2 * @brief Stack of operations for use in backtracking.
5 #ifndef __NODESTACK_H__
6 #define __NODESTACK_H__
19 struct fairness_info {
20 unsigned int enabled_count;
33 * @brief A single node in a NodeStack
35 * Represents a single node in the NodeStack. Each Node is associated with up
36 * to one action and up to one parent node. A node holds information
37 * regarding the last action performed (the "associated action"), the thread
38 * choices that have been explored (explored_children) and should be explored
39 * (backtrack), and the actions that the last action may read from.
43 Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness);
45 /* return true = thread choice has already been explored */
46 bool has_been_explored(thread_id_t tid) const;
47 /* return true = backtrack set is empty */
48 bool backtrack_empty() const;
50 void clear_backtracking();
51 void explore_child(ModelAction *act, enabled_type_t *is_enabled);
52 /* return false = thread was already in backtrack */
53 bool set_backtrack(thread_id_t id);
54 thread_id_t get_next_backtrack();
55 bool is_enabled(Thread *t) const;
56 bool is_enabled(thread_id_t tid) const;
57 enabled_type_t enabled_status(thread_id_t tid) const;
59 ModelAction * get_action() const { return action; }
60 bool has_priority(thread_id_t tid) const;
61 int get_num_threads() const { return num_threads; }
62 /** @return the parent Node to this Node; that is, the action that
63 * occurred previously in the stack. */
64 Node * get_parent() const { return parent; }
66 read_from_type_t get_read_from_status();
67 bool increment_read_from();
68 bool read_from_empty() const;
69 unsigned int read_from_size() const;
71 void print_read_from_past();
72 void add_read_from_past(const ModelAction *act);
73 const ModelAction * get_read_from_past() const;
74 const ModelAction * get_read_from_past(int i) const;
75 int get_read_from_past_size() const;
77 void add_read_from_promise(const ModelAction *reader);
78 Promise * get_read_from_promise() const;
79 Promise * get_read_from_promise(int i) const;
80 int get_read_from_promise_size() const;
82 bool add_future_value(struct future_value fv);
83 struct future_value get_future_value() const;
85 void set_promise(unsigned int i);
86 bool get_promise(unsigned int i) const;
87 bool increment_promise();
88 bool promise_empty() const;
89 void clear_promise_resolutions();
91 enabled_type_t *get_enabled_array() {return enabled_array;}
93 void set_misc_max(int i);
95 bool increment_misc();
96 bool misc_empty() const;
98 void add_relseq_break(const ModelAction *write);
99 const ModelAction * get_relseq_break() const;
100 bool increment_relseq_break();
101 bool relseq_break_empty() const;
107 void explore(thread_id_t tid);
109 bool read_from_past_empty() const;
110 bool increment_read_from_past();
111 bool read_from_promise_empty() const;
112 bool increment_read_from_promise();
113 bool future_value_empty() const;
114 bool increment_future_value();
115 read_from_type_t read_from_status;
117 ModelAction * const action;
119 const int num_threads;
120 std::vector< bool, ModelAlloc<bool> > explored_children;
121 std::vector< bool, ModelAlloc<bool> > backtrack;
122 std::vector< struct fairness_info, ModelAlloc< struct fairness_info> > fairness;
124 enabled_type_t *enabled_array;
127 * The set of past ModelActions that this the action at this Node may
128 * read from. Only meaningful if this Node represents a 'read' action.
130 std::vector< const ModelAction *, ModelAlloc< const ModelAction * > > read_from_past;
131 unsigned int read_from_past_idx;
133 std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > read_from_promises;
134 int read_from_promise_idx;
136 std::vector< struct future_value, ModelAlloc<struct future_value> > future_values;
139 std::vector< bool, ModelAlloc<bool> > resolve_promise;
140 int resolve_promise_idx;
142 std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > relseq_break_writes;
143 int relseq_break_index;
149 typedef std::vector< Node *, ModelAlloc< Node * > > node_list_t;
152 * @brief A stack of nodes
154 * Holds a Node linked-list that can be used for holding backtracking,
155 * may-read-from, and replay information. It is used primarily as a
156 * stack-like structure, in that backtracking points and replay nodes are
157 * only removed from the top (most recent).
163 ModelAction * explore_action(ModelAction *act, enabled_type_t * is_enabled);
164 Node * get_head() const;
165 Node * get_next() const;
166 void reset_execution();
167 void pop_restofstack(int numAhead);
168 int get_total_nodes() { return total_nodes; }
174 node_list_t node_list;
177 * @brief the index position of the current head Node
179 * This index is relative to node_list. The index should point to the
180 * current head Node. It is negative when the list is empty.
187 #endif /* __NODESTACK_H__ */