X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=nodestack.h;h=16264a2bbf800c6832e312cab644e85febb4f566;hb=bdef0741b8a01e16946d261bc2a657af5a683b3e;hp=af7808227b420ff431a3549490dc37e55a36fd08;hpb=e725e347266a91be41447dba497f57f3b6d5413c;p=model-checker.git

diff --git a/nodestack.h b/nodestack.h
index af78082..16264a2 100644
--- a/nodestack.h
+++ b/nodestack.h
@@ -1,3 +1,7 @@
+/** @file nodestack.h
+ *  @brief Stack of operations for use in backtracking.
+*/
+
 #ifndef __NODESTACK_H__
 #define __NODESTACK_H__
 
@@ -9,14 +13,28 @@
 
 class ModelAction;
 
+typedef std::vector< const ModelAction *, MyAlloc< const ModelAction * > > readfrom_set_t;
+typedef std::vector< uint64_t, MyAlloc< uint64_t > > futurevalues_t;
+
+/**
+ * @brief A single node in a NodeStack
+ *
+ * Represents a single node in the NodeStack. Each Node is associated with up
+ * to one action and up to one parent node. A node holds information
+ * regarding the last action performed (the "associated action"), the thread
+ * choices that have been explored (explored_children) and should be explored
+ * (backtrack), and the actions that the last action may read from.
+ */
 class Node {
 public:
-	Node(ModelAction *act = NULL, int nthreads = 1);
+	Node(ModelAction *act = NULL, Node *par = NULL, int nthreads = 1);
 	~Node();
 	/* return true = thread choice has already been explored */
 	bool has_been_explored(thread_id_t tid);
 	/* return true = backtrack set is empty */
 	bool backtrack_empty();
+	bool readsfrom_empty();
+	bool futurevalues_empty();
 	void explore_child(ModelAction *act);
 	/* return false = thread was already in backtrack */
 	bool set_backtrack(thread_id_t id);
@@ -24,31 +42,60 @@ public:
 	bool is_enabled(Thread *t);
 	ModelAction * get_action() { return action; }
 
-	void print();
+	/** @return the parent Node to this Node; that is, the action that
+	 * occurred previously in the stack. */
+	Node * get_parent() const { return parent; }
+
+	void add_future_value(uint64_t value);
+	void add_read_from(const ModelAction *act);
+	const ModelAction * get_read_from();
+	uint64_t get_future_value();
+	bool increment_read_from();
+	bool increment_future_values();
 
-	static int get_total_nodes() { return total_nodes; }
+	void print();
+	void print_may_read_from();
 
 	MEMALLOC
 private:
 	void explore(thread_id_t tid);
 
-	static int total_nodes;
 	ModelAction *action;
+	Node *parent;
 	int num_threads;
 	std::vector< bool, MyAlloc<bool> > explored_children;
 	std::vector< bool, MyAlloc<bool> > backtrack;
+	int numBacktracks;
+
+	/** The set of ModelActions that this the action at this Node may read
+	 *  from. Only meaningful if this Node represents a 'read' action. */
+	readfrom_set_t may_read_from;
+	unsigned int read_from_index;
+
+	futurevalues_t future_values;
+	unsigned int future_index;
 };
 
-typedef std::list<class Node *, MyAlloc< class Node * > > node_list_t;
+typedef std::list< Node *, MyAlloc< Node * > > node_list_t;
 
+/**
+ * @brief A stack of nodes
+ *
+ * Holds a Node linked-list that can be used for holding backtracking,
+ * may-read-from, and replay information. It is used primarily as a
+ * stack-like structure, in that backtracking points and replay nodes are
+ * only removed from the top (most recent).
+ */
 class NodeStack {
 public:
 	NodeStack();
 	~NodeStack();
-	ModelAction * explore_action(ModelAction *act, ModelAction *parent);
+	ModelAction * explore_action(ModelAction *act);
 	Node * get_head();
 	Node * get_next();
 	void reset_execution();
+	void pop_restofstack(int numAhead);
+	int get_total_nodes() { return total_nodes; }
 
 	void print();
 
@@ -56,6 +103,8 @@ public:
 private:
 	node_list_t node_list;
 	node_list_t::iterator iter;
+
+	int total_nodes;
 };
 
 #endif /* __NODESTACK_H__ */