7 #include "snapshot-interface.h"
10 #define INITIAL_THREAD_ID 0
14 ModelChecker::ModelChecker()
16 /* Initialize default scheduler */
17 scheduler(new Scheduler()),
18 /* First thread created will have id INITIAL_THREAD_ID */
19 next_thread_id(INITIAL_THREAD_ID),
20 used_sequence_numbers(0),
25 nextThread(THREAD_ID_T_NONE),
26 action_trace(new action_list_t()),
27 thread_map(new std::map<int, class Thread *>),
28 node_stack(new NodeStack()),
33 ModelChecker::~ModelChecker()
35 std::map<int, class Thread *>::iterator it;
36 for (it = thread_map->begin(); it != thread_map->end(); it++)
46 void ModelChecker::reset_to_initial_state()
48 DEBUG("+++ Resetting to initial state +++\n");
49 node_stack->reset_execution();
50 current_action = NULL;
51 next_thread_id = INITIAL_THREAD_ID;
52 used_sequence_numbers = 0;
54 next_backtrack = NULL;
55 snapshotObject->backTrackBeforeStep(0);
58 thread_id_t ModelChecker::get_next_id()
60 return next_thread_id++;
63 int ModelChecker::get_next_seq_num()
65 return ++used_sequence_numbers;
68 Thread * ModelChecker::schedule_next_thread()
71 if (nextThread == THREAD_ID_T_NONE)
73 t = (*thread_map)[id_to_int(nextThread)];
81 * get_next_replay_thread() - Choose the next thread in the replay sequence
83 * If we've reached the 'diverge' point, then we pick a thread from the
85 * Otherwise, we simply return the next thread in the sequence.
87 thread_id_t ModelChecker::get_next_replay_thread()
92 /* Have we completed exploring the preselected path? */
94 return THREAD_ID_T_NONE;
96 /* Else, we are trying to replay an execution */
97 next = node_stack->get_next()->get_action();
99 if (next == diverge) {
100 Node *node = next->get_node();
102 /* Reached divergence point */
103 DEBUG("*** Divergence point ***\n");
104 tid = node->get_next_backtrack();
107 tid = next->get_tid();
109 DEBUG("*** ModelChecker chose next thread = %d ***\n", tid);
113 bool ModelChecker::next_execution()
119 if ((diverge = model->get_next_backtrack()) == NULL)
123 printf("Next execution will diverge at:\n");
127 model->reset_to_initial_state();
131 ModelAction * ModelChecker::get_last_conflict(ModelAction *act)
133 action_type type = act->get_type();
145 /* linear search: from most recent to oldest */
146 action_list_t::reverse_iterator rit;
147 for (rit = action_trace->rbegin(); rit != action_trace->rend(); rit++) {
148 ModelAction *prev = *rit;
149 if (act->is_dependent(prev))
155 void ModelChecker::set_backtracking(ModelAction *act)
159 Thread *t = get_thread(act->get_tid());
161 prev = get_last_conflict(act);
165 node = prev->get_node();
167 while (!node->is_enabled(t))
170 /* Check if this has been explored already */
171 if (node->has_been_explored(t->get_id()))
174 if (!next_backtrack || *prev > *next_backtrack)
175 next_backtrack = prev;
177 /* If this is a new backtracking point, mark the tree */
178 if (!node->set_backtrack(t->get_id()))
180 DEBUG("Setting backtrack: conflict = %d, instead tid = %d\n",
181 prev->get_tid(), t->get_id());
188 ModelAction * ModelChecker::get_next_backtrack()
190 ModelAction *next = next_backtrack;
191 next_backtrack = NULL;
195 void ModelChecker::check_current_action(void)
199 ModelAction *curr = this->current_action;
200 current_action = NULL;
202 DEBUG("trying to push NULL action...\n");
206 curr = node_stack->explore_action(curr);
207 nextThread = get_next_replay_thread();
209 currnode = curr->get_node();
211 if (!currnode->backtrack_empty())
212 if (!next_backtrack || *curr > *next_backtrack)
213 next_backtrack = curr;
215 set_backtracking(curr);
216 this->action_trace->push_back(curr);
219 void ModelChecker::print_summary(void)
222 printf("Number of executions: %d\n", num_executions);
223 printf("Total nodes created: %d\n", Node::get_total_nodes());
227 print_list(action_trace);
231 void ModelChecker::print_list(action_list_t *list)
233 action_list_t::iterator it;
235 printf("---------------------------------------------------------------------\n");
238 for (it = list->begin(); it != list->end(); it++) {
241 printf("---------------------------------------------------------------------\n");
244 int ModelChecker::add_thread(Thread *t)
246 (*thread_map)[id_to_int(t->get_id())] = t;
247 scheduler->add_thread(t);
251 void ModelChecker::remove_thread(Thread *t)
253 scheduler->remove_thread(t);
256 int ModelChecker::switch_to_master(ModelAction *act)
261 old = thread_current();
262 set_current_action(act);
263 old->set_state(THREAD_READY);
264 return Thread::swap(old, get_system_context());