,8 @@ MidiTriggerNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 			}
 		}
 	}
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/NodeBase.cpp b/src/libs/engine/NodeBase.cpp
index 7f9fe23b..ffd509c4 100644
--- a/src/libs/engine/NodeBase.cpp
+++ b/src/libs/engine/NodeBase.cpp
@@ -123,18 +123,31 @@ NodeBase::set_buffer_size(size_t size)
 }
 
 
-/** Runs the Node for the specified number of frames (block size)
+/** Prepare to run a cycle (in the audio thread)
  */
 void
-NodeBase::process(SampleCount nframes, FrameTime start, FrameTime end)
+NodeBase::pre_process(SampleCount nframes, FrameTime start, FrameTime end)
 {
 	assert(_activated);
 	// Mix down any ports with multiple inputs
 	for (size_t i=0; i < _ports->size(); ++i)
-		_ports->at(i)->process(nframes, start, end);
+		_ports->at(i)->pre_process(nframes, start, end);
 }
 
 
+/** Prepare to run a cycle (in the audio thread)
+ */
+void
+NodeBase::post_process(SampleCount nframes, FrameTime start, FrameTime end)
+{
+	assert(_activated);
+	// Prepare any output ports for reading (MIDI)
+	for (size_t i=0; i < _ports->size(); ++i)
+		_ports->at(i)->post_process(nframes, start, end);
+}
+
+
+
 /** Rename this Node.
  *
  * This is responsible for updating the ObjectStore so the Node can be
diff --git a/src/libs/engine/NodeBase.h b/src/libs/engine/NodeBase.h
index 8fed6196..6ae890f3 100644
--- a/src/libs/engine/NodeBase.h
+++ b/src/libs/engine/NodeBase.h
@@ -53,7 +53,9 @@ public:
 	virtual void deactivate();
 	bool activated() { return _activated; }
 
-	virtual void process(SampleCount nframes, FrameTime start, FrameTime end);
+	virtual void post_process(SampleCount nframes, FrameTime start, FrameTime end);
+	virtual void process(SampleCount nframes, FrameTime start, FrameTime end) = 0;
+	virtual void pre_process(SampleCount nframes, FrameTime start, FrameTime end);
 		
 	virtual void set_port_buffer(size_t voice, size_t port_num, Buffer* buf) {}
 	
diff --git a/src/libs/engine/OutputPort.cpp b/src/libs/engine/OutputPort.cpp
new file mode 100644
index 00000000..ea723963
--- /dev/null
+++ b/src/libs/engine/OutputPort.cpp
@@ -0,0 +1,40 @@
+/* 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 "OutputPort.h"
+#include "Buffer.h"
+
+namespace Ingen {
+
+
+void
+OutputPort::pre_process(SampleCount nframes, FrameTime start, FrameTime end)
+{
+	for (size_t i=0; i < _poly; ++i)
+		_buffers.at(i)->prepare_write(nframes);
+}
+
+
+void
+OutputPort::post_process(SampleCount nframes, FrameTime start, FrameTime end)
+{
+	for (size_t i=0; i < _poly; ++i)
+		_buffers.at(i)->prepare_read(nframes);
+}
+
+
+} // namespace Ingen
diff --git a/src/libs/engine/OutputPort.h b/src/libs/engine/OutputPort.h
index 10118076..0e94be9f 100644
--- a/src/libs/engine/OutputPort.h
+++ b/src/libs/engine/OutputPort.h
@@ -49,6 +49,9 @@ public:
 	: Port(parent, name, index, poly, type, buffer_size)
 	{}
 
+	void pre_process(SampleCount nframes, FrameTime start, FrameTime end);
+	void post_process(SampleCount nframes, FrameTime start, FrameTime end);
+	
 	virtual ~OutputPort() {}
 
 	bool is_input()  const { return false; }
diff --git a/src/libs/engine/Patch.cpp b/src/libs/engine/Patch.cpp
index a2b5a85f..ad414642 100644
--- a/src/libs/engine/Patch.cpp
+++ b/src/libs/engine/Patch.cpp
@@ -98,15 +98,10 @@ Patch::deactivate()
 void
 Patch::disable()
 {
-	// Write output buffers to 0
-	/*for (Raul::List<InternalNode*>::iterator i = _bridge_nodes.begin(); i != _bridge_nodes.end(); ++i) {
-	  assert((*i)->as_port() != NULL);
-	  if ((*i)->as_port()->port_info()->is_output())
-	  (*i)->as_port()->clear_buffers();*/
+	_process = false;
+
 	for (Raul::List<Port*>::iterator i = _output_ports.begin(); i != _output_ports.end(); ++i)
 		(*i)->clear_buffers();
-
-	_process = false;
 }
 
 
diff --git a/src/libs/engine/Patch.h b/src/libs/engine/Patch.h
index 55a2be83..76290c8f 100644
--- a/src/libs/engine/Patch.h
+++ b/src/libs/engine/Patch.h
@@ -98,21 +98,21 @@ public:
 	
 	/** Whether to run this patch's DSP bits in the audio thread */
 	bool enabled() const { return _process; }
-	void enable()        { _process = true; }
+	void enable() { _process = true; }
 	void disable();
 
 	size_t internal_poly() const { return _internal_poly; }
 
 private:
-	inline void   build_process_order_recursive(Node* n, Raul::Array<Node*>* order) const;
-
-	size_t             _internal_poly;
-	Raul::Array<Node*>*      _process_order; ///< Accessed in audio thread only
-	Raul::List<Connection*>  _connections;   ///< Accessed in audio thread only
-	Raul::List<Port*>        _input_ports;   ///< Accessed in preprocessing thread only
-	Raul::List<Port*>        _output_ports;  ///< Accessed in preprocessing thread only
-	Raul::List<Node*>        _nodes;         ///< Accessed in preprocessing thread only
-	bool               _process;
+	inline void build_process_order_recursive(Node* n, Raul::Array<Node*>* order) const;
+
+	size_t                  _internal_poly;
+	Raul::Array<Node*>*     _process_order; ///< Accessed in audio thread only
+	Raul::List<Connection*> _connections;   ///< Accessed in audio thread only
+	Raul::List<Port*>       _input_ports;   ///< Accessed in preprocessing thread only
+	Raul::List<Port*>       _output_ports;  ///< Accessed in preprocessing thread only
+	Raul::List<Node*>       _nodes;         ///< Accessed in preprocessing thread only
+	bool                    _process;
 };
 
 
diff --git a/src/libs/engine/Port.cpp b/src/libs/engine/Port.cpp
index 4b9a014b..bfb09a35 100644
--- a/src/libs/engine/Port.cpp
+++ b/src/libs/engine/Port.cpp
@@ -91,12 +91,4 @@ Port::clear_buffers()
 }
 
 
-void
-Port::process(SampleCount nframes, FrameTime start, FrameTime end)
-{
-	for (size_t i=0; i < _poly; ++i)
-		_buffers.at(i)->prepare(nframes);
-}
-
-
 } // namespace Ingen
diff --git a/src/libs/engine/Port.h b/src/libs/engine/Port.h
index b42231fe..6b3c20e8 100644
--- a/src/libs/engine/Port.h
+++ b/src/libs/engine/Port.h
@@ -52,7 +52,9 @@ public:
 	Buffer* buffer(size_t voice) const { return _buffers.at(voice); }
 
 	/** Called once per process cycle */
-	virtual void process(SampleCount nframes, FrameTime start, FrameTime end);
+	virtual void pre_process(SampleCount nframes, FrameTime start, FrameTime end) = 0;
+	virtual void process(SampleCount nframes, FrameTime start, FrameTime end) {}
+	virtual void post_process(SampleCount nframes, FrameTime start, FrameTime end) {};
 	
 	/** Empty buffer contents completely (ie silence) */
 	virtual void clear_buffers();
diff --git a/src/libs/engine/TransportNode.cpp b/src/libs/engine/TransportNode.cpp
index 028fd45e..d8895d72 100644
--- a/src/libs/engine/TransportNode.cpp
+++ b/src/libs/engine/TransportNode.cpp
@@ -83,7 +83,7 @@ TransportNode::TransportNode(const string& path, size_t poly, Patch* parent, Sam
 void
 TransportNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 {
-	NodeBase::process(nframes, start, end);
+	NodeBase::pre_process(nframes, start, end);
 #if 0
 
 	// FIXME: this will die horribly with any driver other than jack (in theory)
@@ -147,6 +147,8 @@ TransportNode::process(SampleCount nframes, FrameTime start, FrameTime end)
 		}
 	}
 	#endif
+	
+	NodeBase::post_process(nframes, start, end);
 }
 
 
diff --git a/src/libs/engine/events/DisconnectionEvent.cpp b/src/libs/engine/events/DisconnectionEvent.cpp
index aef271f4..7ac7e236 100644
--- a/src/libs/engine/events/DisconnectionEvent.cpp
+++ b/src/libs/engine/events/DisconnectionEvent.cpp
@@ -92,12 +92,6 @@ DisconnectionEvent::pre_process()
 		return;
 	}
 
-	if (_src_port->type() != _dst_port->type() || _src_port->buffer_size() != _dst_port->buffer_size()) {
-		_error = TYPE_MISMATCH;
-		QueuedEvent::pre_process();
-		return;
-	}
-
 	_dst_input_port = dynamic_cast<InputPort*>(_dst_port);
 	_src_output_port = dynamic_cast<OutputPort*>(_src_port);
 	assert(_src_output_port);