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;
113 /** @brief Alert the model-checker that an incorrectly-ordered
114 * synchronization was made */
115 void set_bad_synchronization() { bad_synchronization = true; }
117 const model_params params;
118 Node * get_curr_node();
122 /** The scheduler to use: tracks the running/ready Threads */
123 Scheduler *scheduler;
125 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
126 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
127 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
128 bool has_asserted() {return asserted;}
129 void reset_asserted() {asserted=false;}
131 int num_feasible_executions;
132 bool promises_expired();
133 void execute_sleep_set();
134 void wake_up_sleeping_actions(ModelAction * curr);
135 modelclock_t get_next_seq_num();
137 void set_current_action(ModelAction *act);
138 Thread * check_current_action(ModelAction *curr);
139 bool initialize_curr_action(ModelAction **curr);
140 bool process_read(ModelAction *curr, bool second_part_of_rmw);
141 bool process_write(ModelAction *curr);
142 bool process_mutex(ModelAction *curr);
143 bool process_thread_action(ModelAction *curr);
144 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
145 bool check_action_enabled(ModelAction *curr);
149 void check_recency(ModelAction *curr, const ModelAction *rf);
150 ModelAction * get_last_conflict(ModelAction *act);
151 void set_backtracking(ModelAction *act);
152 Thread * get_next_thread(ModelAction *curr);
153 ModelAction * get_next_backtrack();
154 void reset_to_initial_state();
155 bool resolve_promises(ModelAction *curr);
156 void compute_promises(ModelAction *curr);
157 void compute_relseq_breakwrites(ModelAction *curr);
159 void check_curr_backtracking(ModelAction * curr);
160 void add_action_to_lists(ModelAction *act);
161 ModelAction * get_last_action(thread_id_t tid) const;
162 ModelAction * get_last_seq_cst(ModelAction *curr) const;
163 ModelAction * get_last_unlock(ModelAction *curr) const;
164 void build_reads_from_past(ModelAction *curr);
165 ModelAction * process_rmw(ModelAction *curr);
166 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
167 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
168 bool w_modification_order(ModelAction *curr);
169 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
170 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
172 ModelAction *diverge;
173 ModelAction *earliest_diverge;
175 ucontext_t system_context;
176 action_list_t *action_trace;
177 HashTable<int, Thread *, int> *thread_map;
179 /** Per-object list of actions. Maps an object (i.e., memory location)
180 * to a trace of all actions performed on the object. */
181 HashTable<const void *, action_list_t *, uintptr_t, 4> *obj_map;
183 /** Per-object list of actions. Maps an object (i.e., memory location)
184 * to a trace of all actions performed on the object. */
185 HashTable<const void *, action_list_t *, uintptr_t, 4> *lock_waiters_map;
187 /** Per-object list of actions. Maps an object (i.e., memory location)
188 * to a trace of all actions performed on the object. */
189 HashTable<const void *, action_list_t *, uintptr_t, 4> *condvar_waiters_map;
191 HashTable<void *, std::vector<action_list_t> *, uintptr_t, 4 > *obj_thrd_map;
192 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
193 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
196 * List of pending release sequences. Release sequences might be
197 * determined lazily as promises are fulfilled and modification orders
198 * are established. Each entry in the list may only be partially
199 * filled, depending on its pending status.
201 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
203 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
204 NodeStack *node_stack;
206 /** Private data members that should be snapshotted. They are grouped
207 * together for efficiency and maintainability. */
208 struct model_snapshot_members *priv;
210 /** A special model-checker Thread; used for associating with
211 * model-checker-related ModelAcitons */
212 Thread *model_thread;
215 * @brief The modification order graph
217 * A directed acyclic graph recording observations of the modification
218 * order on all the atomic objects in the system. This graph should
219 * never contain any cycles, as that represents a violation of the
220 * memory model (total ordering). This graph really consists of many
221 * disjoint (unconnected) subgraphs, each graph corresponding to a
222 * separate ordering on a distinct object.
224 * The edges in this graph represent the "ordered before" relation,
225 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
228 CycleGraph *mo_graph;
232 /** @brief Incorrectly-ordered synchronization was made */
233 bool bad_synchronization;
236 extern ModelChecker *model;
238 #endif /* __MODEL_H__ */