2 * @brief Core model checker.
15 #include "libthreads.h"
18 #include "clockvector.h"
19 #include "hashtable.h"
20 #include "workqueue.h"
23 /* Forward declaration */
28 /** @brief Shorthand for a list of release sequence heads */
29 typedef std::vector< const ModelAction *, MyAlloc<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 struct PendingFutureValue {
44 modelclock_t expiration;
49 * Structure for holding small ModelChecker members that should be snapshotted
51 struct model_snapshot_members {
52 ModelAction *current_action;
54 modelclock_t used_sequence_numbers;
56 ModelAction *next_backtrack;
59 /** @brief The central structure for model-checking */
62 ModelChecker(struct model_params params);
65 /** @returns the context for the main model-checking system thread */
66 ucontext_t * get_system_context() { return &system_context; }
68 /** Prints an execution summary with trace information. */
70 #if SUPPORT_MOD_ORDER_DUMP
71 void dumpGraph(char *filename);
74 void add_thread(Thread *t);
75 void remove_thread(Thread *t);
76 Thread * get_thread(thread_id_t tid) { return thread_map->get(id_to_int(tid)); }
77 Thread * get_thread(ModelAction *act) { return get_thread(act->get_tid()); }
79 thread_id_t get_next_id();
80 int get_num_threads();
81 modelclock_t get_next_seq_num();
83 /** @return The currently executing Thread. */
84 Thread * get_current_thread() { return scheduler->get_current_thread(); }
86 int switch_to_master(ModelAction *act);
87 ClockVector * get_cv(thread_id_t tid);
88 ModelAction * get_parent_action(thread_id_t tid);
89 bool next_execution();
91 bool isfeasibleotherthanRMW();
92 bool isfinalfeasible();
93 void check_promises(ClockVector *old_cv, ClockVector * merge_cv);
94 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
95 void finish_execution();
96 bool isfeasibleprefix();
97 void set_assert() {asserted=true;}
99 /** @brief Alert the model-checker that an incorrectly-ordered
100 * synchronization was made */
101 void set_bad_synchronization() { bad_synchronization = true; }
103 const model_params params;
107 /** The scheduler to use: tracks the running/ready Threads */
108 Scheduler *scheduler;
110 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
111 bool has_asserted() {return asserted;}
112 void reset_asserted() {asserted=false;}
114 int num_feasible_executions;
115 bool promises_expired();
118 * Stores the ModelAction for the current thread action. Call this
119 * immediately before switching from user- to system-context to pass
121 * @param act The ModelAction created by the user-thread action
123 void set_current_action(ModelAction *act) { priv->current_action = act; }
124 Thread * check_current_action(ModelAction *curr);
125 ModelAction * initialize_curr_action(ModelAction *curr);
126 bool process_read(ModelAction *curr, bool second_part_of_rmw);
127 bool process_write(ModelAction *curr);
128 bool process_mutex(ModelAction *curr);
129 bool process_thread_action(ModelAction *curr);
130 bool check_action_enabled(ModelAction *curr);
134 void check_recency(ModelAction *curr, const ModelAction *rf);
135 ModelAction * get_last_conflict(ModelAction *act);
136 void set_backtracking(ModelAction *act);
137 Thread * get_next_thread(ModelAction *curr);
138 ModelAction * get_next_backtrack();
139 void reset_to_initial_state();
140 bool resolve_promises(ModelAction *curr);
141 void compute_promises(ModelAction *curr);
143 void check_curr_backtracking(ModelAction * curr);
144 void add_action_to_lists(ModelAction *act);
145 ModelAction * get_last_action(thread_id_t tid) const;
146 ModelAction * get_last_seq_cst(ModelAction *curr) const;
147 ModelAction * get_last_unlock(ModelAction *curr) const;
148 void build_reads_from_past(ModelAction *curr);
149 ModelAction * process_rmw(ModelAction *curr);
150 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
151 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
152 bool w_modification_order(ModelAction *curr);
153 bool release_seq_head(const ModelAction *rf, rel_heads_list_t *release_heads) const;
154 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
156 ModelAction *diverge;
157 ModelAction *earliest_diverge;
159 ucontext_t system_context;
160 action_list_t *action_trace;
161 HashTable<int, Thread *, int> *thread_map;
163 /** Per-object list of actions. Maps an object (i.e., memory location)
164 * to a trace of all actions performed on the object. */
165 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
167 /** Per-object list of actions. Maps an object (i.e., memory location)
168 * to a trace of all actions performed on the object. */
169 HashTable<const void *, action_list_t, uintptr_t, 4> *lock_waiters_map;
171 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
172 std::vector<Promise *> *promises;
173 std::vector<struct PendingFutureValue> *futurevalues;
176 * List of acquire actions that might synchronize with one or more
177 * release sequence. Release sequences might be determined lazily as
178 * promises are fulfilled and modification orders are established. Each
179 * ModelAction in this list must be an acquire operation.
181 std::vector<ModelAction *> *pending_acq_rel_seq;
183 std::vector<ModelAction *> *thrd_last_action;
184 NodeStack *node_stack;
186 /** Private data members that should be snapshotted. They are grouped
187 * together for efficiency and maintainability. */
188 struct model_snapshot_members *priv;
191 * @brief The modification order graph
193 * A directed acyclic graph recording observations of the modification
194 * order on all the atomic objects in the system. This graph should
195 * never contain any cycles, as that represents a violation of the
196 * memory model (total ordering). This graph really consists of many
197 * disjoint (unconnected) subgraphs, each graph corresponding to a
198 * separate ordering on a distinct object.
200 * The edges in this graph represent the "ordered before" relation,
201 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
204 CycleGraph *mo_graph;
208 /** @brief Incorrectly-ordered synchronization was made */
209 bool bad_synchronization;
212 extern ModelChecker *model;
214 #endif /* __MODEL_H__ */