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
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;
51 struct PendingFutureValue {
57 * Structure for holding small ModelChecker members that should be snapshotted
59 struct model_snapshot_members {
60 ModelAction *current_action;
61 unsigned int next_thread_id;
62 modelclock_t used_sequence_numbers;
64 ModelAction *next_backtrack;
67 /** @brief Records information regarding a single pending release sequence */
69 /** @brief The acquire operation */
71 /** @brief The head of the RMW chain from which 'acquire' reads; may be
72 * equal to 'release' */
73 const ModelAction *rf;
74 /** @brief The head of the potential longest release sequence chain */
75 const ModelAction *release;
76 /** @brief The write(s) that may break the release sequence */
77 std::vector<const ModelAction *> writes;
80 /** @brief The central structure for model-checking */
83 ModelChecker(struct model_params params);
86 /** @returns the context for the main model-checking system thread */
87 ucontext_t * get_system_context() { return &system_context; }
89 /** Prints an execution summary with trace information. */
91 #if SUPPORT_MOD_ORDER_DUMP
92 void dumpGraph(char *filename);
95 void add_thread(Thread *t);
96 void remove_thread(Thread *t);
97 Thread * get_thread(thread_id_t tid) const;
98 Thread * get_thread(ModelAction *act) const;
100 thread_id_t get_next_id();
101 unsigned int get_num_threads() const;
102 Thread * get_current_thread();
104 int switch_to_master(ModelAction *act);
105 ClockVector * get_cv(thread_id_t tid);
106 ModelAction * get_parent_action(thread_id_t tid);
107 bool next_execution();
109 bool isfeasibleotherthanRMW();
110 bool isfinalfeasible();
111 void check_promises_thread_disabled();
112 void mo_check_promises(thread_id_t tid, const ModelAction *write);
113 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
114 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
115 void finish_execution();
116 bool isfeasibleprefix();
117 void set_assert() {asserted=true;}
118 bool is_deadlocked() const;
120 /** @brief Alert the model-checker that an incorrectly-ordered
121 * synchronization was made */
122 void set_bad_synchronization() { bad_synchronization = true; }
124 const model_params params;
125 Scheduler * get_scheduler() { return scheduler;}
126 Node * get_curr_node();
130 /** The scheduler to use: tracks the running/ready Threads */
131 Scheduler *scheduler;
133 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
134 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
135 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
136 bool has_asserted() {return asserted;}
137 void reset_asserted() {asserted=false;}
139 int num_feasible_executions;
140 bool promises_expired();
141 void execute_sleep_set();
142 void wake_up_sleeping_actions(ModelAction * curr);
143 modelclock_t get_next_seq_num();
146 * Stores the ModelAction for the current thread action. Call this
147 * immediately before switching from user- to system-context to pass
149 * @param act The ModelAction created by the user-thread action
151 void set_current_action(ModelAction *act) { priv->current_action = act; }
152 Thread * check_current_action(ModelAction *curr);
153 bool initialize_curr_action(ModelAction **curr);
154 bool process_read(ModelAction *curr, bool second_part_of_rmw);
155 bool process_write(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 check_action_enabled(ModelAction *curr);
163 void check_recency(ModelAction *curr, const ModelAction *rf);
164 ModelAction * get_last_conflict(ModelAction *act);
165 void set_backtracking(ModelAction *act);
166 Thread * get_next_thread(ModelAction *curr);
167 ModelAction * get_next_backtrack();
168 void reset_to_initial_state();
169 bool resolve_promises(ModelAction *curr);
170 void compute_promises(ModelAction *curr);
171 void compute_relseq_breakwrites(ModelAction *curr);
173 void check_curr_backtracking(ModelAction * curr);
174 void add_action_to_lists(ModelAction *act);
175 ModelAction * get_last_action(thread_id_t tid) const;
176 ModelAction * get_last_seq_cst(ModelAction *curr) const;
177 ModelAction * get_last_unlock(ModelAction *curr) const;
178 void build_reads_from_past(ModelAction *curr);
179 ModelAction * process_rmw(ModelAction *curr);
180 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
181 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
182 bool w_modification_order(ModelAction *curr);
183 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
184 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
186 ModelAction *diverge;
187 ModelAction *earliest_diverge;
189 ucontext_t system_context;
190 action_list_t *action_trace;
191 HashTable<int, Thread *, int> *thread_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> *obj_map;
197 /** Per-object list of actions. Maps an object (i.e., memory location)
198 * to a trace of all actions performed on the object. */
199 HashTable<const void *, action_list_t, uintptr_t, 4> *lock_waiters_map;
201 /** Per-object list of actions. Maps an object (i.e., memory location)
202 * to a trace of all actions performed on the object. */
203 HashTable<const void *, action_list_t, uintptr_t, 4> *condvar_waiters_map;
205 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
206 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
207 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
210 * List of pending release sequences. Release sequences might be
211 * determined lazily as promises are fulfilled and modification orders
212 * are established. Each entry in the list may only be partially
213 * filled, depending on its pending status.
215 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
217 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
218 NodeStack *node_stack;
220 /** Private data members that should be snapshotted. They are grouped
221 * together for efficiency and maintainability. */
222 struct model_snapshot_members *priv;
224 /** A special model-checker Thread; used for associating with
225 * model-checker-related ModelAcitons */
226 Thread *model_thread;
229 * @brief The modification order graph
231 * A directed acyclic graph recording observations of the modification
232 * order on all the atomic objects in the system. This graph should
233 * never contain any cycles, as that represents a violation of the
234 * memory model (total ordering). This graph really consists of many
235 * disjoint (unconnected) subgraphs, each graph corresponding to a
236 * separate ordering on a distinct object.
238 * The edges in this graph represent the "ordered before" relation,
239 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
242 CycleGraph *mo_graph;
246 /** @brief Incorrectly-ordered synchronization was made */
247 bool bad_synchronization;
250 extern ModelChecker *model;
252 #endif /* __MODEL_H__ */