2 * @brief Core model checker.
14 #include "hashtable.h"
15 #include "workqueue.h"
17 #include "modeltypes.h"
19 /* Forward declaration */
25 struct model_snapshot_members;
27 /** @brief Shorthand for a list of release sequence heads */
28 typedef std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > rel_heads_list_t;
30 typedef std::list< ModelAction *, SnapshotAlloc<ModelAction *> > action_list_t;
33 * Model checker parameter structure. Holds run-time configuration options for
39 unsigned int fairwindow;
40 unsigned int enabledcount;
43 /** @brief Maximum number of future values that can be sent to the same
47 /** @brief Only generate a new future value/expiration pair if the
48 * expiration time exceeds the existing one by more than the slop
50 unsigned int expireslop;
52 /** @brief Verbosity (0 = quiet; 1 = noisy) */
55 /** @brief Command-line argument count to pass to user program */
58 /** @brief Command-line arguments to pass to user program */
62 /** @brief Model checker execution stats */
63 struct execution_stats {
64 int num_total; /**< @brief Total number of executions */
65 int num_infeasible; /**< @brief Number of infeasible executions */
66 int num_buggy_executions; /** @brief Number of buggy executions */
67 int num_complete; /**< @brief Number of feasible, non-buggy, complete executions */
68 int num_redundant; /**< @brief Number of redundant, aborted executions */
71 struct PendingFutureValue {
72 PendingFutureValue(ModelAction *writer, ModelAction *act) : writer(writer), act(act) { }
73 const ModelAction *writer;
77 /** @brief Records information regarding a single pending release sequence */
79 /** @brief The acquire operation */
81 /** @brief The read operation that may read from a release sequence;
82 * may be the same as acquire, or else an earlier action in the same
83 * thread (i.e., when 'acquire' is a fence-acquire) */
84 const ModelAction *read;
85 /** @brief The head of the RMW chain from which 'read' reads; may be
86 * equal to 'release' */
87 const ModelAction *rf;
88 /** @brief The head of the potential longest release sequence chain */
89 const ModelAction *release;
90 /** @brief The write(s) that may break the release sequence */
91 std::vector<const ModelAction *> writes;
94 /** @brief The central structure for model-checking */
97 ModelChecker(struct model_params params);
102 /** @returns the context for the main model-checking system thread */
103 ucontext_t * get_system_context() { return &system_context; }
105 void print_summary() const;
106 #if SUPPORT_MOD_ORDER_DUMP
107 void dumpGraph(char *filename) const;
110 void add_thread(Thread *t);
111 void remove_thread(Thread *t);
112 Thread * get_thread(thread_id_t tid) const;
113 Thread * get_thread(const ModelAction *act) const;
115 bool is_enabled(Thread *t) const;
116 bool is_enabled(thread_id_t tid) const;
118 thread_id_t get_next_id();
119 unsigned int get_num_threads() const;
120 Thread * get_current_thread() const;
122 void switch_from_master(Thread *thread);
123 uint64_t switch_to_master(ModelAction *act);
124 ClockVector * get_cv(thread_id_t tid) const;
125 ModelAction * get_parent_action(thread_id_t tid) const;
126 void check_promises_thread_disabled();
127 void mo_check_promises(const ModelAction *act, bool is_read_check);
128 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector *merge_cv);
129 bool isfeasibleprefix() const;
131 bool assert_bug(const char *msg);
132 void assert_user_bug(const char *msg);
134 const model_params params;
135 Node * get_curr_node() const;
139 /** The scheduler to use: tracks the running/ready Threads */
140 Scheduler *scheduler;
142 bool sleep_can_read_from(ModelAction *curr, const ModelAction *write);
143 bool thin_air_constraint_may_allow(const ModelAction *writer, const ModelAction *reader);
144 bool mo_may_allow(const ModelAction *writer, const ModelAction *reader);
145 bool has_asserted() const;
147 void set_bad_synchronization();
148 bool promises_expired() const;
149 void execute_sleep_set();
150 void wake_up_sleeping_actions(ModelAction *curr);
151 modelclock_t get_next_seq_num();
153 bool next_execution();
154 ModelAction * check_current_action(ModelAction *curr);
155 bool initialize_curr_action(ModelAction **curr);
156 bool process_read(ModelAction *curr, bool second_part_of_rmw);
157 bool process_write(ModelAction *curr);
158 bool process_fence(ModelAction *curr);
159 bool process_mutex(ModelAction *curr);
160 bool process_thread_action(ModelAction *curr);
161 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
162 bool read_from(ModelAction *act, const ModelAction *rf);
163 bool check_action_enabled(ModelAction *curr);
165 Thread * take_step(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 bool set_latest_backtrack(ModelAction *act);
172 ModelAction * get_next_backtrack();
173 void reset_to_initial_state();
174 bool resolve_promises(ModelAction *curr);
175 void compute_promises(ModelAction *curr);
176 void compute_relseq_breakwrites(ModelAction *curr);
178 void check_curr_backtracking(ModelAction *curr);
179 void add_action_to_lists(ModelAction *act);
180 ModelAction * get_last_action(thread_id_t tid) const;
181 ModelAction * get_last_fence_release(thread_id_t tid) const;
182 ModelAction * get_last_seq_cst_write(ModelAction *curr) const;
183 ModelAction * get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) const;
184 ModelAction * get_last_unlock(ModelAction *curr) const;
185 void build_reads_from_past(ModelAction *curr);
186 ModelAction * process_rmw(ModelAction *curr);
188 template <typename rf_type>
189 bool r_modification_order(ModelAction *curr, const rf_type *rf);
191 bool w_modification_order(ModelAction *curr);
192 void get_release_seq_heads(ModelAction *acquire, ModelAction *read, rel_heads_list_t *release_heads);
193 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
194 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
195 void add_future_value(const ModelAction *writer, ModelAction *reader);
197 ModelAction * new_uninitialized_action(void *location) const;
199 ModelAction *diverge;
200 ModelAction *earliest_diverge;
202 ucontext_t system_context;
203 action_list_t *action_trace;
204 HashTable<int, Thread *, int> *thread_map;
206 /** Per-object list of actions. Maps an object (i.e., memory location)
207 * to a trace of all actions performed on the object. */
208 HashTable<const void *, action_list_t *, uintptr_t, 4> *obj_map;
210 /** Per-object list of actions. Maps an object (i.e., memory location)
211 * to a trace of all actions performed on the object. */
212 HashTable<const void *, action_list_t *, uintptr_t, 4> *lock_waiters_map;
214 /** Per-object list of actions. Maps an object (i.e., memory location)
215 * to a trace of all actions performed on the object. */
216 HashTable<const void *, action_list_t *, uintptr_t, 4> *condvar_waiters_map;
218 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > *obj_thrd_map;
219 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
220 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
223 * List of pending release sequences. Release sequences might be
224 * determined lazily as promises are fulfilled and modification orders
225 * are established. Each entry in the list may only be partially
226 * filled, depending on its pending status.
228 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
230 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
231 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_fence_release;
232 NodeStack *node_stack;
234 /** Private data members that should be snapshotted. They are grouped
235 * together for efficiency and maintainability. */
236 struct model_snapshot_members *priv;
238 /** A special model-checker Thread; used for associating with
239 * model-checker-related ModelAcitons */
240 Thread *model_thread;
243 * @brief The modification order graph
245 * A directed acyclic graph recording observations of the modification
246 * order on all the atomic objects in the system. This graph should
247 * never contain any cycles, as that represents a violation of the
248 * memory model (total ordering). This graph really consists of many
249 * disjoint (unconnected) subgraphs, each graph corresponding to a
250 * separate ordering on a distinct object.
252 * The edges in this graph represent the "ordered before" relation,
253 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
256 CycleGraph *mo_graph;
258 /** @brief The cumulative execution stats */
259 struct execution_stats stats;
262 void print_infeasibility(const char *prefix) const;
263 bool is_feasible_prefix_ignore_relseq() const;
264 bool is_infeasible() const;
265 bool is_deadlocked() const;
266 bool is_complete_execution() const;
267 bool have_bug_reports() const;
268 void print_bugs() const;
269 void print_execution(bool printbugs) const;
270 void print_stats() const;
272 friend void user_main_wrapper();
275 extern ModelChecker *model;
277 #endif /* __MODEL_H__ */