2 * @brief Core model checker.
14 #include "hashtable.h"
15 #include "workqueue.h"
17 #include "modeltypes.h"
19 /* Forward declaration */
27 struct model_snapshot_members;
29 /** @brief Shorthand for a list of release sequence heads */
30 typedef std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > rel_heads_list_t;
32 typedef std::list< ModelAction *, SnapshotAlloc<ModelAction *> > action_list_t;
35 * Model checker parameter structure. Holds run-time configuration options for
42 unsigned int fairwindow;
43 unsigned int enabledcount;
46 /** @brief Maximum number of future values that can be sent to the same
50 /** @brief Only generate a new future value/expiration pair if the
51 * expiration time exceeds the existing one by more than the slop
53 unsigned int expireslop;
55 /** @brief Verbosity (0 = quiet; 1 = noisy) */
58 /** @brief Command-line argument count to pass to user program */
61 /** @brief Command-line arguments to pass to user program */
65 /** @brief Model checker execution stats */
66 struct execution_stats {
67 int num_total; /**< @brief Total number of executions */
68 int num_infeasible; /**< @brief Number of infeasible executions */
69 int num_buggy_executions; /** @brief Number of buggy executions */
70 int num_complete; /**< @brief Number of feasible, non-buggy, complete executions */
71 int num_redundant; /**< @brief Number of redundant, aborted executions */
74 struct PendingFutureValue {
75 PendingFutureValue(ModelAction *writer, ModelAction *act) : writer(writer), act(act) { }
76 const ModelAction *writer;
80 /** @brief Records information regarding a single pending release sequence */
82 /** @brief The acquire operation */
84 /** @brief The read operation that may read from a release sequence;
85 * may be the same as acquire, or else an earlier action in the same
86 * thread (i.e., when 'acquire' is a fence-acquire) */
87 const ModelAction *read;
88 /** @brief The head of the RMW chain from which 'read' reads; may be
89 * equal to 'release' */
90 const ModelAction *rf;
91 /** @brief The head of the potential longest release sequence chain */
92 const ModelAction *release;
93 /** @brief The write(s) that may break the release sequence */
94 std::vector<const ModelAction *> writes;
97 /** @brief The central structure for model-checking */
100 ModelChecker(struct model_params params);
105 /** @returns the context for the main model-checking system thread */
106 ucontext_t * get_system_context() { return &system_context; }
108 void print_summary() const;
109 #if SUPPORT_MOD_ORDER_DUMP
110 void dumpGraph(char *filename) const;
113 void add_thread(Thread *t);
114 void remove_thread(Thread *t);
115 Thread * get_thread(thread_id_t tid) const;
116 Thread * get_thread(const ModelAction *act) const;
117 int get_promise_number(const Promise *promise) const;
119 bool is_enabled(Thread *t) const;
120 bool is_enabled(thread_id_t tid) const;
122 thread_id_t get_next_id();
123 unsigned int get_num_threads() const;
124 Thread * get_current_thread() const;
126 void switch_from_master(Thread *thread);
127 uint64_t switch_to_master(ModelAction *act);
128 ClockVector * get_cv(thread_id_t tid) const;
129 ModelAction * get_parent_action(thread_id_t tid) const;
130 void check_promises_thread_disabled();
131 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector *merge_cv);
132 bool isfeasibleprefix() const;
134 bool assert_bug(const char *msg);
135 void assert_user_bug(const char *msg);
137 const model_params params;
138 Node * get_curr_node() const;
142 /** The scheduler to use: tracks the running/ready Threads */
143 Scheduler * const 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 void set_bad_synchronization();
151 bool promises_expired() const;
152 void execute_sleep_set();
153 bool should_wake_up(const ModelAction *curr, const Thread *thread) const;
154 void wake_up_sleeping_actions(ModelAction *curr);
155 modelclock_t get_next_seq_num();
157 bool next_execution();
158 ModelAction * check_current_action(ModelAction *curr);
159 bool initialize_curr_action(ModelAction **curr);
160 bool process_read(ModelAction *curr);
161 bool process_write(ModelAction *curr);
162 bool process_fence(ModelAction *curr);
163 bool process_mutex(ModelAction *curr);
164 bool process_thread_action(ModelAction *curr);
165 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
166 bool read_from(ModelAction *act, const ModelAction *rf);
167 bool check_action_enabled(ModelAction *curr);
169 Thread * take_step(ModelAction *curr);
171 template <typename T>
172 bool check_recency(ModelAction *curr, const T *rf) const;
174 template <typename T, typename U>
175 bool should_read_instead(const ModelAction *curr, const T *rf, const U *other_rf) const;
177 ModelAction * get_last_fence_conflict(ModelAction *act) const;
178 ModelAction * get_last_conflict(ModelAction *act) const;
179 void set_backtracking(ModelAction *act);
180 Thread * action_select_next_thread(const ModelAction *curr) const;
181 Thread * get_next_thread();
182 bool set_latest_backtrack(ModelAction *act);
183 ModelAction * get_next_backtrack();
184 void reset_to_initial_state();
185 int get_promise_to_resolve(const ModelAction *curr) const;
186 bool resolve_promise(ModelAction *curr, unsigned int promise_idx);
187 void compute_promises(ModelAction *curr);
188 void compute_relseq_breakwrites(ModelAction *curr);
190 void mo_check_promises(const ModelAction *act, bool is_read_check);
191 void thread_blocking_check_promises(Thread *blocker, Thread *waiting);
193 void check_curr_backtracking(ModelAction *curr);
194 void add_action_to_lists(ModelAction *act);
195 ModelAction * get_last_action(thread_id_t tid) const;
196 ModelAction * get_last_fence_release(thread_id_t tid) const;
197 ModelAction * get_last_seq_cst_write(ModelAction *curr) const;
198 ModelAction * get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) const;
199 ModelAction * get_last_unlock(ModelAction *curr) const;
200 void build_may_read_from(ModelAction *curr);
201 ModelAction * process_rmw(ModelAction *curr);
203 template <typename rf_type>
204 bool r_modification_order(ModelAction *curr, const rf_type *rf);
206 bool w_modification_order(ModelAction *curr, std::vector< ModelAction *, ModelAlloc<ModelAction *> > *send_fv);
207 void get_release_seq_heads(ModelAction *acquire, ModelAction *read, rel_heads_list_t *release_heads);
208 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
209 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
210 void add_future_value(const ModelAction *writer, ModelAction *reader);
212 ModelAction * new_uninitialized_action(void *location) const;
214 ModelAction *diverge;
215 ModelAction *earliest_diverge;
217 ucontext_t system_context;
218 action_list_t * const action_trace;
219 HashTable<int, Thread *, int> * const thread_map;
221 /** Per-object list of actions. Maps an object (i.e., memory location)
222 * to a trace of all actions performed on the object. */
223 HashTable<const void *, action_list_t *, uintptr_t, 4> * const obj_map;
225 /** Per-object list of actions. Maps an object (i.e., memory location)
226 * to a trace of all actions performed on the object. */
227 HashTable<const void *, action_list_t *, uintptr_t, 4> * const lock_waiters_map;
229 /** Per-object list of actions. Maps an object (i.e., memory location)
230 * to a trace of all actions performed on the object. */
231 HashTable<const void *, action_list_t *, uintptr_t, 4> * const condvar_waiters_map;
233 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > * const obj_thrd_map;
234 std::vector< Promise *, SnapshotAlloc<Promise *> > * const promises;
235 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > * const futurevalues;
238 * List of pending release sequences. Release sequences might be
239 * determined lazily as promises are fulfilled and modification orders
240 * are established. Each entry in the list may only be partially
241 * filled, depending on its pending status.
243 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > * const pending_rel_seqs;
245 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > * const thrd_last_action;
246 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > * const thrd_last_fence_release;
247 NodeStack * const node_stack;
249 /** Private data members that should be snapshotted. They are grouped
250 * together for efficiency and maintainability. */
251 struct model_snapshot_members * const priv;
253 /** A special model-checker Thread; used for associating with
254 * model-checker-related ModelAcitons */
255 Thread *model_thread;
258 * @brief The modification order graph
260 * A directed acyclic graph recording observations of the modification
261 * order on all the atomic objects in the system. This graph should
262 * never contain any cycles, as that represents a violation of the
263 * memory model (total ordering). This graph really consists of many
264 * disjoint (unconnected) subgraphs, each graph corresponding to a
265 * separate ordering on a distinct object.
267 * The edges in this graph represent the "ordered before" relation,
268 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
271 CycleGraph * const mo_graph;
273 /** @brief The cumulative execution stats */
274 struct execution_stats stats;
277 void print_infeasibility(const char *prefix) const;
278 bool is_feasible_prefix_ignore_relseq() const;
279 bool is_infeasible() const;
280 bool is_deadlocked() const;
281 bool is_circular_wait(const Thread *t) const;
282 bool is_complete_execution() const;
283 bool have_bug_reports() const;
284 void print_bugs() const;
285 void print_execution(bool printbugs) const;
286 void print_stats() const;
288 friend void user_main_wrapper();
291 extern ModelChecker *model;
293 #endif /* __MODEL_H__ */