2 * @brief Stack of operations for use in backtracking.
5 #ifndef __NODESTACK_H__
6 #define __NODESTACK_H__
14 #include "modeltypes.h"
21 * A flag used for the promise counting/combination problem within a node,
22 * denoting whether a particular Promise is
23 * <ol><li>@b applicable: can be satisfied by this Node's ModelAction and</li>
24 * <li>@b fulfilled: satisfied by this Node's ModelAction under the current
25 * configuration.</li></ol>
28 PROMISE_IGNORE = 0, /**< This promise is inapplicable; ignore it */
29 PROMISE_UNFULFILLED, /**< This promise is applicable but unfulfilled */
30 PROMISE_FULFILLED /**< This promise is applicable and fulfilled */
35 modelclock_t expiration;
38 struct fairness_info {
39 unsigned int enabled_count;
46 * @brief A single node in a NodeStack
48 * Represents a single node in the NodeStack. Each Node is associated with up
49 * to one action and up to one parent node. A node holds information
50 * regarding the last action performed (the "associated action"), the thread
51 * choices that have been explored (explored_children) and should be explored
52 * (backtrack), and the actions that the last action may read from.
56 Node(ModelAction *act = NULL, Node *par = NULL, int nthreads = 1, Node *prevfairness = NULL);
58 /* return true = thread choice has already been explored */
59 bool has_been_explored(thread_id_t tid);
60 /* return true = backtrack set is empty */
61 bool backtrack_empty();
63 void explore_child(ModelAction *act, enabled_type_t * is_enabled);
64 /* return false = thread was already in backtrack */
65 bool set_backtrack(thread_id_t id);
66 thread_id_t get_next_backtrack();
67 bool is_enabled(Thread *t);
68 bool is_enabled(thread_id_t tid);
69 ModelAction * get_action() { return action; }
70 bool has_priority(thread_id_t tid);
71 int get_num_threads() {return num_threads;}
72 /** @return the parent Node to this Node; that is, the action that
73 * occurred previously in the stack. */
74 Node * get_parent() const { return parent; }
76 bool add_future_value(uint64_t value, modelclock_t expiration);
77 uint64_t get_future_value();
78 modelclock_t get_future_value_expiration();
79 bool increment_future_value();
80 bool future_value_empty();
82 void add_read_from(const ModelAction *act);
83 const ModelAction * get_read_from();
84 bool increment_read_from();
85 bool read_from_empty();
86 int get_read_from_size();
87 const ModelAction * get_read_from_at(int i);
89 void set_promise(unsigned int i);
90 bool get_promise(unsigned int i);
91 bool increment_promise();
93 enabled_type_t *get_enabled_array() {return enabled_array;}
95 void add_relseq_break(const ModelAction *write);
96 const ModelAction * get_relseq_break();
97 bool increment_relseq_break();
98 bool relseq_break_empty();
101 void print_may_read_from();
105 void explore(thread_id_t tid);
110 std::vector< bool, ModelAlloc<bool> > explored_children;
111 std::vector< bool, ModelAlloc<bool> > backtrack;
112 std::vector< struct fairness_info, ModelAlloc< struct fairness_info> > fairness;
114 enabled_type_t *enabled_array;
116 /** The set of ModelActions that this the action at this Node may read
117 * from. Only meaningful if this Node represents a 'read' action. */
118 std::vector< const ModelAction *, ModelAlloc< const ModelAction * > > may_read_from;
120 unsigned int read_from_index;
122 std::vector< struct future_value, ModelAlloc<struct future_value> > future_values;
123 std::vector< promise_t, ModelAlloc<promise_t> > promises;
126 std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > relseq_break_writes;
127 int relseq_break_index;
130 typedef std::vector< Node *, ModelAlloc< Node * > > node_list_t;
133 * @brief A stack of nodes
135 * Holds a Node linked-list that can be used for holding backtracking,
136 * may-read-from, and replay information. It is used primarily as a
137 * stack-like structure, in that backtracking points and replay nodes are
138 * only removed from the top (most recent).
144 ModelAction * explore_action(ModelAction *act, enabled_type_t * is_enabled);
147 void reset_execution();
148 void pop_restofstack(int numAhead);
149 int get_total_nodes() { return total_nodes; }
155 node_list_t node_list;
161 #endif /* __NODESTACK_H__ */