2 * @brief Core model checker.
15 #include "hashtable.h"
16 #include "workqueue.h"
18 #include "modeltypes.h"
20 /* Forward declaration */
26 struct model_snapshot_members;
28 /** @brief Shorthand for a list of release sequence heads */
29 typedef std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > rel_heads_list_t;
32 * Model checker parameter structure. Holds run-time configuration options for
38 unsigned int fairwindow;
39 unsigned int enabledcount;
42 /** @brief Maximum number of future values that can be sent to the same
46 /** @brief Only generate a new future value/expiration pair if the
47 * expiration time exceeds the existing one by more than the slop
49 unsigned int expireslop;
52 struct PendingFutureValue {
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 bool is_enabled(Thread *t) const;
91 bool is_enabled(thread_id_t tid) const;
93 thread_id_t get_next_id();
94 unsigned int get_num_threads() const;
95 Thread * get_current_thread();
97 int switch_to_master(ModelAction *act);
98 ClockVector * get_cv(thread_id_t tid);
99 ModelAction * get_parent_action(thread_id_t tid);
100 bool next_execution();
102 bool isfeasibleotherthanRMW();
103 bool isfinalfeasible();
104 void check_promises_thread_disabled();
105 void mo_check_promises(thread_id_t tid, const ModelAction *write);
106 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
107 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
108 void finish_execution();
109 bool isfeasibleprefix();
110 void set_assert() {asserted=true;}
111 bool is_deadlocked() const;
112 bool is_complete_execution() const;
114 /** @brief Alert the model-checker that an incorrectly-ordered
115 * synchronization was made */
116 void set_bad_synchronization() { bad_synchronization = true; }
118 const model_params params;
119 Node * get_curr_node();
123 /** The scheduler to use: tracks the running/ready Threads */
124 Scheduler *scheduler;
126 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
127 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
128 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
129 bool has_asserted() {return asserted;}
130 void reset_asserted() {asserted=false;}
132 int num_feasible_executions;
133 bool promises_expired();
134 void execute_sleep_set();
135 void wake_up_sleeping_actions(ModelAction * curr);
136 modelclock_t get_next_seq_num();
138 void set_current_action(ModelAction *act);
139 Thread * check_current_action(ModelAction *curr);
140 bool 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);
173 ModelAction *diverge;
174 ModelAction *earliest_diverge;
176 ucontext_t system_context;
177 action_list_t *action_trace;
178 HashTable<int, Thread *, int> *thread_map;
180 /** Per-object list of actions. Maps an object (i.e., memory location)
181 * to a trace of all actions performed on the object. */
182 HashTable<const void *, action_list_t *, uintptr_t, 4> *obj_map;
184 /** Per-object list of actions. Maps an object (i.e., memory location)
185 * to a trace of all actions performed on the object. */
186 HashTable<const void *, action_list_t *, uintptr_t, 4> *lock_waiters_map;
188 /** Per-object list of actions. Maps an object (i.e., memory location)
189 * to a trace of all actions performed on the object. */
190 HashTable<const void *, action_list_t *, uintptr_t, 4> *condvar_waiters_map;
192 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > *obj_thrd_map;
193 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
194 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
197 * List of pending release sequences. Release sequences might be
198 * determined lazily as promises are fulfilled and modification orders
199 * are established. Each entry in the list may only be partially
200 * filled, depending on its pending status.
202 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
204 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
205 NodeStack *node_stack;
207 /** Private data members that should be snapshotted. They are grouped
208 * together for efficiency and maintainability. */
209 struct model_snapshot_members *priv;
211 /** A special model-checker Thread; used for associating with
212 * model-checker-related ModelAcitons */
213 Thread *model_thread;
216 * @brief The modification order graph
218 * A directed acyclic graph recording observations of the modification
219 * order on all the atomic objects in the system. This graph should
220 * never contain any cycles, as that represents a violation of the
221 * memory model (total ordering). This graph really consists of many
222 * disjoint (unconnected) subgraphs, each graph corresponding to a
223 * separate ordering on a distinct object.
225 * The edges in this graph represent the "ordered before" relation,
226 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
229 CycleGraph *mo_graph;
233 /** @brief Incorrectly-ordered synchronization was made */
234 bool bad_synchronization;
237 extern ModelChecker *model;
239 #endif /* __MODEL_H__ */