2 * @brief Core model checker.
15 #include "hashtable.h"
16 #include "workqueue.h"
18 #include "modeltypes.h"
20 /* Forward declaration */
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
46 struct PendingFutureValue {
52 * Structure for holding small ModelChecker members that should be snapshotted
54 struct model_snapshot_members {
55 ModelAction *current_action;
56 unsigned int next_thread_id;
57 modelclock_t used_sequence_numbers;
59 ModelAction *next_backtrack;
62 /** @brief Records information regarding a single pending release sequence */
64 /** @brief The acquire operation */
66 /** @brief The head of the RMW chain from which 'acquire' reads; may be
67 * equal to 'release' */
68 const ModelAction *rf;
69 /** @brief The head of the potential longest release sequence chain */
70 const ModelAction *release;
71 /** @brief The write(s) that may break the release sequence */
72 std::vector<const ModelAction *> writes;
75 /** @brief The central structure for model-checking */
78 ModelChecker(struct model_params params);
81 /** @returns the context for the main model-checking system thread */
82 ucontext_t * get_system_context() { return &system_context; }
84 /** Prints an execution summary with trace information. */
86 #if SUPPORT_MOD_ORDER_DUMP
87 void dumpGraph(char *filename);
90 void add_thread(Thread *t);
91 void remove_thread(Thread *t);
92 Thread * get_thread(thread_id_t tid) const;
93 Thread * get_thread(ModelAction *act) const;
95 thread_id_t get_next_id();
96 unsigned int get_num_threads() const;
97 Thread * get_current_thread();
99 int switch_to_master(ModelAction *act);
100 ClockVector * get_cv(thread_id_t tid);
101 ModelAction * get_parent_action(thread_id_t tid);
102 bool next_execution();
104 bool isfeasibleotherthanRMW();
105 bool isfinalfeasible();
106 void check_promises_thread_disabled();
107 void mo_check_promises(thread_id_t tid, const ModelAction *write);
108 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
109 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
110 void finish_execution();
111 bool isfeasibleprefix();
112 void set_assert() {asserted=true;}
113 bool is_deadlocked() const;
115 /** @brief Alert the model-checker that an incorrectly-ordered
116 * synchronization was made */
117 void set_bad_synchronization() { bad_synchronization = true; }
119 const model_params params;
120 Scheduler * get_scheduler() { return scheduler;}
121 Node * get_curr_node();
125 /** The scheduler to use: tracks the running/ready Threads */
126 Scheduler *scheduler;
128 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
129 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
130 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
131 bool has_asserted() {return asserted;}
132 void reset_asserted() {asserted=false;}
134 int num_feasible_executions;
135 bool promises_expired();
136 void execute_sleep_set();
137 void wake_up_sleeping_actions(ModelAction * curr);
138 modelclock_t get_next_seq_num();
141 * Stores the ModelAction for the current thread action. Call this
142 * immediately before switching from user- to system-context to pass
144 * @param act The ModelAction created by the user-thread action
146 void set_current_action(ModelAction *act) { priv->current_action = act; }
147 Thread * check_current_action(ModelAction *curr);
148 bool initialize_curr_action(ModelAction **curr);
149 bool process_read(ModelAction *curr, bool second_part_of_rmw);
150 bool process_write(ModelAction *curr);
151 bool process_mutex(ModelAction *curr);
152 bool process_thread_action(ModelAction *curr);
153 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
154 bool check_action_enabled(ModelAction *curr);
158 void check_recency(ModelAction *curr, const ModelAction *rf);
159 ModelAction * get_last_conflict(ModelAction *act);
160 void set_backtracking(ModelAction *act);
161 Thread * get_next_thread(ModelAction *curr);
162 ModelAction * get_next_backtrack();
163 void reset_to_initial_state();
164 bool resolve_promises(ModelAction *curr);
165 void compute_promises(ModelAction *curr);
166 void compute_relseq_breakwrites(ModelAction *curr);
168 void check_curr_backtracking(ModelAction * curr);
169 void add_action_to_lists(ModelAction *act);
170 ModelAction * get_last_action(thread_id_t tid) const;
171 ModelAction * get_last_seq_cst(ModelAction *curr) const;
172 ModelAction * get_last_unlock(ModelAction *curr) const;
173 void build_reads_from_past(ModelAction *curr);
174 ModelAction * process_rmw(ModelAction *curr);
175 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
176 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
177 bool w_modification_order(ModelAction *curr);
178 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
179 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
181 ModelAction *diverge;
182 ModelAction *earliest_diverge;
184 ucontext_t system_context;
185 action_list_t *action_trace;
186 HashTable<int, Thread *, int> *thread_map;
188 /** Per-object list of actions. Maps an object (i.e., memory location)
189 * to a trace of all actions performed on the object. */
190 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
192 /** Per-object list of actions. Maps an object (i.e., memory location)
193 * to a trace of all actions performed on the object. */
194 HashTable<const void *, action_list_t, uintptr_t, 4> *lock_waiters_map;
196 /** Per-object list of actions. Maps an object (i.e., memory location)
197 * to a trace of all actions performed on the object. */
198 HashTable<const void *, action_list_t, uintptr_t, 4> *condvar_waiters_map;
200 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
201 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
202 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
205 * List of pending release sequences. Release sequences might be
206 * determined lazily as promises are fulfilled and modification orders
207 * are established. Each entry in the list may only be partially
208 * filled, depending on its pending status.
210 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
212 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
213 NodeStack *node_stack;
215 /** Private data members that should be snapshotted. They are grouped
216 * together for efficiency and maintainability. */
217 struct model_snapshot_members *priv;
219 /** A special model-checker Thread; used for associating with
220 * model-checker-related ModelAcitons */
221 Thread *model_thread;
224 * @brief The modification order graph
226 * A directed acyclic graph recording observations of the modification
227 * order on all the atomic objects in the system. This graph should
228 * never contain any cycles, as that represents a violation of the
229 * memory model (total ordering). This graph really consists of many
230 * disjoint (unconnected) subgraphs, each graph corresponding to a
231 * separate ordering on a distinct object.
233 * The edges in this graph represent the "ordered before" relation,
234 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
237 CycleGraph *mo_graph;
241 /** @brief Incorrectly-ordered synchronization was made */
242 bool bad_synchronization;
245 extern ModelChecker *model;
247 #endif /* __MODEL_H__ */