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;
55 /** @see ModelChecker::lazy_sync_size */
56 unsigned int lazy_sync_size;
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. */
71 void add_thread(Thread *t);
72 void remove_thread(Thread *t);
73 Thread * get_thread(thread_id_t tid) { return thread_map->get(id_to_int(tid)); }
74 Thread * get_thread(ModelAction *act) { return get_thread(act->get_tid()); }
76 thread_id_t get_next_id();
77 int get_num_threads();
78 modelclock_t get_next_seq_num();
80 /** @return The currently executing Thread. */
81 Thread * get_current_thread() { return scheduler->get_current_thread(); }
83 int switch_to_master(ModelAction *act);
84 ClockVector * get_cv(thread_id_t tid);
85 ModelAction * get_parent_action(thread_id_t tid);
86 bool next_execution();
88 bool isfeasibleotherthanRMW();
89 bool isfinalfeasible();
90 void check_promises(ClockVector *old_cv, ClockVector * merge_cv);
91 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
92 void finish_execution();
93 bool isfeasibleprefix();
94 void set_assert() {asserted=true;}
98 /** The scheduler to use: tracks the running/ready Threads */
101 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
102 bool has_asserted() {return asserted;}
103 void reset_asserted() {asserted=false;}
105 int num_feasible_executions;
106 bool promises_expired();
107 const model_params params;
110 * Stores the ModelAction for the current thread action. Call this
111 * immediately before switching from user- to system-context to pass
113 * @param act The ModelAction created by the user-thread action
115 void set_current_action(ModelAction *act) { priv->current_action = act; }
116 Thread * check_current_action(ModelAction *curr);
117 ModelAction * initialize_curr_action(ModelAction *curr);
118 bool process_read(ModelAction *curr, bool second_part_of_rmw);
119 bool process_write(ModelAction *curr);
123 void check_recency(ModelAction *curr);
124 ModelAction * get_last_conflict(ModelAction *act);
125 void set_backtracking(ModelAction *act);
126 Thread * get_next_thread(ModelAction *curr);
127 ModelAction * get_next_backtrack();
128 void reset_to_initial_state();
129 bool resolve_promises(ModelAction *curr);
130 void compute_promises(ModelAction *curr);
132 void check_curr_backtracking(ModelAction * curr);
133 void add_action_to_lists(ModelAction *act);
134 ModelAction * get_last_action(thread_id_t tid);
135 ModelAction * get_last_seq_cst(ModelAction *curr);
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 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
156 std::vector<Promise *> *promises;
157 std::vector<struct PendingFutureValue> *futurevalues;
160 * Collection of lists of objects that might synchronize with one or
161 * more release sequence. Release sequences might be determined lazily
162 * as promises are fulfilled and modification orders are established.
163 * This structure maps its lists by object location. Each ModelAction
164 * in the lists should be an acquire operation.
166 HashTable<void *, action_list_t, uintptr_t, 4> *lazy_sync_with_release;
169 * Represents the total size of the
170 * ModelChecker::lazy_sync_with_release lists. This count should be
171 * snapshotted, so it is actually a pointer to a location within
174 unsigned int *lazy_sync_size;
176 std::vector<ModelAction *> *thrd_last_action;
177 NodeStack *node_stack;
179 /** Private data members that should be snapshotted. They are grouped
180 * together for efficiency and maintainability. */
181 struct model_snapshot_members *priv;
184 * @brief The modification order graph
186 * A directed acyclic graph recording observations of the modification
187 * order on all the atomic objects in the system. This graph should
188 * never contain any cycles, as that represents a violation of the
189 * memory model (total ordering). This graph really consists of many
190 * disjoint (unconnected) subgraphs, each graph corresponding to a
191 * separate ordering on a distinct object.
193 * The edges in this graph represent the "ordered before" relation,
194 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
197 CycleGraph *mo_graph;
203 extern ModelChecker *model;
205 #endif /* __MODEL_H__ */