2 * @brief Core model checker.
12 #include "hashtable.h"
13 #include "workqueue.h"
15 #include "modeltypes.h"
16 #include "stl-model.h"
19 /* Forward declaration */
28 struct model_snapshot_members;
30 /** @brief Shorthand for a list of release sequence heads */
31 typedef ModelVector<const ModelAction *> rel_heads_list_t;
33 typedef SnapList<ModelAction *> action_list_t;
36 * Model checker parameter structure. Holds run-time configuration options for
43 bool sc_trace_analysis;
44 unsigned int fairwindow;
45 unsigned int enabledcount;
47 unsigned int uninitvalue;
49 /** @brief Maximum number of future values that can be sent to the same
53 /** @brief Only generate a new future value/expiration pair if the
54 * expiration time exceeds the existing one by more than the slop
56 unsigned int expireslop;
58 /** @brief Verbosity (0 = quiet; 1 = noisy) */
61 /** @brief Command-line argument count to pass to user program */
64 /** @brief Command-line arguments to pass to user program */
68 /** @brief Model checker execution stats */
69 struct execution_stats {
70 int num_total; /**< @brief Total number of executions */
71 int num_infeasible; /**< @brief Number of infeasible executions */
72 int num_buggy_executions; /** @brief Number of buggy executions */
73 int num_complete; /**< @brief Number of feasible, non-buggy, complete executions */
74 int num_redundant; /**< @brief Number of redundant, aborted executions */
77 struct PendingFutureValue {
78 PendingFutureValue(ModelAction *writer, ModelAction *reader) :
79 writer(writer), reader(reader)
81 const ModelAction *writer;
85 /** @brief Records information regarding a single pending release sequence */
87 /** @brief The acquire operation */
89 /** @brief The read operation that may read from a release sequence;
90 * may be the same as acquire, or else an earlier action in the same
91 * thread (i.e., when 'acquire' is a fence-acquire) */
92 const ModelAction *read;
93 /** @brief The head of the RMW chain from which 'read' reads; may be
94 * equal to 'release' */
95 const ModelAction *rf;
96 /** @brief The head of the potential longest release sequence chain */
97 const ModelAction *release;
98 /** @brief The write(s) that may break the release sequence */
99 SnapVector<const ModelAction *> writes;
102 /** @brief The central structure for model-checking */
105 ModelChecker(struct model_params params);
110 /** @returns the context for the main model-checking system thread */
111 ucontext_t * get_system_context() { return &system_context; }
113 void print_summary() const;
114 #if SUPPORT_MOD_ORDER_DUMP
115 void dumpGraph(char *filename) const;
118 Thread * get_thread(thread_id_t tid) const;
119 Thread * get_thread(const ModelAction *act) const;
120 int get_promise_number(const Promise *promise) const;
122 bool is_enabled(Thread *t) const;
123 bool is_enabled(thread_id_t tid) const;
125 thread_id_t get_next_id();
126 unsigned int get_num_threads() const;
127 Thread * get_current_thread() const;
129 void switch_from_master(Thread *thread);
130 uint64_t switch_to_master(ModelAction *act);
131 ClockVector * get_cv(thread_id_t tid) const;
132 ModelAction * get_parent_action(thread_id_t tid) const;
133 void check_promises_thread_disabled();
134 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector *merge_cv);
135 bool isfeasibleprefix() const;
137 bool assert_bug(const char *msg, ...);
138 void assert_user_bug(const char *msg);
140 const model_params params;
141 Node * get_curr_node() const;
142 void add_trace_analysis(Trace_Analysis * a) {
143 trace_analyses->push_back(a);
148 /** The scheduler to use: tracks the running/ready Threads */
149 Scheduler * const scheduler;
151 void add_thread(Thread *t);
153 bool sleep_can_read_from(ModelAction *curr, const ModelAction *write);
154 bool thin_air_constraint_may_allow(const ModelAction *writer, const ModelAction *reader) const;
155 bool mo_may_allow(const ModelAction *writer, const ModelAction *reader);
156 bool promises_may_allow(const ModelAction *writer, const ModelAction *reader) const;
157 bool has_asserted() const;
159 void set_bad_synchronization();
160 bool promises_expired() const;
161 void execute_sleep_set();
162 bool should_wake_up(const ModelAction *curr, const Thread *thread) const;
163 void wake_up_sleeping_actions(ModelAction *curr);
164 modelclock_t get_next_seq_num();
166 bool next_execution();
167 ModelAction * check_current_action(ModelAction *curr);
168 bool initialize_curr_action(ModelAction **curr);
169 bool process_read(ModelAction *curr);
170 bool process_write(ModelAction *curr);
171 bool process_fence(ModelAction *curr);
172 bool process_mutex(ModelAction *curr);
173 bool process_thread_action(ModelAction *curr);
174 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
175 bool read_from(ModelAction *act, const ModelAction *rf);
176 bool check_action_enabled(ModelAction *curr);
178 Thread * take_step(ModelAction *curr);
179 bool should_terminate_execution();
181 template <typename T>
182 bool check_recency(ModelAction *curr, const T *rf) const;
184 template <typename T, typename U>
185 bool should_read_instead(const ModelAction *curr, const T *rf, const U *other_rf) const;
187 ModelAction * get_last_fence_conflict(ModelAction *act) const;
188 ModelAction * get_last_conflict(ModelAction *act) const;
189 void set_backtracking(ModelAction *act);
190 Thread * action_select_next_thread(const ModelAction *curr) const;
191 Thread * get_next_thread();
192 bool set_latest_backtrack(ModelAction *act);
193 ModelAction * get_next_backtrack();
194 void reset_to_initial_state();
195 Promise * pop_promise_to_resolve(const ModelAction *curr);
196 bool resolve_promise(ModelAction *curr, Promise *promise);
197 void compute_promises(ModelAction *curr);
198 void compute_relseq_breakwrites(ModelAction *curr);
200 void mo_check_promises(const ModelAction *act, bool is_read_check);
201 void thread_blocking_check_promises(Thread *blocker, Thread *waiting);
203 void check_curr_backtracking(ModelAction *curr);
204 void add_action_to_lists(ModelAction *act);
205 ModelAction * get_last_action(thread_id_t tid) const;
206 ModelAction * get_last_fence_release(thread_id_t tid) const;
207 ModelAction * get_last_seq_cst_write(ModelAction *curr) const;
208 ModelAction * get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) const;
209 ModelAction * get_last_unlock(ModelAction *curr) const;
210 void build_may_read_from(ModelAction *curr);
211 ModelAction * process_rmw(ModelAction *curr);
213 template <typename rf_type>
214 bool r_modification_order(ModelAction *curr, const rf_type *rf);
216 bool w_modification_order(ModelAction *curr, ModelVector<ModelAction *> *send_fv);
217 void get_release_seq_heads(ModelAction *acquire, ModelAction *read, rel_heads_list_t *release_heads);
218 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
219 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
220 void add_future_value(const ModelAction *writer, ModelAction *reader);
222 ModelAction * get_uninitialized_action(const ModelAction *curr) const;
224 ModelAction *diverge;
225 ModelAction *earliest_diverge;
227 ucontext_t system_context;
228 action_list_t * const action_trace;
229 HashTable<int, Thread *, int> * const thread_map;
231 /** Per-object list of actions. Maps an object (i.e., memory location)
232 * to a trace of all actions performed on the object. */
233 HashTable<const void *, action_list_t *, uintptr_t, 4> * const obj_map;
235 /** Per-object list of actions. Maps an object (i.e., memory location)
236 * to a trace of all actions performed on the object. */
237 HashTable<const void *, action_list_t *, uintptr_t, 4> * const condvar_waiters_map;
239 HashTable<void *, SnapVector<action_list_t> *, uintptr_t, 4 > * const obj_thrd_map;
240 SnapVector<Promise *> * const promises;
241 SnapVector<struct PendingFutureValue> * const futurevalues;
244 * List of pending release sequences. Release sequences might be
245 * determined lazily as promises are fulfilled and modification orders
246 * are established. Each entry in the list may only be partially
247 * filled, depending on its pending status.
249 SnapVector<struct release_seq *> * const pending_rel_seqs;
251 SnapVector<ModelAction *> * const thrd_last_action;
252 SnapVector<ModelAction *> * const thrd_last_fence_release;
253 NodeStack * const node_stack;
254 ModelVector<Trace_Analysis *> * trace_analyses;
257 /** Private data members that should be snapshotted. They are grouped
258 * together for efficiency and maintainability. */
259 struct model_snapshot_members * const priv;
261 /** A special model-checker Thread; used for associating with
262 * model-checker-related ModelAcitons */
263 Thread *model_thread;
266 * @brief The modification order graph
268 * A directed acyclic graph recording observations of the modification
269 * order on all the atomic objects in the system. This graph should
270 * never contain any cycles, as that represents a violation of the
271 * memory model (total ordering). This graph really consists of many
272 * disjoint (unconnected) subgraphs, each graph corresponding to a
273 * separate ordering on a distinct object.
275 * The edges in this graph represent the "ordered before" relation,
276 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
279 CycleGraph * const mo_graph;
281 /** @brief The cumulative execution stats */
282 struct execution_stats stats;
284 void run_trace_analyses();
285 void print_infeasibility(const char *prefix) const;
286 bool is_feasible_prefix_ignore_relseq() const;
287 bool is_infeasible() const;
288 bool is_deadlocked() const;
289 bool is_complete_execution() const;
290 bool have_bug_reports() const;
291 void print_bugs() const;
292 void print_execution(bool printbugs) const;
293 void print_stats() const;
295 friend void user_main_wrapper();
298 extern ModelChecker *model;
300 #endif /* __MODEL_H__ */