X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=nodestack.cc;h=431baafbdce9809a2cb49ebcea30837182c852cf;hb=cdf3ae3d7205018a412f75addf4113587a1a0586;hp=1de51693eea6ecd606fe3fd616536fa152cfdc4f;hpb=47129ff6e38cd62e7a14193810a22c5fc2c70124;p=model-checker.git

diff --git a/nodestack.cc b/nodestack.cc
index 1de5169..431baaf 100644
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -25,7 +25,9 @@ Node::Node(ModelAction *act, Node *par, int nthreads)
 	backtrack(num_threads),
 	numBacktracks(0),
 	may_read_from(),
-	read_from_index(0)
+	read_from_index(0),
+	future_values(),
+	future_index(-1)
 {
 	if (act)
 		act->set_node(this);
@@ -50,9 +52,91 @@ void Node::print()
 /** @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();
+	for (unsigned int i = 0; i < may_read_from.size(); i++)
+		may_read_from[i]->print();
+}
+
+/**
+ * Sets a promise to explore meeting with the given node.
+ * @param i is the promise index.
+ */
+void Node::set_promise(unsigned int i) {
+	if (i >= promises.size())
+		promises.resize(i + 1, PROMISE_IGNORE);
+	if (promises[i] == PROMISE_IGNORE)
+		promises[i] = PROMISE_UNFULFILLED;
+}
+
+/**
+ * Looks up whether a given promise should be satisfied by this node.
+ * @param i The promise index.
+ * @return true if the promise should be satisfied by the given model action.
+ */
+bool Node::get_promise(unsigned int i) {
+	return (i < promises.size()) && (promises[i] == PROMISE_FULFILLED);
+}
+
+/**
+ * Increments to the next combination of promises.
+ * @return true if we have a valid combination.
+ */
+bool Node::increment_promise() {
+	for (unsigned int i = 0; i < promises.size(); i++) {
+		if (promises[i] == PROMISE_UNFULFILLED) {
+			promises[i] = PROMISE_FULFILLED;
+			while (i > 0) {
+				i--;
+				if (promises[i] == PROMISE_FULFILLED)
+					promises[i] = PROMISE_UNFULFILLED;
+			}
+			return true;
+		}
+	}
+	return false;
+}
+
+/**
+ * Returns whether the promise set is empty.
+ * @return true if we have explored all promise combinations.
+ */
+bool Node::promise_empty() {
+	for (unsigned int i = 0; i < promises.size();i++)
+		if (promises[i] == PROMISE_UNFULFILLED)
+			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, modelclock_t expiration) {
+	int suitableindex=-1;
+	for (unsigned int i = 0; i < future_values.size(); i++) {
+		if (future_values[i].value == value) {
+			if (future_values[i].expiration>=expiration)
+				return false;
+			if (future_index < i) {
+				suitableindex=i;
+			}
+		}
+	}
+
+	if (suitableindex!=-1) {
+		future_values[suitableindex].expiration=expiration;
+		return true;
+	}
+	struct future_value newfv={value, expiration};
+	future_values.push_back(newfv);
+	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());
 }
 
 /**
@@ -77,12 +161,16 @@ bool Node::backtrack_empty()
 	return (numBacktracks == 0);
 }
 
-bool Node::readsfrom_empty() {
-	return ((read_from_index+1)>=may_read_from.size());
+/**
+ * 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)
@@ -109,7 +197,7 @@ 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)
@@ -136,21 +224,58 @@ void Node::add_read_from(const ModelAction *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].value;
+}
+
+modelclock_t Node::get_future_value_expiration() {
+	ASSERT(future_index<future_values.size());
+	return future_values[future_index].expiration;
+}
+
+
+int Node::get_read_from_size() {
+	return may_read_from.size();
+}
+
+const ModelAction * Node::get_read_from_at(int i) {
+	return may_read_from[i];
+}
+
 /**
  * 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() {
-	ASSERT(read_from_index<may_read_from.size());
-	return may_read_from[read_from_index];
+	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());
+	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)
@@ -164,7 +289,7 @@ void Node::explore(thread_id_t tid)
 }
 
 static void clear_node_list(node_list_t *list, node_list_t::iterator start,
-					       node_list_t::iterator end)
+                                               node_list_t::iterator end)
 {
 	node_list_t::iterator it;
 
@@ -225,7 +350,8 @@ ModelAction * NodeStack::explore_action(ModelAction *act)
  * 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 The number of nodes to skip forward 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)
 {