more fixes for any and all LV2 UI thread schemes

git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@8690 d708f5d6-7413-0410-9779-e7cbd77b26cf

3 files changed, 34 insertions, 13 deletions

diff --git a/gtk2_ardour/lv2_plugin_ui.cc b/gtk2_ardour/lv2_plugin_ui.cc
index de37185198..028f4bec2a 100644
--- a/gtk2_ardour/lv2_plugin_ui.cc
+++ b/gtk2_ardour/lv2_plugin_ui.cc
@@ -42,16 +42,22 @@ LV2PluginUI::lv2_ui_write(LV2UI_Controller controller,
 {
 	LV2PluginUI* me = (LV2PluginUI*)controller;
 
-	cout << "lv2_ui_write, thread registered ? " << me->_thread_registered << endl;
-
-        if (!me->_thread_registered && !Gtkmm2ext::UI::instance()->caller_is_ui_thread()) {
-                cerr << "Registering LV2 external thread " << pthread_self() << endl;
-                PBD::notify_gui_about_thread_creation (pthread_self(), me->_lv2->name());
-                me->_thread_registered = true;
+	cout << "lv2_ui_write, caller = " << pthread_self() << " current registered UI thread " << me->_current_ui_thread << endl;
+
+        if (!Gtkmm2ext::UI::instance()->caller_is_ui_thread()) {
+                if (pthread_self() != me->_current_ui_thread) {
+                        if (me->_current_ui_thread != (pthread_t) 0) {
+                                cerr << "Unregistering LV2 external thread " << me->_current_ui_thread << endl;
+                                PBD::ThreadLeaving (me->_current_ui_thread);
+                        }
+                        cerr << "Registering new LV2 UI external thread " << pthread_self() << endl;
+                        PBD::notify_gui_about_thread_creation (pthread_self(), me->_lv2->name());
+                        me->_current_ui_thread = pthread_self();
+                }
         }
 
 	if (*(float*)buffer != me->_values[port_index]) {
-		cout << "set_parameter " << port_index << ":"  << *(float*)buffer << endl;
+		// cout << "set_parameter " << port_index << ":"  << *(float*)buffer << endl;
 		me->_lv2->set_parameter(port_index, *(float*)buffer);
   }
 }
@@ -135,7 +141,7 @@ LV2PluginUI::output_update()
 LV2PluginUI::LV2PluginUI (boost::shared_ptr<PluginInsert> pi, boost::shared_ptr<LV2Plugin> lv2p)
 	: PlugUIBase (pi)
 	, _lv2(lv2p)
-        , _thread_registered (false)
+        , _current_ui_thread ((pthread_t) 0)
 	, _inst(NULL)
 	, _values(NULL)
 	, _external_ui_ptr(NULL)
diff --git a/gtk2_ardour/lv2_plugin_ui.h b/gtk2_ardour/lv2_plugin_ui.h
index 9400aa6a00..0ad2806537 100644
--- a/gtk2_ardour/lv2_plugin_ui.h
+++ b/gtk2_ardour/lv2_plugin_ui.h
@@ -58,10 +58,10 @@ class LV2PluginUI : public PlugUIBase, public Gtk::VBox
 	boost::shared_ptr<ARDOUR::LV2Plugin> _lv2;
 	std::vector<int> _output_ports;
 	sigc::connection _screen_update_connection;
-	bool             _thread_registered;
-	Gtk::Widget*   _gui_widget;
-	SLV2UIInstance _inst;
-	float*         _values;
+        pthread_t        _current_ui_thread;
+	Gtk::Widget*     _gui_widget;
+	SLV2UIInstance   _inst;
+	float*           _values;
         
 	struct lv2_external_ui_host _external_ui_host;
 	LV2_Feature _external_ui_feature;
diff --git a/libs/pbd/pbd/abstract_ui.cc b/libs/pbd/pbd/abstract_ui.cc
index bc33fc9a39..6ea8d2b940 100644
--- a/libs/pbd/pbd/abstract_ui.cc
+++ b/libs/pbd/pbd/abstract_ui.cc
@@ -1,4 +1,5 @@
 #include <unistd.h>
+#include <cstdlib>
 
 #include <pbd/abstract_ui.h>
 #include <pbd/pthread_utils.h>
@@ -30,10 +31,24 @@ AbstractUI<RequestObject>::register_thread (pthread_t thread_id, string name)
 template <typename RequestObject> void
 AbstractUI<RequestObject>::register_thread_with_request_count (pthread_t thread_id, string thread_name, uint32_t num_requests)
 {
+	RequestBuffer* rbuf = static_cast<RequestBuffer*>(pthread_getspecific (thread_request_buffer_key));
+
+        /* we require that the thread being registered is the caller */
+
+        if (thread_id != pthread_self()) {
+                cerr << "thread attempts to register some other thread with the UI named " << name() << endl;
+                abort ();
+        }
+
+        if (rbuf) {
+                /* this thread is already registered with this AbstractUI */
+                return;
+        }
+
 	RequestBuffer* b = new RequestBuffer (num_requests);
 
 	{
-        Glib::Mutex::Lock lm (request_buffer_map_lock);
+                Glib::Mutex::Lock lm (request_buffer_map_lock);
 		request_buffers[thread_id] = b;
 	}