X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=nodestack.cc;h=4ece1820ab86b35baad7c6ec1c7ee18b1a19c61b;hb=9c24e6ba4e89dfc1a6f0f23908510a3c1224b8d0;hp=d3b7c104316161d0268c8ae1b2db7a116fbbac74;hpb=f48c73aeda479368d4bfaf96fe9fe07f3d3d8bdb;p=model-checker.git

diff --git a/nodestack.cc b/nodestack.cc
index d3b7c10..4ece182 100644
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -24,7 +24,10 @@ Node::Node(ModelAction *act, Node *par, int nthreads)
 	explored_children(num_threads),
 	backtrack(num_threads),
 	numBacktracks(0),
-	may_read_from()
+	may_read_from(),
+	read_from_index(0),
+	future_values(),
+	future_index(-1)
 {
 	if (act)
 		act->set_node(this);
@@ -46,6 +49,70 @@ 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();
+}
+
+void Node::set_promise(uint32_t i) {
+	if (i>=promises.size())
+		promises.resize(i+1,0);
+	promises[i]=1;
+}
+
+bool Node::get_promise(uint32_t i) {
+	return (promises[i]==2);
+}
+
+bool Node::increment_promise() {
+	for (unsigned int i=0;i<promises.size();i++) {
+		if (promises[i]==1) {
+			promises[i]=2;
+			while (i>0) {
+				i--;
+				if (promises[i]==2)
+					promises[i]=1;
+			}
+			return true;
+		}
+	}
+	return false;
+}
+
+bool Node::promise_empty() {
+	for (unsigned int i=0;i<promises.size();i++)
+		if (promises[i]==1)
+			return false;
+	return true;
+}
+
+/**
+ * Adds a value from a weakly ordered future write to backtrack to.
+ * @param value is the value to backtrack to.
+ */
+
+bool Node::add_future_value(uint64_t value) {
+	for(unsigned int i=0;i<future_values.size();i++)
+		if (future_values[i]==value)
+			return false;
+
+	future_values.push_back(value);
+	return true;
+}
+
+/** 
+ * Checks whether the future_values set for this node is empty.
+ * @return true if the future_values set is empty.
+ */
+
+bool Node::future_value_empty() {
+	return ((future_index+1)>=future_values.size());
+}
+
+
 /**
  * Checks if the Thread associated with this thread ID has been explored from
  * this Node already.
@@ -65,11 +132,22 @@ bool Node::has_been_explored(thread_id_t tid)
  */
 bool Node::backtrack_empty()
 {
-	return numBacktracks == 0;
+	return (numBacktracks == 0);
 }
 
+
+/**
+ * Checks whether the readsfrom set for this node is empty.
+ * @return true if the readsfrom set is empty.
+ */
+bool Node::read_from_empty() {
+	return ((read_from_index+1)>=may_read_from.size());
+}
+
+
+
 /**
- * Mark the appropriate backtracking infromation for exploring a thread choice.
+ * Mark the appropriate backtracking information for exploring a thread choice.
  * @param act The ModelAction to explore
  */
 void Node::explore_child(ModelAction *act)
@@ -96,13 +174,14 @@ bool Node::set_backtrack(thread_id_t id)
 
 thread_id_t Node::get_next_backtrack()
 {
-	/* TODO: find next backtrack */
+	/** @todo Find next backtrack */
 	unsigned int i;
 	for (i = 0; i < backtrack.size(); i++)
 		if (backtrack[i] == true)
 			break;
-	if (i >= backtrack.size())
-		return THREAD_ID_T_NONE;
+	/* Backtrack set was empty? */
+	ASSERT(i != backtrack.size());
+
 	backtrack[i] = false;
 	numBacktracks--;
 	return int_to_id(i);
@@ -117,9 +196,53 @@ 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 'future_value' value from this Node. Only valid for a node
+ * where this->action is a 'read'.
+ * @return The first element in future_values
+ */
+
+uint64_t Node::get_future_value() {
+	ASSERT(future_index<future_values.size());
+	return future_values[future_index];
+}
+
+/**
+ * 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_read_from() {
+	if (read_from_index<may_read_from.size())
+		return may_read_from[read_from_index];
+	else
+		return NULL;
+}
+
+/**
+ * Increments the index into the readsfrom set to explore the next item.
+ * @return Returns false if we have explored all items.
+ */
+bool Node::increment_read_from() {
+	read_from_index++;
+	return (read_from_index<may_read_from.size());
+}
+
+/**
+ * Increments the index into the future_values set to explore the next item.
+ * @return Returns false if we have explored all values.
+ */
+
+bool Node::increment_future_value() {
+	future_index++;
+	return (future_index<future_values.size());
 }
 
 void Node::explore(thread_id_t tid)
@@ -173,17 +296,14 @@ ModelAction * NodeStack::explore_action(ModelAction *act)
 	DBG();
 
 	ASSERT(!node_list.empty());
+	node_list_t::iterator it=iter;
+	it++;
 
-	if (get_head()->has_been_explored(act->get_tid())) {
+	if (it != node_list.end()) {
 		iter++;
 		return (*iter)->get_action();
 	}
 
-	/* Diverging from previous execution; clear out remainder of list */
-	node_list_t::iterator it = iter;
-	it++;
-	clear_node_list(&node_list, it, node_list.end());
-
 	/* Record action */
 	get_head()->explore_child(act);
 	node_list.push_back(new Node(act, get_head(), model->get_num_threads()));
@@ -192,6 +312,23 @@ ModelAction * NodeStack::explore_action(ModelAction *act)
 	return NULL;
 }
 
+/**
+ * Empties the stack of all trailing nodes after a given position and calls the
+ * destructor for each. This function is provided an offset which determines
+ * how many nodes (relative to the current replay state) to save before popping
+ * the stack.
+ * @param numAhead gives the number of Nodes (including this Node) to skip over
+ * before removing nodes.
+ */
+void NodeStack::pop_restofstack(int numAhead)
+{
+	/* Diverging from previous execution; clear out remainder of list */
+	node_list_t::iterator it = iter;
+	while (numAhead--)
+		it++;
+	clear_node_list(&node_list, it, node_list.end());
+}
+
 Node * NodeStack::get_head()
 {
 	if (node_list.empty())