some changes towards reading from future writes

[model-checker.git] / nodestack.h

diff --git a/nodestack.h b/nodestack.h
index 2fd84ddeb11e98171ffacefa2fadad1e704079c4..16264a2bbf800c6832e312cab644e85febb4f566 100644 (file)
--- 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__
 
@@ -5,17 +9,32 @@
 #include <vector>
 #include <cstddef>
 #include "threads.h"
+#include "mymemory.h"
 
 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, Node *parent = NULL);
+       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);
@@ -23,21 +42,50 @@ public:
        bool is_enabled(Thread *t);
        ModelAction * get_action() { return action; }
 
+       /** @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();
+
        void print();
+       void print_may_read_from();
 
-       static int get_total_nodes() { return total_nodes; }
+       MEMALLOC
 private:
        void explore(thread_id_t tid);
 
-       static int total_nodes;
        ModelAction *action;
+       Node *parent;
        int num_threads;
-       std::vector<bool> explored_children;
-       std::vector<bool> backtrack;
+       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 *> 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();
@@ -46,11 +94,17 @@ public:
        Node * get_head();
        Node * get_next();
        void reset_execution();
+       void pop_restofstack(int numAhead);
+       int get_total_nodes() { return total_nodes; }
 
        void print();
+
+       MEMALLOC
 private:
        node_list_t node_list;
        node_list_t::iterator iter;
+
+       int total_nodes;
 };
 
 #endif /* __NODESTACK_H__ */