redesign cross-thread registration/signalling system

This new design will work even when threads that need to receive
messages from RT threads are created *after* the RT threads. The
existing design would fail because the RT thread(s) would never
be known the later created threads, and so signals emitted by the
RT thread and causing call_slot() in the receiver would end up
being enqueued using a lock-protected list. The new design ensures
that communication always uses a lock-free FIFO instead

1 files changed, 5 insertions, 7 deletions

diff --git a/libs/pbd/pbd/abstract_ui.h b/libs/pbd/pbd/abstract_ui.h
index 5491210db7..78a337fc40 100644
--- a/libs/pbd/pbd/abstract_ui.h
+++ b/libs/pbd/pbd/abstract_ui.h
@@ -58,20 +58,20 @@ class ABSTRACT_UI_API AbstractUI : public BaseUI
 	AbstractUI (const std::string& name);
 	virtual ~AbstractUI() {}
 
-	void register_thread (std::string, pthread_t, std::string, uint32_t num_requests);
+	void register_thread (pthread_t, std::string, uint32_t num_requests);
 	void call_slot (EventLoop::InvalidationRecord*, const boost::function<void()>&);
         Glib::Threads::Mutex& slot_invalidation_mutex() { return request_buffer_map_lock; }
 
 	Glib::Threads::Mutex request_buffer_map_lock;
 
+	static void* request_buffer_factory (uint32_t num_requests);
+
   protected:
 	struct RequestBuffer : public PBD::RingBufferNPT<RequestObject> {
                 bool dead;
-                AbstractUI<RequestObject>& ui;
-                RequestBuffer (uint32_t size, AbstractUI<RequestObject>& uir)
+                RequestBuffer (uint32_t size)
                         : PBD::RingBufferNPT<RequestObject> (size)
-                        , dead (false)
-                        , ui (uir) {}
+	                , dead (false) {}
         };
 	typedef typename RequestBuffer::rw_vector RequestBufferVector;
 
@@ -105,5 +105,3 @@ class ABSTRACT_UI_API AbstractUI : public BaseUI
 };
 
 #endif /* __pbd_abstract_ui_h__ */
-
-