6 files changed, 45 insertions, 5 deletions
diff --git a/libs/ardour/ardour/control_protocol_manager.h b/libs/ardour/ardour/control_protocol_manager.h
index 0c14d2a049..dbbb0c3891 100644
--- a/libs/ardour/ardour/control_protocol_manager.h
+++ b/libs/ardour/ardour/control_protocol_manager.h
@@ -65,6 +65,7 @@ class LIBARDOUR_API ControlProtocolManager : public PBD::Stateful, public ARDOUR
 	void load_mandatory_protocols ();
 	void midi_connectivity_established ();
 	void drop_protocols ();
+	void register_request_buffer_factories ();
 
 	int activate (ControlProtocolInfo&);
         int deactivate (ControlProtocolInfo&);
diff --git a/libs/ardour/ardour/midi_ui.h b/libs/ardour/ardour/midi_ui.h
index 7f57f22e24..2f0f7d3a45 100644
--- a/libs/ardour/ardour/midi_ui.h
+++ b/libs/ardour/ardour/midi_ui.h
@@ -51,6 +51,7 @@ class LIBARDOUR_API MidiControlUI : public AbstractUI<MidiUIRequest>
 	~MidiControlUI ();
 
 	static MidiControlUI* instance() { return _instance; }
+	static void* request_factory (uint32_t num_requests);
 
 	void change_midi_ports ();
 
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index 3452d1d14c..9c8407e8d7 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -1226,8 +1226,7 @@ AudioEngine::thread_init_callback (void* arg)
 
 	SessionEvent::create_per_thread_pool (X_("AudioEngine"), 512);
 
-	PBD::notify_gui_about_thread_creation ("gui", pthread_self(), X_("AudioEngine"), 4096);
-	PBD::notify_gui_about_thread_creation ("midiUI", pthread_self(), X_("AudioEngine"), 128);
+	PBD::notify_event_loops_about_thread_creation (pthread_self(), X_("AudioEngine"), 4096);
 
 	AsyncMIDIPort::set_process_thread (pthread_self());
 
diff --git a/libs/ardour/control_protocol_manager.cc b/libs/ardour/control_protocol_manager.cc
index 4e2cb7d9f7..6583869fed 100644
--- a/libs/ardour/control_protocol_manager.cc
+++ b/libs/ardour/control_protocol_manager.cc
@@ -22,6 +22,7 @@
 #include <glibmm/fileutils.h>
 
 #include "pbd/compose.h"
+#include "pbd/event_loop.h"
 #include "pbd/file_utils.h"
 #include "pbd/error.h"
 
@@ -487,3 +488,15 @@ ControlProtocolManager::midi_connectivity_established ()
 		(*p)->midi_connectivity_established ();
 	}
 }
+
+void
+ControlProtocolManager::register_request_buffer_factories ()
+{
+	Glib::Threads::Mutex::Lock lm (protocols_lock);
+
+	for (list<ControlProtocolInfo*>::iterator i = control_protocol_info.begin(); i != control_protocol_info.end(); ++i) {
+		if ((*i)->descriptor->request_buffer_factory) {
+			EventLoop::register_request_buffer_factory ((*i)->descriptor->name, (*i)->descriptor->request_buffer_factory);
+		}
+	}
+}
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index b2ad67d053..9f4a1399b3 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -97,6 +97,7 @@
 #include "ardour/event_type_map.h"
 #include "ardour/filesystem_paths.h"
 #include "ardour/midi_region.h"
+#include "ardour/midi_ui.h"
 #include "ardour/midiport_manager.h"
 #include "ardour/mix.h"
 #include "ardour/operations.h"
@@ -513,6 +514,22 @@ ARDOUR::init (bool use_windows_vst, bool try_optimization, const char* localedir
 #endif
 	(void) EventTypeMap::instance();
 
+	ControlProtocolManager::instance().discover_control_protocols ();
+
+	/* for each control protocol, check for a request buffer factory method
+	   and if it exists, store it in the EventLoop list of such
+	   methods. This allows the relevant threads to register themselves
+	   with EventLoops so that signal emission can be RT-safe.
+	*/
+
+	ControlProtocolManager::instance().register_request_buffer_factories ();
+	/* it would be nice if this could auto-register itself in the
+	   constructor, since MidiControlUI is a singleton, but it can't be
+	   created until after the engine is running. Therefore we have to
+	   explicitly register it here.
+	*/
+	EventLoop::register_request_buffer_factory (X_("midiUI"), MidiControlUI::request_factory);
+
         ProcessThread::init ();
 	/* the + 4 is a bit of a handwave. i don't actually know
 	   how many more per-thread buffer sets we need above
@@ -553,8 +570,6 @@ ARDOUR::init (bool use_windows_vst, bool try_optimization, const char* localedir
 void
 ARDOUR::init_post_engine ()
 {
-	ControlProtocolManager::instance().discover_control_protocols ();
-
 	XMLNode* node;
 	if ((node = Config->control_protocol_state()) != 0) {
 		ControlProtocolManager::instance().set_state (*node, Stateful::loading_state_version);
diff --git a/libs/ardour/midi_ui.cc b/libs/ardour/midi_ui.cc
index 96304fa051..1d2fe7c7e1 100644
--- a/libs/ardour/midi_ui.cc
+++ b/libs/ardour/midi_ui.cc
@@ -60,6 +60,17 @@ MidiControlUI::~MidiControlUI ()
 	_instance = 0;
 }
 
+void*
+MidiControlUI::request_factory (uint32_t num_requests)
+{
+	/* AbstractUI<T>::request_buffer_factory() is a template method only
+	   instantiated in this source module. To provide something visible for
+	   use when registering the factory, we have this static method that is
+	   template-free.
+	*/
+	return request_buffer_factory (num_requests);
+}
+
 void
 MidiControlUI::do_request (MidiUIRequest* req)
 {
@@ -131,7 +142,7 @@ MidiControlUI::thread_init ()
 
 	pthread_set_name (X_("midiUI"));
 
-	PBD::notify_gui_about_thread_creation (X_("gui"), pthread_self(), X_("midiUI"), 2048);
+	PBD::notify_event_loops_about_thread_creation (pthread_self(), X_("midiUI"), 2048);
 	SessionEvent::create_per_thread_pool (X_("midiUI"), 128);
 
 	memset (&rtparam, 0, sizeof (rtparam));