X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;ds=sidebyside;f=nodestack.cc;h=2416ed7c5b35d23deadd2f2681cd890a926e7f98;hb=9603efba5f5006b21140286138ba7e003d29e997;hp=87b3ee531fbe2d10a7b52f229f23e7ea90196e9d;hpb=f3ef22bef8d339c7d45b7d7232cdcf183a0b7776;p=model-checker.git

diff --git a/nodestack.cc b/nodestack.cc
index 87b3ee5..2416ed7 100644
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -3,15 +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),
 	numBacktracks(0),
 	may_read_from()
 {
+	if (act)
+		act->set_node(this);
 }
 
 /** @brief Node desctructor */
@@ -30,6 +46,14 @@ void Node::print()
 		printf("******** empty action ********\n");
 }
 
+/** @brief Prints info about may_read_from set */
+void Node::print_may_read_from()
+{
+	readfrom_set_t::iterator it;
+	for (it = may_read_from.begin(); it != may_read_from.end(); it++)
+		(*it)->print();
+}
+
 /**
  * Checks if the Thread associated with this thread ID has been explored from
  * this Node already.
@@ -53,14 +77,11 @@ bool Node::backtrack_empty()
 }
 
 /**
- * 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());
 }
 
@@ -104,9 +125,25 @@ bool Node::is_enabled(Thread *t)
  * Add an action to the may_read_from set.
  * @param act is the action to add
  */
-void Node::add_read_from(ModelAction *act)
+void Node::add_read_from(const ModelAction *act)
 {
-	may_read_from.insert(act);
+	may_read_from.push_back(act);
+}
+
+/**
+ * Gets the next 'may_read_from' action from this Node. Only valid for a node
+ * where this->action is a 'read'.
+ * @todo Perform reads_from backtracking/replay properly, so that this function
+ * may remove elements from may_read_from
+ * @return The first element in may_read_from
+ */
+const ModelAction * Node::get_next_read_from() {
+	const ModelAction *act;
+	ASSERT(!may_read_from.empty());
+	act = may_read_from.front();
+	/* TODO: perform reads_from replay properly */
+	/* may_read_from.pop_front(); */
+	return act;
 }
 
 void Node::explore(thread_id_t tid)
@@ -173,7 +210,7 @@ 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;