2 * @brief Core model checker.
15 #include "hashtable.h"
16 #include "workqueue.h"
18 #include "modeltypes.h"
20 /* Forward declaration */
27 /** @brief Shorthand for a list of release sequence heads */
28 typedef std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > rel_heads_list_t;
31 * Model checker parameter structure. Holds run-time configuration options for
37 unsigned int fairwindow;
38 unsigned int enabledcount;
41 struct PendingFutureValue {
47 * Structure for holding small ModelChecker members that should be snapshotted
49 struct model_snapshot_members {
50 ModelAction *current_action;
51 unsigned int next_thread_id;
52 modelclock_t used_sequence_numbers;
54 ModelAction *next_backtrack;
57 /** @brief Records information regarding a single pending release sequence */
59 /** @brief The acquire operation */
61 /** @brief The head of the RMW chain from which 'acquire' reads; may be
62 * equal to 'release' */
63 const ModelAction *rf;
64 /** @brief The head of the potential longest release sequence chain */
65 const ModelAction *release;
66 /** @brief The write(s) that may break the release sequence */
67 std::vector<const ModelAction *> writes;
70 /** @brief The central structure for model-checking */
73 ModelChecker(struct model_params params);
76 /** @returns the context for the main model-checking system thread */
77 ucontext_t * get_system_context() { return &system_context; }
79 /** Prints an execution summary with trace information. */
81 #if SUPPORT_MOD_ORDER_DUMP
82 void dumpGraph(char *filename);
85 void add_thread(Thread *t);
86 void remove_thread(Thread *t);
87 Thread * get_thread(thread_id_t tid) const;
88 Thread * get_thread(ModelAction *act) const;
90 thread_id_t get_next_id();
91 unsigned int get_num_threads();
92 Thread * get_current_thread();
94 int switch_to_master(ModelAction *act);
95 ClockVector * get_cv(thread_id_t tid);
96 ModelAction * get_parent_action(thread_id_t tid);
97 bool next_execution();
99 bool isfeasibleotherthanRMW();
100 bool isfinalfeasible();
101 void mo_check_promises(thread_id_t tid, const ModelAction *write);
102 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
103 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
104 void finish_execution();
105 bool isfeasibleprefix();
106 void set_assert() {asserted=true;}
108 /** @brief Alert the model-checker that an incorrectly-ordered
109 * synchronization was made */
110 void set_bad_synchronization() { bad_synchronization = true; }
112 const model_params params;
113 Scheduler * get_scheduler() { return scheduler;}
117 /** The scheduler to use: tracks the running/ready Threads */
118 Scheduler *scheduler;
120 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
121 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
122 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
123 bool has_asserted() {return asserted;}
124 void reset_asserted() {asserted=false;}
126 int num_feasible_executions;
127 bool promises_expired();
128 void execute_sleep_set();
129 void wake_up_sleeping_actions(ModelAction * curr);
130 modelclock_t get_next_seq_num();
133 * Stores the ModelAction for the current thread action. Call this
134 * immediately before switching from user- to system-context to pass
136 * @param act The ModelAction created by the user-thread action
138 void set_current_action(ModelAction *act) { priv->current_action = act; }
139 Thread * check_current_action(ModelAction *curr);
140 ModelAction * initialize_curr_action(ModelAction *curr);
141 bool process_read(ModelAction *curr, bool second_part_of_rmw);
142 bool process_write(ModelAction *curr);
143 bool process_mutex(ModelAction *curr);
144 bool process_thread_action(ModelAction *curr);
145 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
146 bool check_action_enabled(ModelAction *curr);
150 void check_recency(ModelAction *curr, const ModelAction *rf);
151 ModelAction * get_last_conflict(ModelAction *act);
152 void set_backtracking(ModelAction *act);
153 Thread * get_next_thread(ModelAction *curr);
154 ModelAction * get_next_backtrack();
155 void reset_to_initial_state();
156 bool resolve_promises(ModelAction *curr);
157 void compute_promises(ModelAction *curr);
158 void compute_relseq_breakwrites(ModelAction *curr);
160 void check_curr_backtracking(ModelAction * curr);
161 void add_action_to_lists(ModelAction *act);
162 ModelAction * get_last_action(thread_id_t tid) const;
163 ModelAction * get_last_seq_cst(ModelAction *curr) const;
164 ModelAction * get_last_unlock(ModelAction *curr) const;
165 void build_reads_from_past(ModelAction *curr);
166 ModelAction * process_rmw(ModelAction *curr);
167 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
168 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
169 bool w_modification_order(ModelAction *curr);
170 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
171 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
172 void do_complete_join(ModelAction *join);
174 ModelAction *diverge;
175 ModelAction *earliest_diverge;
177 ucontext_t system_context;
178 action_list_t *action_trace;
179 HashTable<int, Thread *, int> *thread_map;
181 /** Per-object list of actions. Maps an object (i.e., memory location)
182 * to a trace of all actions performed on the object. */
183 HashTable<const void *, action_list_t, uintptr_t, 4> *obj_map;
185 /** Per-object list of actions. Maps an object (i.e., memory location)
186 * to a trace of all actions performed on the object. */
187 HashTable<const void *, action_list_t, uintptr_t, 4> *lock_waiters_map;
189 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
190 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
191 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
194 * List of pending release sequences. Release sequences might be
195 * determined lazily as promises are fulfilled and modification orders
196 * are established. Each entry in the list may only be partially
197 * filled, depending on its pending status.
199 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
201 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
202 NodeStack *node_stack;
204 /** Private data members that should be snapshotted. They are grouped
205 * together for efficiency and maintainability. */
206 struct model_snapshot_members *priv;
208 /** A special model-checker Thread; used for associating with
209 * model-checker-related ModelAcitons */
210 Thread *model_thread;
213 * @brief The modification order graph
215 * A directed acyclic graph recording observations of the modification
216 * order on all the atomic objects in the system. This graph should
217 * never contain any cycles, as that represents a violation of the
218 * memory model (total ordering). This graph really consists of many
219 * disjoint (unconnected) subgraphs, each graph corresponding to a
220 * separate ordering on a distinct object.
222 * The edges in this graph represent the "ordered before" relation,
223 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
226 CycleGraph *mo_graph;
230 /** @brief Incorrectly-ordered synchronization was made */
231 bool bad_synchronization;
234 extern ModelChecker *model;
236 #endif /* __MODEL_H__ */