2 * @brief Core model checker.
15 #include "hashtable.h"
16 #include "workqueue.h"
18 #include "modeltypes.h"
20 /* Forward declaration */
26 struct model_snapshot_members;
28 /** @brief Shorthand for a list of release sequence heads */
29 typedef std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > rel_heads_list_t;
32 * Model checker parameter structure. Holds run-time configuration options for
38 unsigned int fairwindow;
39 unsigned int enabledcount;
42 /** @brief Maximum number of future values that can be sent to the same
46 /** @brief Only generate a new future value/expiration pair if the
47 * expiration time exceeds the existing one by more than the slop
49 unsigned int expireslop;
51 /** @brief Verbosity (0 = quiet; 1 = noisy) */
54 /** @brief Command-line argument count to pass to user program */
57 /** @brief Command-line arguments to pass to user program */
61 /** @brief Model checker execution stats */
62 struct execution_stats {
63 int num_total; /**< @brief Total number of executions */
64 int num_infeasible; /**< @brief Number of infeasible executions */
65 int num_buggy_executions; /** @brief Number of buggy executions */
66 int num_complete; /**< @brief Number of feasible, non-buggy, complete executions */
67 int num_redundant; /**< @brief Number of redundant, aborted executions */
70 struct PendingFutureValue {
75 /** @brief Records information regarding a single pending release sequence */
77 /** @brief The acquire operation */
79 /** @brief The head of the RMW chain from which 'acquire' reads; may be
80 * equal to 'release' */
81 const ModelAction *rf;
82 /** @brief The head of the potential longest release sequence chain */
83 const ModelAction *release;
84 /** @brief The write(s) that may break the release sequence */
85 std::vector<const ModelAction *> writes;
88 /** @brief The central structure for model-checking */
91 ModelChecker(struct model_params params);
94 /** @returns the context for the main model-checking system thread */
95 ucontext_t * get_system_context() { return &system_context; }
97 void print_summary() const;
98 #if SUPPORT_MOD_ORDER_DUMP
99 void dumpGraph(char *filename);
102 void add_thread(Thread *t);
103 void remove_thread(Thread *t);
104 Thread * get_thread(thread_id_t tid) const;
105 Thread * get_thread(ModelAction *act) const;
107 bool is_enabled(Thread *t) const;
108 bool is_enabled(thread_id_t tid) const;
110 thread_id_t get_next_id();
111 unsigned int get_num_threads() const;
112 Thread * get_current_thread();
114 int switch_to_master(ModelAction *act);
115 ClockVector * get_cv(thread_id_t tid);
116 ModelAction * get_parent_action(thread_id_t tid);
117 bool next_execution();
118 bool isfeasible() const;
119 bool isfeasibleotherthanRMW() const;
120 bool isfinalfeasible() const;
121 void check_promises_thread_disabled();
122 void mo_check_promises(thread_id_t tid, const ModelAction *write);
123 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
124 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
125 void finish_execution();
126 bool isfeasibleprefix() const;
128 bool assert_bug(const char *msg);
129 void assert_user_bug(const char *msg);
131 bool is_deadlocked() const;
132 bool is_complete_execution() const;
133 void print_stats() const;
135 void set_bad_synchronization();
137 const model_params params;
138 Node * get_curr_node();
142 /** The scheduler to use: tracks the running/ready Threads */
143 Scheduler *scheduler;
145 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
146 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
147 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
148 bool has_asserted() const;
150 bool promises_expired() const;
151 void execute_sleep_set();
152 void wake_up_sleeping_actions(ModelAction * curr);
153 modelclock_t get_next_seq_num();
155 void set_current_action(ModelAction *act);
156 Thread * check_current_action(ModelAction *curr);
157 bool initialize_curr_action(ModelAction **curr);
158 bool process_read(ModelAction *curr, bool second_part_of_rmw);
159 bool process_write(ModelAction *curr);
160 bool process_mutex(ModelAction *curr);
161 bool process_thread_action(ModelAction *curr);
162 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
163 bool check_action_enabled(ModelAction *curr);
167 void check_recency(ModelAction *curr, const ModelAction *rf);
168 ModelAction * get_last_conflict(ModelAction *act);
169 void set_backtracking(ModelAction *act);
170 Thread * get_next_thread(ModelAction *curr);
171 ModelAction * get_next_backtrack();
172 void reset_to_initial_state();
173 bool resolve_promises(ModelAction *curr);
174 void compute_promises(ModelAction *curr);
175 void compute_relseq_breakwrites(ModelAction *curr);
177 void check_curr_backtracking(ModelAction * curr);
178 void add_action_to_lists(ModelAction *act);
179 ModelAction * get_last_action(thread_id_t tid) const;
180 ModelAction * get_last_seq_cst(ModelAction *curr) const;
181 ModelAction * get_last_unlock(ModelAction *curr) const;
182 void build_reads_from_past(ModelAction *curr);
183 ModelAction * process_rmw(ModelAction *curr);
184 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
185 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
186 bool w_modification_order(ModelAction *curr);
187 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
188 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
190 ModelAction *diverge;
191 ModelAction *earliest_diverge;
193 ucontext_t system_context;
194 action_list_t *action_trace;
195 HashTable<int, Thread *, int> *thread_map;
197 /** Per-object list of actions. Maps an object (i.e., memory location)
198 * to a trace of all actions performed on the object. */
199 HashTable<const void *, action_list_t *, uintptr_t, 4> *obj_map;
201 /** Per-object list of actions. Maps an object (i.e., memory location)
202 * to a trace of all actions performed on the object. */
203 HashTable<const void *, action_list_t *, uintptr_t, 4> *lock_waiters_map;
205 /** Per-object list of actions. Maps an object (i.e., memory location)
206 * to a trace of all actions performed on the object. */
207 HashTable<const void *, action_list_t *, uintptr_t, 4> *condvar_waiters_map;
209 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > *obj_thrd_map;
210 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
211 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
214 * List of pending release sequences. Release sequences might be
215 * determined lazily as promises are fulfilled and modification orders
216 * are established. Each entry in the list may only be partially
217 * filled, depending on its pending status.
219 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
221 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
222 NodeStack *node_stack;
224 /** Private data members that should be snapshotted. They are grouped
225 * together for efficiency and maintainability. */
226 struct model_snapshot_members *priv;
228 /** A special model-checker Thread; used for associating with
229 * model-checker-related ModelAcitons */
230 Thread *model_thread;
233 * @brief The modification order graph
235 * A directed acyclic graph recording observations of the modification
236 * order on all the atomic objects in the system. This graph should
237 * never contain any cycles, as that represents a violation of the
238 * memory model (total ordering). This graph really consists of many
239 * disjoint (unconnected) subgraphs, each graph corresponding to a
240 * separate ordering on a distinct object.
242 * The edges in this graph represent the "ordered before" relation,
243 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
246 CycleGraph *mo_graph;
248 /** @brief The cumulative execution stats */
249 struct execution_stats stats;
252 bool have_bug_reports() const;
253 void print_bugs() const;
254 void print_execution(bool printbugs) const;
257 extern ModelChecker *model;
259 #endif /* __MODEL_H__ */