2 * @brief Core model checker.
15 #include "libthreads.h"
18 #include "clockvector.h"
19 #include "hashtable.h"
20 #include "workqueue.h"
22 /* Forward declaration */
27 /** @brief Shorthand for a list of release sequence heads */
28 typedef std::vector< const ModelAction *, MyAlloc<const ModelAction *> > rel_heads_list_t;
31 * Model checker parameter structure. Holds run-time configuration options for
39 struct PendingFutureValue {
41 modelclock_t expiration;
46 * Structure for holding small ModelChecker members that should be snapshotted
48 struct model_snapshot_members {
49 ModelAction *current_action;
51 modelclock_t used_sequence_numbers;
53 ModelAction *next_backtrack;
56 /** @brief The central structure for model-checking */
59 ModelChecker(struct model_params params);
62 /** @returns the context for the main model-checking system thread */
63 ucontext_t * get_system_context() { return &system_context; }
65 /** Prints an execution summary with trace information. */
68 void add_thread(Thread *t);
69 void remove_thread(Thread *t);
70 Thread * get_thread(thread_id_t tid) { return thread_map->get(id_to_int(tid)); }
71 Thread * get_thread(ModelAction *act) { return get_thread(act->get_tid()); }
73 thread_id_t get_next_id();
74 int get_num_threads();
75 modelclock_t get_next_seq_num();
77 /** @return The currently executing Thread. */
78 Thread * get_current_thread() { return scheduler->get_current_thread(); }
80 int switch_to_master(ModelAction *act);
81 ClockVector * get_cv(thread_id_t tid);
82 ModelAction * get_parent_action(thread_id_t tid);
83 bool next_execution();
85 bool isfeasibleotherthanRMW();
86 bool isfinalfeasible();
87 void check_promises(ClockVector *old_cv, ClockVector * merge_cv);
88 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
89 void finish_execution();
90 bool isfeasibleprefix();
91 void set_assert() {asserted=true;}
95 /** The scheduler to use: tracks the running/ready Threads */
98 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
99 bool has_asserted() {return asserted;}
100 void reset_asserted() {asserted=false;}
102 int num_feasible_executions;
103 bool promises_expired();
104 const model_params params;
107 * Stores the ModelAction for the current thread action. Call this
108 * immediately before switching from user- to system-context to pass
110 * @param act The ModelAction created by the user-thread action
112 void set_current_action(ModelAction *act) { priv->current_action = act; }
113 Thread * check_current_action(ModelAction *curr);
114 ModelAction * initialize_curr_action(ModelAction *curr);
115 bool process_read(ModelAction *curr, bool second_part_of_rmw);
116 bool process_write(ModelAction *curr);
117 void process_mutex(ModelAction *curr);
118 bool check_action_enabled(ModelAction *curr);
122 void check_recency(ModelAction *curr);
123 ModelAction * get_last_conflict(ModelAction *act);
124 void set_backtracking(ModelAction *act);
125 Thread * get_next_thread(ModelAction *curr);
126 ModelAction * get_next_backtrack();
127 void reset_to_initial_state();
128 bool resolve_promises(ModelAction *curr);
129 void compute_promises(ModelAction *curr);
131 void check_curr_backtracking(ModelAction * curr);
132 void add_action_to_lists(ModelAction *act);
133 ModelAction * get_last_action(thread_id_t tid) const;
134 ModelAction * get_last_seq_cst(ModelAction *curr) const;
135 ModelAction * get_last_unlock(ModelAction *curr) const;
136 void build_reads_from_past(ModelAction *curr);
137 ModelAction * process_rmw(ModelAction *curr);
138 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
139 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
140 bool w_modification_order(ModelAction *curr);
141 bool release_seq_head(const ModelAction *rf, rel_heads_list_t *release_heads) const;
142 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
143 void do_complete_join(ModelAction *join);
145 ModelAction *diverge;
147 ucontext_t system_context;
148 action_list_t *action_trace;
149 HashTable<int, Thread *, int> *thread_map;
151 /** Per-object list of actions. Maps an object (i.e., memory location)
152 * to a trace of all actions performed on the object. */
153 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
155 /** Per-object list of actions. Maps an object (i.e., memory location)
156 * to a trace of all actions performed on the object. */
157 HashTable<const void *, action_list_t, uintptr_t, 4> *lock_waiters_map;
159 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
160 std::vector<Promise *> *promises;
161 std::vector<struct PendingFutureValue> *futurevalues;
164 * List of acquire actions that might synchronize with one or more
165 * release sequence. Release sequences might be determined lazily as
166 * promises are fulfilled and modification orders are established. Each
167 * ModelAction in this list must be an acquire operation.
169 std::vector<ModelAction *> *pending_acq_rel_seq;
171 std::vector<ModelAction *> *thrd_last_action;
172 NodeStack *node_stack;
174 /** Private data members that should be snapshotted. They are grouped
175 * together for efficiency and maintainability. */
176 struct model_snapshot_members *priv;
179 * @brief The modification order graph
181 * A directed acyclic graph recording observations of the modification
182 * order on all the atomic objects in the system. This graph should
183 * never contain any cycles, as that represents a violation of the
184 * memory model (total ordering). This graph really consists of many
185 * disjoint (unconnected) subgraphs, each graph corresponding to a
186 * separate ordering on a distinct object.
188 * The edges in this graph represent the "ordered before" relation,
189 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
192 CycleGraph *mo_graph;
198 extern ModelChecker *model;
200 #endif /* __MODEL_H__ */