2 * @brief Core model checker.
15 #include "libthreads.h"
18 #include "clockvector.h"
19 #include "hashtable.h"
20 #include "workqueue.h"
22 /* Forward declaration */
28 * Model checker parameter structure. Holds run-time configuration options for
36 struct PendingFutureValue {
38 modelclock_t expiration;
43 * Structure for holding small ModelChecker members that should be snapshotted
45 struct model_snapshot_members {
46 ModelAction *current_action;
48 modelclock_t used_sequence_numbers;
50 ModelAction *next_backtrack;
52 /** @see ModelChecker::lazy_sync_size */
53 unsigned int lazy_sync_size;
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,
89 std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads);
90 void finish_execution();
91 bool isfeasibleprefix();
92 void set_assert() {asserted=true;}
96 /** The scheduler to use: tracks the running/ready Threads */
99 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
100 bool has_asserted() {return asserted;}
101 void reset_asserted() {asserted=false;}
103 int num_feasible_executions;
104 bool promises_expired();
105 const model_params params;
108 * Stores the ModelAction for the current thread action. Call this
109 * immediately before switching from user- to system-context to pass
111 * @param act The ModelAction created by the user-thread action
113 void set_current_action(ModelAction *act) { priv->current_action = act; }
114 Thread * check_current_action(ModelAction *curr);
115 bool process_read(ModelAction *curr, bool second_part_of_rmw);
116 bool process_write(ModelAction *curr);
120 void check_recency(ModelAction *curr);
121 ModelAction * get_last_conflict(ModelAction *act);
122 void set_backtracking(ModelAction *act);
123 Thread * get_next_thread(ModelAction *curr);
124 ModelAction * get_next_backtrack();
125 void reset_to_initial_state();
126 bool resolve_promises(ModelAction *curr);
127 void compute_promises(ModelAction *curr);
129 void check_curr_backtracking(ModelAction * curr);
130 void add_action_to_lists(ModelAction *act);
131 ModelAction * get_last_action(thread_id_t tid);
132 ModelAction * get_last_seq_cst(ModelAction *curr);
133 void build_reads_from_past(ModelAction *curr);
134 ModelAction * process_rmw(ModelAction *curr);
135 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
136 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
137 bool w_modification_order(ModelAction *curr);
138 bool release_seq_head(const ModelAction *rf,
139 std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads) const;
140 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
142 ModelAction *diverge;
144 ucontext_t system_context;
145 action_list_t *action_trace;
146 HashTable<int, Thread *, int> *thread_map;
148 /** Per-object list of actions. Maps an object (i.e., memory location)
149 * to a trace of all actions performed on the object. */
150 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
152 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
153 std::vector<Promise *> *promises;
154 std::vector<struct PendingFutureValue> *futurevalues;
157 * Collection of lists of objects that might synchronize with one or
158 * more release sequence. Release sequences might be determined lazily
159 * as promises are fulfilled and modification orders are established.
160 * This structure maps its lists by object location. Each ModelAction
161 * in the lists should be an acquire operation.
163 HashTable<void *, std::list<ModelAction *>, uintptr_t, 4> *lazy_sync_with_release;
166 * Represents the total size of the
167 * ModelChecker::lazy_sync_with_release lists. This count should be
168 * snapshotted, so it is actually a pointer to a location within
171 unsigned int *lazy_sync_size;
173 std::vector<ModelAction *> *thrd_last_action;
174 NodeStack *node_stack;
176 /** Private data members that should be snapshotted. They are grouped
177 * together for efficiency and maintainability. */
178 struct model_snapshot_members *priv;
181 * @brief The modification order graph
183 * A directed acyclic graph recording observations of the modification
184 * order on all the atomic objects in the system. This graph should
185 * never contain any cycles, as that represents a violation of the
186 * memory model (total ordering). This graph really consists of many
187 * disjoint (unconnected) subgraphs, each graph corresponding to a
188 * separate ordering on a distinct object.
190 * The edges in this graph represent the "ordered before" relation,
191 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
194 CycleGraph *mo_graph;
200 extern ModelChecker *model;
202 #endif /* __MODEL_H__ */