2 * @brief Stack of operations for use in backtracking.
5 #ifndef __NODESTACK_H__
6 #define __NODESTACK_H__
20 * A flag used for the promise counting/combination problem within a node,
21 * denoting whether a particular Promise is
22 * <ol><li>@b applicable: can be satisfied by this Node's ModelAction and</li>
23 * <li>@b fulfilled: satisfied by this Node's ModelAction under the current
24 * configuration.</li></ol>
27 #define PROMISE_IGNORE 0 /**< This promise is inapplicable; ignore it */
28 #define PROMISE_UNFULFILLED 1 /**< This promise is applicable but unfulfilled */
29 #define PROMISE_FULFILLED 2 /**< This promise is applicable and fulfilled */
30 #define PROMISE_MASK 0xf
31 #define PROMISE_RMW 0x10
33 typedef int promise_t;
35 struct fairness_info {
36 unsigned int enabled_count;
42 * @brief A single node in a NodeStack
44 * Represents a single node in the NodeStack. Each Node is associated with up
45 * to one action and up to one parent node. A node holds information
46 * regarding the last action performed (the "associated action"), the thread
47 * choices that have been explored (explored_children) and should be explored
48 * (backtrack), and the actions that the last action may read from.
52 Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness);
54 /* return true = thread choice has already been explored */
55 bool has_been_explored(thread_id_t tid) const;
56 /* return true = backtrack set is empty */
57 bool backtrack_empty() const;
59 void clear_backtracking();
60 void explore_child(ModelAction *act, enabled_type_t *is_enabled);
61 /* return false = thread was already in backtrack */
62 bool set_backtrack(thread_id_t id);
63 thread_id_t get_next_backtrack();
64 bool is_enabled(Thread *t) const;
65 bool is_enabled(thread_id_t tid) const;
66 enabled_type_t enabled_status(thread_id_t tid) const;
68 ModelAction * get_action() const { return action; }
69 bool has_priority(thread_id_t tid) const;
70 int get_num_threads() const { return num_threads; }
71 /** @return the parent Node to this Node; that is, the action that
72 * occurred previously in the stack. */
73 Node * get_parent() const { return parent; }
75 bool add_future_value(struct future_value fv);
76 struct future_value get_future_value() const;
77 bool increment_future_value();
78 bool future_value_empty() const;
80 void add_read_from_past(const ModelAction *act);
81 const ModelAction * get_read_from_past() const;
82 bool increment_read_from_past();
83 bool read_from_past_empty() const;
84 int get_read_from_past_size() const;
85 const ModelAction * get_read_from_past(int i) const;
87 void set_promise(unsigned int i, bool is_rmw);
88 bool get_promise(unsigned int i) const;
89 bool increment_promise();
90 bool promise_empty() const;
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;
104 void print_read_from_past();
108 void explore(thread_id_t tid);
110 ModelAction * const action;
112 const int num_threads;
113 std::vector< bool, ModelAlloc<bool> > explored_children;
114 std::vector< bool, ModelAlloc<bool> > backtrack;
115 std::vector< struct fairness_info, ModelAlloc< struct fairness_info> > fairness;
117 enabled_type_t *enabled_array;
120 * The set of past ModelActions that this the action at this Node may
121 * read from. Only meaningful if this Node represents a 'read' action.
123 std::vector< const ModelAction *, ModelAlloc< const ModelAction * > > read_from_past;
124 unsigned int read_from_past_idx;
126 std::vector< struct future_value, ModelAlloc<struct future_value> > future_values;
127 std::vector< promise_t, ModelAlloc<promise_t> > promises;
130 std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > relseq_break_writes;
131 int relseq_break_index;
137 typedef std::vector< Node *, ModelAlloc< Node * > > node_list_t;
140 * @brief A stack of nodes
142 * Holds a Node linked-list that can be used for holding backtracking,
143 * may-read-from, and replay information. It is used primarily as a
144 * stack-like structure, in that backtracking points and replay nodes are
145 * only removed from the top (most recent).
151 ModelAction * explore_action(ModelAction *act, enabled_type_t * is_enabled);
152 Node * get_head() const;
153 Node * get_next() const;
154 void reset_execution();
155 void pop_restofstack(int numAhead);
156 int get_total_nodes() { return total_nodes; }
162 node_list_t node_list;
165 * @brief the index position of the current head Node
167 * This index is relative to node_list. The index should point to the
168 * current head Node. It is negative when the list is empty.
175 #endif /* __NODESTACK_H__ */