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;
31 * Model checker parameter structure. Holds run-time configuration options for
37 unsigned int fairwindow;
38 unsigned int enabledcount;
41 /** @brief Maximum number of future values that can be sent to the same
45 /** @brief Only generate a new future value/expiration pair if the
46 * expiration time exceeds the existing one by more than the slop
48 unsigned int expireslop;
50 /** @brief Verbosity (0 = quiet; 1 = noisy) */
53 /** @brief Command-line argument count to pass to user program */
56 /** @brief Command-line arguments to pass to user program */
60 /** @brief Model checker execution stats */
61 struct execution_stats {
62 int num_total; /**< @brief Total number of executions */
63 int num_infeasible; /**< @brief Number of infeasible executions */
64 int num_buggy_executions; /** @brief Number of buggy executions */
65 int num_complete; /**< @brief Number of feasible, non-buggy, complete executions */
66 int num_redundant; /**< @brief Number of redundant, aborted executions */
69 struct PendingFutureValue {
74 /** @brief Records information regarding a single pending release sequence */
76 /** @brief The acquire operation */
78 /** @brief The read operation that may read from a release sequence;
79 * may be the same as acquire, or else an earlier action in the same
80 * thread (i.e., when 'acquire' is a fence-acquire) */
81 const ModelAction *read;
82 /** @brief The head of the RMW chain from which 'read' reads; may be
83 * equal to 'release' */
84 const ModelAction *rf;
85 /** @brief The head of the potential longest release sequence chain */
86 const ModelAction *release;
87 /** @brief The write(s) that may break the release sequence */
88 std::vector<const ModelAction *> writes;
91 /** @brief The central structure for model-checking */
94 ModelChecker(struct model_params params);
99 /** @returns the context for the main model-checking system thread */
100 ucontext_t * get_system_context() { return &system_context; }
102 void print_summary() const;
103 #if SUPPORT_MOD_ORDER_DUMP
104 void dumpGraph(char *filename) const;
107 void add_thread(Thread *t);
108 void remove_thread(Thread *t);
109 Thread * get_thread(thread_id_t tid) const;
110 Thread * get_thread(ModelAction *act) const;
112 bool is_enabled(Thread *t) const;
113 bool is_enabled(thread_id_t tid) const;
115 thread_id_t get_next_id();
116 unsigned int get_num_threads() const;
117 Thread * get_current_thread() const;
119 uint64_t switch_to_master(ModelAction *act);
120 ClockVector * get_cv(thread_id_t tid) const;
121 ModelAction * get_parent_action(thread_id_t tid) const;
122 void check_promises_thread_disabled();
123 void mo_check_promises(thread_id_t tid, const ModelAction *write);
124 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector *merge_cv);
125 bool isfeasibleprefix() const;
127 bool assert_bug(const char *msg);
128 void assert_user_bug(const char *msg);
130 const model_params params;
131 Node * get_curr_node() const;
135 /** The scheduler to use: tracks the running/ready Threads */
136 Scheduler *scheduler;
138 bool sleep_can_read_from(ModelAction *curr, const ModelAction *write);
139 bool thin_air_constraint_may_allow(const ModelAction *writer, const ModelAction *reader);
140 bool mo_may_allow(const ModelAction *writer, const ModelAction *reader);
141 bool has_asserted() const;
143 void set_bad_synchronization();
144 bool promises_expired() const;
145 void execute_sleep_set();
146 void wake_up_sleeping_actions(ModelAction *curr);
147 modelclock_t get_next_seq_num();
149 bool next_execution();
150 void set_current_action(ModelAction *act);
151 ModelAction * check_current_action(ModelAction *curr);
152 bool initialize_curr_action(ModelAction **curr);
153 bool process_read(ModelAction *curr, bool second_part_of_rmw);
154 bool process_write(ModelAction *curr);
155 bool process_fence(ModelAction *curr);
156 bool process_mutex(ModelAction *curr);
157 bool process_thread_action(ModelAction *curr);
158 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
159 bool read_from(ModelAction *act, const ModelAction *rf);
160 bool check_action_enabled(ModelAction *curr);
162 bool take_step(ModelAction *curr);
164 void check_recency(ModelAction *curr, const ModelAction *rf);
165 ModelAction * get_last_conflict(ModelAction *act);
166 void set_backtracking(ModelAction *act);
167 Thread * get_next_thread(ModelAction *curr);
168 bool set_latest_backtrack(ModelAction *act);
169 ModelAction * get_next_backtrack();
170 void reset_to_initial_state();
171 bool resolve_promises(ModelAction *curr);
172 void compute_promises(ModelAction *curr);
173 void compute_relseq_breakwrites(ModelAction *curr);
175 void check_curr_backtracking(ModelAction *curr);
176 void add_action_to_lists(ModelAction *act);
177 ModelAction * get_last_action(thread_id_t tid) const;
178 ModelAction * get_last_fence_release(thread_id_t tid) const;
179 ModelAction * get_last_seq_cst_write(ModelAction *curr) const;
180 ModelAction * get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) 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 void get_release_seq_heads(ModelAction *acquire, ModelAction *read, rel_heads_list_t *release_heads);
188 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
189 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
191 ModelAction * new_uninitialized_action(void *location) const;
193 ModelAction *diverge;
194 ModelAction *earliest_diverge;
196 ucontext_t system_context;
197 action_list_t *action_trace;
198 HashTable<int, Thread *, int> *thread_map;
200 /** Per-object list of actions. Maps an object (i.e., memory location)
201 * to a trace of all actions performed on the object. */
202 HashTable<const void *, action_list_t *, uintptr_t, 4> *obj_map;
204 /** Per-object list of actions. Maps an object (i.e., memory location)
205 * to a trace of all actions performed on the object. */
206 HashTable<const void *, action_list_t *, uintptr_t, 4> *lock_waiters_map;
208 /** Per-object list of actions. Maps an object (i.e., memory location)
209 * to a trace of all actions performed on the object. */
210 HashTable<const void *, action_list_t *, uintptr_t, 4> *condvar_waiters_map;
212 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > *obj_thrd_map;
213 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
214 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
217 * List of pending release sequences. Release sequences might be
218 * determined lazily as promises are fulfilled and modification orders
219 * are established. Each entry in the list may only be partially
220 * filled, depending on its pending status.
222 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
224 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
225 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_fence_release;
226 NodeStack *node_stack;
228 /** Private data members that should be snapshotted. They are grouped
229 * together for efficiency and maintainability. */
230 struct model_snapshot_members *priv;
232 /** A special model-checker Thread; used for associating with
233 * model-checker-related ModelAcitons */
234 Thread *model_thread;
237 * @brief The modification order graph
239 * A directed acyclic graph recording observations of the modification
240 * order on all the atomic objects in the system. This graph should
241 * never contain any cycles, as that represents a violation of the
242 * memory model (total ordering). This graph really consists of many
243 * disjoint (unconnected) subgraphs, each graph corresponding to a
244 * separate ordering on a distinct object.
246 * The edges in this graph represent the "ordered before" relation,
247 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
250 CycleGraph *mo_graph;
252 /** @brief The cumulative execution stats */
253 struct execution_stats stats;
256 bool is_feasible_prefix_ignore_relseq() const;
257 bool is_infeasible_ignoreRMW() const;
258 bool is_infeasible() const;
259 bool is_deadlocked() const;
260 bool is_complete_execution() const;
261 bool have_bug_reports() const;
262 void print_bugs() const;
263 void print_execution(bool printbugs) const;
264 void print_stats() const;
266 friend void user_main_wrapper();
269 extern ModelChecker *model;
271 #endif /* __MODEL_H__ */