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 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 bool process_read(ModelAction *curr, bool second_part_of_rmw);
115 bool process_write(ModelAction *curr);
119 void check_recency(ModelAction *curr, bool already_added);
120 ModelAction * get_last_conflict(ModelAction *act);
121 void set_backtracking(ModelAction *act);
122 Thread * get_next_thread(ModelAction *curr);
123 ModelAction * get_next_backtrack();
124 void reset_to_initial_state();
125 bool resolve_promises(ModelAction *curr);
126 void compute_promises(ModelAction *curr);
128 void check_curr_backtracking(ModelAction * curr);
129 void add_action_to_lists(ModelAction *act);
130 ModelAction * get_last_action(thread_id_t tid);
131 ModelAction * get_last_seq_cst(const void *location);
132 void build_reads_from_past(ModelAction *curr);
133 ModelAction * process_rmw(ModelAction *curr);
134 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
135 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
136 bool w_modification_order(ModelAction *curr);
137 bool release_seq_head(const ModelAction *rf,
138 std::vector< const ModelAction *, MyAlloc<const ModelAction *> > *release_heads) const;
139 bool resolve_release_sequences(void *location);
141 ModelAction *diverge;
143 ucontext_t system_context;
144 action_list_t *action_trace;
145 HashTable<int, Thread *, int> *thread_map;
147 /** Per-object list of actions. Maps an object (i.e., memory location)
148 * to a trace of all actions performed on the object. */
149 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
151 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
152 std::vector<Promise *> *promises;
153 std::vector<struct PendingFutureValue> *futurevalues;
156 * Collection of lists of objects that might synchronize with one or
157 * more release sequence. Release sequences might be determined lazily
158 * as promises are fulfilled and modification orders are established.
159 * This structure maps its lists by object location. Each ModelAction
160 * in the lists should be an acquire operation.
162 HashTable<void *, std::list<ModelAction *>, uintptr_t, 4> *lazy_sync_with_release;
165 * Represents the total size of the
166 * ModelChecker::lazy_sync_with_release lists. This count should be
167 * snapshotted, so it is actually a pointer to a location within
170 unsigned int *lazy_sync_size;
172 std::vector<ModelAction *> *thrd_last_action;
173 NodeStack *node_stack;
175 /** Private data members that should be snapshotted. They are grouped
176 * together for efficiency and maintainability. */
177 struct model_snapshot_members *priv;
180 * @brief The modification order graph
182 * A directed acyclic graph recording observations of the modification
183 * order on all the atomic objects in the system. This graph should
184 * never contain any cycles, as that represents a violation of the
185 * memory model (total ordering). This graph really consists of many
186 * disjoint (unconnected) subgraphs, each graph corresponding to a
187 * separate ordering on a distinct object.
189 * The edges in this graph represent the "ordered before" relation,
190 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
193 CycleGraph *mo_graph;
199 extern ModelChecker *model;
201 #endif /* __MODEL_H__ */