For now, only use the multi-threaded process code if we are

using >1 processor for DSP; this involves making the DSP
use setting only take effect on a restart of Ardour.


git-svn-id: svn://localhost/ardour2/branches/3.0@11302 d708f5d6-7413-0410-9779-e7cbd77b26cf

4 files changed, 20 insertions, 38 deletions

diff --git a/libs/ardour/ardour/graph.h b/libs/ardour/ardour/graph.h
index f1ebba698a..b735d69888 100644
--- a/libs/ardour/ardour/graph.h
+++ b/libs/ardour/ardour/graph.h
@@ -94,9 +94,7 @@ protected:
 private:
 	std::list<pthread_t> _thread_list;
 	volatile bool        _quit_threads;
-	PBD::ScopedConnection processor_usage_connection;
 
-	void parameter_changed (std::string);
 	void reset_thread_list ();
 	void drop_threads ();
 
diff --git a/libs/ardour/graph.cc b/libs/ardour/graph.cc
index 5b435884d4..c38106506e 100644
--- a/libs/ardour/graph.cc
+++ b/libs/ardour/graph.cc
@@ -77,28 +77,21 @@ Graph::Graph (Session & session)
 
         reset_thread_list ();
 
-        Config->ParameterChanged.connect_same_thread (processor_usage_connection, boost::bind (&Graph::parameter_changed, this, _1));
-
 #ifdef DEBUG_RT_ALLOC
 	graph = this;
 	pbd_alloc_allowed = &::alloc_allowed;
 #endif
 }
 
-void
-Graph::parameter_changed (std::string param)
-{
-        if (param == X_("processor-usage")) {
-                reset_thread_list ();
-        }
-}
-
 /** Set up threads for running the graph */
 void
 Graph::reset_thread_list ()
 {
         uint32_t num_threads = how_many_dsp_threads ();
 
+	/* For now, we shouldn't be using the graph code if we only have 1 DSP thread */
+	assert (num_threads > 1);
+
         /* don't bother doing anything here if we already have the right
            number of threads.
         */
@@ -114,16 +107,6 @@ Graph::reset_thread_list ()
                 drop_threads ();
         }
 
-#if 0
-        /* XXX this only makes sense when we can use just the AudioEngine thread
-           and still keep the graph current with the route list
-        */
-        if (num_threads <= 1) {
-                /* no point creating 1 thread - the AudioEngine already gives us one
-                 */
-                return;
-        }
-#endif
 	if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::main_thread, this), &a_thread, 100000) == 0) {
 		_thread_list.push_back (a_thread);
 	}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 7ee854dc2d..f2343e1013 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -153,7 +153,6 @@ Session::Session (AudioEngine &eng,
 	, _post_transport_work (0)
 	, _send_timecode_update (false)
 	, _all_route_group (new RouteGroup (*this, "all"))
-	, _process_graph (new Graph (*this))
 	, routes (new RouteList)
 	, _total_free_4k_blocks (0)
 	, _bundles (new BundleList)
@@ -169,6 +168,13 @@ Session::Session (AudioEngine &eng,
 {
 	_locations = new Locations (*this);
 
+	if (how_many_dsp_threads () > 1) {
+		/* For now, only create the graph if we are using >1 DSP threads, as
+		   it is a bit slower than the old code with 1 thread.
+		*/
+		_process_graph.reset (new Graph (*this));
+	}
+
 	playlists.reset (new SessionPlaylists);
 
 	_all_route_group->set_active (true, this);
@@ -1384,8 +1390,6 @@ Session::resort_routes ()
 		/* writer goes out of scope and forces update */
 	}
 
-	//_process_graph->dump(1);
-
 #ifndef NDEBUG
 	boost::shared_ptr<RouteList> rl = routes.reader ();
 	for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
@@ -1460,7 +1464,10 @@ Session::resort_routes_using (boost::shared_ptr<RouteList> r)
 		   Note: the process graph rechain does not require a
 		   topologically-sorted list, but hey ho.
 		*/
-		_process_graph->rechain (sorted_routes, edges);
+		if (_process_graph) {
+			_process_graph->rechain (sorted_routes, edges);
+		}
+		
 		_current_route_graph = edges;
 
 		/* Complete the building of the routes' lists of what directly
@@ -2315,7 +2322,9 @@ Session::remove_route (boost::shared_ptr<Route> route)
 	 */
 
 	resort_routes ();
-	_process_graph->clear_other_chain ();
+	if (_process_graph) {
+		_process_graph->clear_other_chain ();
+	}
 
 	/* get rid of it from the dead wood collection in the route list manager */
 
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 80f922117d..897b58ec8e 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -115,7 +115,7 @@ Session::no_roll (pframes_t nframes)
 		_click_io->silence (nframes);
 	}
 
-	if (1 || _process_graph->threads_in_use() > 0) {
+	if (_process_graph) {
 		DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/no-roll\n");
 		_process_graph->routes_no_roll( nframes, _transport_frame, end_frame, non_realtime_work_pending(), declick);
 	} else {
@@ -155,11 +155,7 @@ Session::process_routes (pframes_t nframes, bool& need_butler)
 	const framepos_t start_frame = _transport_frame;
 	const framepos_t end_frame = _transport_frame + floor (nframes * _transport_speed);
 
-	/* XXX this is hack to force use of the graph even if we are only
-	   using 1 thread. its needed because otherwise when we remove
-	   tracks, the graph never gets updated.
-	*/
-	if (1 || _process_graph->threads_in_use() > 0) {
+	if (_process_graph) {
 		DEBUG_TRACE(DEBUG::ProcessThreads,"calling graph/process-routes\n");
 		_process_graph->process_routes (nframes, start_frame, end_frame, declick, need_butler);
 	} else {
@@ -192,11 +188,7 @@ Session::silent_process_routes (pframes_t nframes, bool& need_butler)
 	const framepos_t start_frame = _transport_frame;
 	const framepos_t end_frame = _transport_frame + lrintf(nframes * _transport_speed);
 
-	/* XXX this is hack to force use of the graph even if we are only
-	   using 1 thread. its needed because otherwise when we remove
-	   tracks, the graph never gets updated.
-	*/
-	if (1 || _process_graph->threads_in_use() > 0) {
+	if (_process_graph) {
 		_process_graph->silent_process_routes (nframes, start_frame, end_frame, need_butler);
 	} else {
 		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {