Initialize uninitialized variable

[ardour.git] / libs / ardour / graphnode.cc

diff --git a/libs/ardour/graphnode.cc b/libs/ardour/graphnode.cc
index 72b64abae0305d827f0c30b463a231f71cf98e53..7115b931d8bd2584989d9d637ad81cd229233dfa 100644 (file)
--- a/libs/ardour/graphnode.cc
+++ b/libs/ardour/graphnode.cc
@@ -1,22 +1,22 @@
 /*
-  Copyright (C) 2010 Paul Davis
-  Author: Torben Hohn
-
-  This program 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.
-
-  This program 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 more 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., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-*/
+ * Copyright (C) 2010-2011 David Robillard <d@drobilla.net>
+ * Copyright (C) 2011 Carl Hetherington <carl@carlh.net>
+ * Copyright (C) 2017-2019 Robin Gareus <robin@gareus.org>
+ *
+ * This program 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.
+ *
+ * This program 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 more 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
 
 #include "ardour/graph.h"
 #include "ardour/graphnode.h"
@@ -25,47 +25,57 @@
 using namespace ARDOUR;
 
 GraphNode::GraphNode (boost::shared_ptr<Graph> graph)
-        : _graph(graph)
+       : _graph (graph)
 {
 }
 
-GraphNode::~GraphNode()
+GraphNode::~GraphNode ()
 {
 }
 
 void
 GraphNode::prep (int chain)
 {
-        _refcount = _init_refcount[chain];
+       /* This is the number of nodes that directly feed us */
+       g_atomic_int_set (&_refcount, _init_refcount[chain]);
 }
 
+/** Called by an upstream node, when it has completed processing */
 void
-GraphNode::dec_ref()
+GraphNode::trigger ()
 {
-        if (g_atomic_int_dec_and_test (&_refcount))
-                _graph->trigger (this);
+       /* check if we can run */
+       if (g_atomic_int_dec_and_test (&_refcount)) {
+#if 0 // TODO optimize: remove prep()
+               /* reset reference count for next cycle */
+               g_atomic_int_set (&_refcount, _init_refcount[chain]);
+#endif
+               /* All nodes that feed this node have completed, so this node be processed now. */
+               _graph->trigger (this);
+       }
 }
 
 void
 GraphNode::finish (int chain)
 {
-        node_set_t::iterator i;
-        bool feeds_somebody = false;
+       node_set_t::iterator i;
+       bool                 feeds = false;
 
-        for (i=_activation_set[chain].begin(); i!=_activation_set[chain].end(); i++) {
-                (*i)->dec_ref();
-                feeds_somebody = true;
-        }
+       /* Notify downstream nodes that depend on this node */
+       for (i = _activation_set[chain].begin (); i != _activation_set[chain].end (); ++i) {
+               (*i)->trigger ();
+               feeds = true;
+       }
 
-        if (!feeds_somebody) {
-               /* This node does not feed anybody, so decrement the graph's finished count */
-                _graph->dec_ref();
-        }
+       if (!feeds) {
+               /* This node is a terminal node that does not feed another note,
+                * so notify the graph to decrement the the finished count */
+               _graph->reached_terminal_node ();
+       }
 }
 
-
 void
-GraphNode::process()
+GraphNode::process ()
 {
-        _graph->process_one_route (dynamic_cast<Route *>(this));
+       _graph->process_one_route (dynamic_cast<Route*> (this));
 }