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 /** @brief Maximum number of future values that can be sent to the same
46 struct PendingFutureValue {
52 * Structure for holding small ModelChecker members that should be snapshotted
54 struct model_snapshot_members {
55 ModelAction *current_action;
56 unsigned int next_thread_id;
57 modelclock_t used_sequence_numbers;
59 ModelAction *next_backtrack;
62 /** @brief Records information regarding a single pending release sequence */
64 /** @brief The acquire operation */
66 /** @brief The head of the RMW chain from which 'acquire' reads; may be
67 * equal to 'release' */
68 const ModelAction *rf;
69 /** @brief The head of the potential longest release sequence chain */
70 const ModelAction *release;
71 /** @brief The write(s) that may break the release sequence */
72 std::vector<const ModelAction *> writes;
75 /** @brief The central structure for model-checking */
78 ModelChecker(struct model_params params);
81 /** @returns the context for the main model-checking system thread */
82 ucontext_t * get_system_context() { return &system_context; }
84 /** Prints an execution summary with trace information. */
86 #if SUPPORT_MOD_ORDER_DUMP
87 void dumpGraph(char *filename);
90 void add_thread(Thread *t);
91 void remove_thread(Thread *t);
92 Thread * get_thread(thread_id_t tid) const;
93 Thread * get_thread(ModelAction *act) const;
95 thread_id_t get_next_id();
96 unsigned int get_num_threads();
97 Thread * get_current_thread();
99 int switch_to_master(ModelAction *act);
100 ClockVector * get_cv(thread_id_t tid);
101 ModelAction * get_parent_action(thread_id_t tid);
102 bool next_execution();
104 bool isfeasibleotherthanRMW();
105 bool isfinalfeasible();
106 void check_promises_thread_disabled();
107 void mo_check_promises(thread_id_t tid, const ModelAction *write);
108 void check_promises(thread_id_t tid, ClockVector *old_cv, ClockVector * merge_cv);
109 void get_release_seq_heads(ModelAction *act, rel_heads_list_t *release_heads);
110 void finish_execution();
111 bool isfeasibleprefix();
112 void set_assert() {asserted=true;}
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 Scheduler * get_scheduler() { return scheduler;}
120 Node * get_curr_node();
124 /** The scheduler to use: tracks the running/ready Threads */
125 Scheduler *scheduler;
127 bool sleep_can_read_from(ModelAction * curr, const ModelAction *write);
128 bool thin_air_constraint_may_allow(const ModelAction * writer, const ModelAction *reader);
129 bool mo_may_allow(const ModelAction * writer, const ModelAction *reader);
130 bool has_asserted() {return asserted;}
131 void reset_asserted() {asserted=false;}
133 int num_feasible_executions;
134 bool promises_expired();
135 void execute_sleep_set();
136 void wake_up_sleeping_actions(ModelAction * curr);
137 modelclock_t get_next_seq_num();
140 * Stores the ModelAction for the current thread action. Call this
141 * immediately before switching from user- to system-context to pass
143 * @param act The ModelAction created by the user-thread action
145 void set_current_action(ModelAction *act) { priv->current_action = act; }
146 Thread * check_current_action(ModelAction *curr);
147 bool initialize_curr_action(ModelAction **curr);
148 bool process_read(ModelAction *curr, bool second_part_of_rmw);
149 bool process_write(ModelAction *curr);
150 bool process_mutex(ModelAction *curr);
151 bool process_thread_action(ModelAction *curr);
152 void process_relseq_fixup(ModelAction *curr, work_queue_t *work_queue);
153 bool check_action_enabled(ModelAction *curr);
157 void check_recency(ModelAction *curr, const ModelAction *rf);
158 ModelAction * get_last_conflict(ModelAction *act);
159 void set_backtracking(ModelAction *act);
160 Thread * get_next_thread(ModelAction *curr);
161 ModelAction * get_next_backtrack();
162 void reset_to_initial_state();
163 bool resolve_promises(ModelAction *curr);
164 void compute_promises(ModelAction *curr);
165 void compute_relseq_breakwrites(ModelAction *curr);
167 void check_curr_backtracking(ModelAction * curr);
168 void add_action_to_lists(ModelAction *act);
169 ModelAction * get_last_action(thread_id_t tid) const;
170 ModelAction * get_last_seq_cst(ModelAction *curr) const;
171 ModelAction * get_last_unlock(ModelAction *curr) const;
172 void build_reads_from_past(ModelAction *curr);
173 ModelAction * process_rmw(ModelAction *curr);
174 void post_r_modification_order(ModelAction *curr, const ModelAction *rf);
175 bool r_modification_order(ModelAction *curr, const ModelAction *rf);
176 bool w_modification_order(ModelAction *curr);
177 bool release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads, struct release_seq *pending) const;
178 bool resolve_release_sequences(void *location, work_queue_t *work_queue);
180 ModelAction *diverge;
181 ModelAction *earliest_diverge;
183 ucontext_t system_context;
184 action_list_t *action_trace;
185 HashTable<int, Thread *, int> *thread_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> *obj_map;
191 /** Per-object list of actions. Maps an object (i.e., memory location)
192 * to a trace of all actions performed on the object. */
193 HashTable<const void *, action_list_t, uintptr_t, 4> *lock_waiters_map;
195 /** Per-object list of actions. Maps an object (i.e., memory location)
196 * to a trace of all actions performed on the object. */
197 HashTable<const void *, action_list_t, uintptr_t, 4> *condvar_waiters_map;
199 HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 > *obj_thrd_map;
200 std::vector< Promise *, SnapshotAlloc<Promise *> > *promises;
201 std::vector< struct PendingFutureValue, SnapshotAlloc<struct PendingFutureValue> > *futurevalues;
204 * List of pending release sequences. Release sequences might be
205 * determined lazily as promises are fulfilled and modification orders
206 * are established. Each entry in the list may only be partially
207 * filled, depending on its pending status.
209 std::vector< struct release_seq *, SnapshotAlloc<struct release_seq *> > *pending_rel_seqs;
211 std::vector< ModelAction *, SnapshotAlloc<ModelAction *> > *thrd_last_action;
212 NodeStack *node_stack;
214 /** Private data members that should be snapshotted. They are grouped
215 * together for efficiency and maintainability. */
216 struct model_snapshot_members *priv;
218 /** A special model-checker Thread; used for associating with
219 * model-checker-related ModelAcitons */
220 Thread *model_thread;
223 * @brief The modification order graph
225 * A directed acyclic graph recording observations of the modification
226 * order on all the atomic objects in the system. This graph should
227 * never contain any cycles, as that represents a violation of the
228 * memory model (total ordering). This graph really consists of many
229 * disjoint (unconnected) subgraphs, each graph corresponding to a
230 * separate ordering on a distinct object.
232 * The edges in this graph represent the "ordered before" relation,
233 * such that <tt>a --> b</tt> means <tt>a</tt> was ordered before
236 CycleGraph *mo_graph;
240 /** @brief Incorrectly-ordered synchronization was made */
241 bool bad_synchronization;
244 extern ModelChecker *model;
246 #endif /* __MODEL_H__ */