2 * @brief Core model checker.
15 #include "libthreads.h"
18 #include "clockvector.h"
19 #include "hashtable.h"
21 /* Forward declaration */
27 * Model checker parameter structure. Holds run-time configuration options for
35 * Structure for holding small ModelChecker members that should be snapshotted
37 struct model_snapshot_members {
38 ModelAction *current_action;
40 modelclock_t used_sequence_numbers;
42 ModelAction *next_backtrack;
44 /** @see ModelChecker::lazy_sync_size */
45 unsigned int lazy_sync_size;
48 /** @brief The central structure for model-checking */
51 ModelChecker(struct model_params params);
54 /** @returns the context for the main model-checking system thread */
55 ucontext_t * get_system_context() { return &system_context; }
57 /** Prints an execution summary with trace information. */
60 void add_thread(Thread *t);
61 void remove_thread(Thread *t);
62 Thread * get_thread(thread_id_t tid) { return thread_map->get(id_to_int(tid)); }
63 Thread * get_thread(ModelAction *act) { return get_thread(act->get_tid()); }
65 thread_id_t get_next_id();
66 int get_num_threads();
67 modelclock_t get_next_seq_num();
69 /** @return The currently executing Thread. */
70 Thread * get_current_thread() { return scheduler->get_current_thread(); }
72 int switch_to_master(ModelAction *act);
73 ClockVector * get_cv(thread_id_t tid);
74 ModelAction * get_parent_action(thread_id_t tid);
75 bool next_execution();
77 bool isfinalfeasible();
78 void check_promises(ClockVector *old_cv, ClockVector * merge_cv);
79 void get_release_seq_heads(ModelAction *act,
80 std::vector<const ModelAction *> *release_heads);
82 void finish_execution();
83 bool isfeasibleprefix();
84 void set_assert() {asserted=true;}
88 /** The scheduler to use: tracks the running/ready Threads */
91 bool has_asserted() {return asserted;}
92 void reset_asserted() {asserted=false;}
95 const model_params params;
98 * Stores the ModelAction for the current thread action. Call this
99 * immediately before switching from user- to system-context to pass
101 * @param act The ModelAction created by the user-thread action
103 void set_current_action(ModelAction *act) { priv->current_action = act; }
104 Thread * check_current_action(ModelAction *curr);
105 bool process_read(ModelAction *curr, Thread * th, bool second_part_of_rmw);
109 void check_recency(ModelAction *curr, bool already_added);
110 ModelAction * get_last_conflict(ModelAction *act);
111 void set_backtracking(ModelAction *act);
112 Thread * get_next_thread(ModelAction *curr);
113 ModelAction * get_next_backtrack();
114 void reset_to_initial_state();
115 bool resolve_promises(ModelAction *curr);
116 void compute_promises(ModelAction *curr);
118 void add_action_to_lists(ModelAction *act);
119 ModelAction * get_last_action(thread_id_t tid);
120 ModelAction * get_last_seq_cst(const void *location);
121 void build_reads_from_past(ModelAction *curr);
122 ModelAction * process_rmw(ModelAction *curr);
123 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
124 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
125 bool w_modification_order(ModelAction *curr);
126 bool release_seq_head(const ModelAction *rf,
127 std::vector<const ModelAction *> *release_heads) const;
128 bool resolve_release_sequences(void *location);
130 ModelAction *diverge;
132 ucontext_t system_context;
133 action_list_t *action_trace;
134 HashTable<int, Thread *, int> *thread_map;
136 /** Per-object list of actions. Maps an object (i.e., memory location)
137 * to a trace of all actions performed on the object. */
138 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
140 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
141 std::vector<Promise *> *promises;
144 * Collection of lists of objects that might synchronize with one or
145 * more release sequence. Release sequences might be determined lazily
146 * as promises are fulfilled and modification orders are established.
147 * This structure maps its lists by object location. Each ModelAction
148 * in the lists should be an acquire operation.
150 HashTable<void *, std::list<ModelAction *>, uintptr_t, 4> *lazy_sync_with_release;
153 * Represents the total size of the
154 * ModelChecker::lazy_sync_with_release lists. This count should be
155 * snapshotted, so it is actually a pointer to a location within
158 unsigned int *lazy_sync_size;
160 std::vector<ModelAction *> *thrd_last_action;
161 NodeStack *node_stack;
163 /** Private data members that should be snapshotted. They are grouped
164 * together for efficiency and maintainability. */
165 struct model_snapshot_members *priv;
168 * @brief The modification order graph
170 * A directed acyclic graph recording observations of the modification
171 * order on all the atomic objects in the system. This graph should
172 * never contain any cycles, as that represents a violation of the
173 * memory model (total ordering). This graph really consists of many
174 * disjoint (unconnected) subgraphs, each graph corresponding to a
175 * separate ordering on a distinct object.
177 * The edges in this graph represent the "ordered before" relation,
178 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
181 CycleGraph *mo_graph;
187 extern ModelChecker *model;
189 #endif /* __MODEL_H__ */