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;
52 struct PendingFutureValue {
57 /** @brief Records information regarding a single pending release sequence */
59 /** @brief The acquire operation */
61 /** @brief The head of the RMW chain from which 'acquire' reads; may be
62 * equal to 'release' */
63 const ModelAction *rf;
64 /** @brief The head of the potential longest release sequence chain */
65 const ModelAction *release;
66 /** @brief The write(s) that may break the release sequence */
67 std::vector<const ModelAction *> writes;
70 /** @brief The central structure for model-checking */
73 ModelChecker(struct model_params params);
76 /** @returns the context for the main model-checking system thread */
77 ucontext_t * get_system_context() { return &system_context; }
79 /** Prints an execution summary with trace information. */
81 #if SUPPORT_MOD_ORDER_DUMP
82 void dumpGraph(char *filename);
85 void add_thread(Thread *t);
86 void remove_thread(Thread *t);
87 Thread * get_thread(thread_id_t tid) const;
88 Thread * get_thread(ModelAction *act) const;
90 bool is_enabled(Thread *t) const;
91 bool is_enabled(thread_id_t tid) const;
93 thread_id_t get_next_id();
94 unsigned int get_num_threads() const;
95 Thread * get_current_thread();
97 int switch_to_master(ModelAction *act);
98 ClockVector * get_cv(thread_id_t tid);
99 ModelAction * get_parent_action(thread_id_t tid);
100 bool next_execution();
101 bool isfeasible() const;
102 bool isfeasibleotherthanRMW() const;
103 bool isfinalfeasible() const;
104 void check_promises_thread_disabled();
105 void mo_check_promises(thread_id_t tid, const ModelAction *write);
106 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
107 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
108 void finish_execution();
109 bool isfeasibleprefix() const;
111 void assert_bug(const char *msg, bool user_thread = false, bool immediate = false);
112 void assert_bug(bool user_thread = true);
113 void assert_bug_immediate(const char *msg);
115 void set_assert() {asserted=true;}
116 bool is_deadlocked() const;
117 bool is_complete_execution() const;
119 /** @brief Alert the model-checker that an incorrectly-ordered
120 * synchronization was made */
121 void set_bad_synchronization() { bad_synchronization = true; }
123 const model_params params;
124 Node * get_curr_node();
128 /** The scheduler to use: tracks the running/ready Threads */
129 Scheduler *scheduler;
131 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
132 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
133 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
134 bool has_asserted() {return asserted;}
135 void reset_asserted() {asserted=false;}
137 int num_feasible_executions;
138 bool promises_expired() const;
139 void execute_sleep_set();
140 void wake_up_sleeping_actions(ModelAction * curr);
141 modelclock_t get_next_seq_num();
143 void set_current_action(ModelAction *act);
144 Thread * check_current_action(ModelAction *curr);
145 bool initialize_curr_action(ModelAction **curr);
146 bool process_read(ModelAction *curr, bool second_part_of_rmw);
147 bool process_write(ModelAction *curr);
148 bool process_mutex(ModelAction *curr);
149 bool process_thread_action(ModelAction *curr);
150 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
151 bool check_action_enabled(ModelAction *curr);
155 void check_recency(ModelAction *curr, const ModelAction *rf);
156 ModelAction * get_last_conflict(ModelAction *act);
157 void set_backtracking(ModelAction *act);
158 Thread * get_next_thread(ModelAction *curr);
159 ModelAction * get_next_backtrack();
160 void reset_to_initial_state();
161 bool resolve_promises(ModelAction *curr);
162 void compute_promises(ModelAction *curr);
163 void compute_relseq_breakwrites(ModelAction *curr);
165 void check_curr_backtracking(ModelAction * curr);
166 void add_action_to_lists(ModelAction *act);
167 ModelAction * get_last_action(thread_id_t tid) const;
168 ModelAction * get_last_seq_cst(ModelAction *curr) const;
169 ModelAction * get_last_unlock(ModelAction *curr) const;
170 void build_reads_from_past(ModelAction *curr);
171 ModelAction * process_rmw(ModelAction *curr);
172 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
173 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
174 bool w_modification_order(ModelAction *curr);
175 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
176 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
178 ModelAction *diverge;
179 ModelAction *earliest_diverge;
181 ucontext_t system_context;
182 action_list_t *action_trace;
183 HashTable<int, Thread *, int> *thread_map;
185 /** Per-object list of actions. Maps an object (i.e., memory location)
186 * to a trace of all actions performed on the object. */
187 HashTable<const void *, action_list_t *, uintptr_t, 4> *obj_map;
189 /** Per-object list of actions. Maps an object (i.e., memory location)
190 * to a trace of all actions performed on the object. */
191 HashTable<const void *, action_list_t *, uintptr_t, 4> *lock_waiters_map;
193 /** Per-object list of actions. Maps an object (i.e., memory location)
194 * to a trace of all actions performed on the object. */
195 HashTable<const void *, action_list_t *, uintptr_t, 4> *condvar_waiters_map;
197 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > *obj_thrd_map;
198 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
199 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
202 * List of pending release sequences. Release sequences might be
203 * determined lazily as promises are fulfilled and modification orders
204 * are established. Each entry in the list may only be partially
205 * filled, depending on its pending status.
207 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
209 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
210 NodeStack *node_stack;
212 /** Private data members that should be snapshotted. They are grouped
213 * together for efficiency and maintainability. */
214 struct model_snapshot_members *priv;
216 /** A special model-checker Thread; used for associating with
217 * model-checker-related ModelAcitons */
218 Thread *model_thread;
221 * @brief The modification order graph
223 * A directed acyclic graph recording observations of the modification
224 * order on all the atomic objects in the system. This graph should
225 * never contain any cycles, as that represents a violation of the
226 * memory model (total ordering). This graph really consists of many
227 * disjoint (unconnected) subgraphs, each graph corresponding to a
228 * separate ordering on a distinct object.
230 * The edges in this graph represent the "ordered before" relation,
231 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
234 CycleGraph *mo_graph;
238 /** @brief Incorrectly-ordered synchronization was made */
239 bool bad_synchronization;
241 bool have_bug_reports() const;
242 void print_bugs() const;
245 extern ModelChecker *model;
247 #endif /* __MODEL_H__ */