X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=nodestack.cc;h=d3b7c104316161d0268c8ae1b2db7a116fbbac74;hb=a59176e8094c3a7ec272f70b7f9511f9061dd117;hp=c9878a339ec384febedaa95385e31cac478cc169;hpb=eb8e9f61a400856421465d95ac52d9cffed2a491;p=c11tester.git

diff --git a/nodestack.cc b/nodestack.cc
index c9878a33..d3b7c104 100644
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -3,13 +3,31 @@
 #include "common.h"
 #include "model.h"
 
-/** @brief Node constructor */
-Node::Node(ModelAction *act, int nthreads)
+/**
+ * @brief Node constructor
+ *
+ * Constructs a single Node for use in a NodeStack. Each Node is associated
+ * with exactly one ModelAction (exception: the first Node should be created
+ * as an empty stub, to represent the first thread "choice") and up to one
+ * parent.
+ *
+ * @param act The ModelAction to associate with this Node. May be NULL.
+ * @param par The parent Node in the NodeStack. May be NULL if there is no
+ * parent.
+ * @param nthreads The number of threads which exist at this point in the
+ * execution trace.
+ */
+Node::Node(ModelAction *act, Node *par, int nthreads)
 	: action(act),
+	parent(par),
 	num_threads(nthreads),
 	explored_children(num_threads),
-	backtrack(num_threads)
+	backtrack(num_threads),
+	numBacktracks(0),
+	may_read_from()
 {
+	if (act)
+		act->set_node(this);
 }
 
 /** @brief Node desctructor */
@@ -47,22 +65,15 @@ bool Node::has_been_explored(thread_id_t tid)
  */
 bool Node::backtrack_empty()
 {
-	unsigned int i;
-	for (i = 0; i < backtrack.size(); i++)
-		if (backtrack[i] == true)
-			return false;
-	return true;
+	return numBacktracks == 0;
 }
 
 /**
- * Explore a child Node using a given ModelAction. This updates both the
- * Node-internal and the ModelAction data to associate the ModelAction with
- * this Node.
- * @param act is the ModelAction to explore
+ * Mark the appropriate backtracking infromation for exploring a thread choice.
+ * @param act The ModelAction to explore
  */
 void Node::explore_child(ModelAction *act)
 {
-	act->set_node(this);
 	explore(act->get_tid());
 }
 
@@ -79,6 +90,7 @@ bool Node::set_backtrack(thread_id_t id)
 	if (backtrack[i])
 		return false;
 	backtrack[i] = true;
+	numBacktracks++;
 	return true;
 }
 
@@ -92,6 +104,7 @@ thread_id_t Node::get_next_backtrack()
 	if (i >= backtrack.size())
 		return THREAD_ID_T_NONE;
 	backtrack[i] = false;
+	numBacktracks--;
 	return int_to_id(i);
 }
 
@@ -100,10 +113,22 @@ bool Node::is_enabled(Thread *t)
 	return id_to_int(t->get_id()) < num_threads;
 }
 
+/**
+ * Add an action to the may_read_from set.
+ * @param act is the action to add
+ */
+void Node::add_read_from(ModelAction *act)
+{
+	may_read_from.insert(act);
+}
+
 void Node::explore(thread_id_t tid)
 {
 	int i = id_to_int(tid);
-	backtrack[i] = false;
+	if (backtrack[i]) {
+		backtrack[i] = false;
+		numBacktracks--;
+	}
 	explored_children[i] = true;
 }
 
@@ -161,7 +186,7 @@ ModelAction * NodeStack::explore_action(ModelAction *act)
 
 	/* Record action */
 	get_head()->explore_child(act);
-	node_list.push_back(new Node(act, model->get_num_threads()));
+	node_list.push_back(new Node(act, get_head(), model->get_num_threads()));
 	total_nodes++;
 	iter++;
 	return NULL;