+ return func_node_list;
+}
+
+SnapVector<FuncNode *> * ModelHistory::getWrFuncNodes(void * location)
+{
+ SnapVector<FuncNode *> * func_node_list = loc_wr_func_nodes_map->get(location);
+ if (func_node_list == NULL) {
+ func_node_list = new SnapVector<FuncNode *>();
+ loc_wr_func_nodes_map->put(location, func_node_list);
+ }
+
+ return func_node_list;
+}
+
+/* When a thread is paused by Fuzzer, keep track of the condition it is waiting for */
+void ModelHistory::add_waiting_write(ConcretePredicate * concrete)
+{
+ void * location = concrete->get_location();
+ SnapVector<ConcretePredicate *> * waiting_conditions = loc_waiting_writes_map->get(location);
+ if (waiting_conditions == NULL) {
+ waiting_conditions = new SnapVector<ConcretePredicate *>();
+ loc_waiting_writes_map->put(location, waiting_conditions);
+ }
+
+ /* waiting_conditions should not have duplications */
+ waiting_conditions->push_back(concrete);
+
+ int thread_id = id_to_int(concrete->get_tid());
+ if (thrd_waiting_write->size() <= (uint) thread_id) {
+ thrd_waiting_write->resize(thread_id + 1);
+ }
+
+ (*thrd_waiting_write)[thread_id] = concrete;
+}
+
+void ModelHistory::remove_waiting_write(thread_id_t tid)
+{
+ ConcretePredicate * concrete = (*thrd_waiting_write)[ id_to_int(tid) ];
+ void * location = concrete->get_location();
+ SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
+
+ /* Linear search should be fine because presumably not many ConcretePredicates
+ * are at the same memory location */
+ for (uint i = 0;i < concrete_preds->size();i++) {
+ ConcretePredicate * current = (*concrete_preds)[i];
+ if (concrete == current) {
+ (*concrete_preds)[i] = concrete_preds->back();
+ concrete_preds->pop_back();
+ break;
+ }
+ }
+
+ int thread_id = id_to_int( concrete->get_tid() );
+ (*thrd_waiting_write)[thread_id] = NULL;
+ delete concrete;
+}
+
+/* Check if any other thread is waiting for this write action. If so, "notify" them */
+void ModelHistory::check_waiting_write(ModelAction * write_act)
+{
+ void * location = write_act->get_location();
+ uint64_t value = write_act->get_write_value();
+ SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
+ if (concrete_preds == NULL)
+ return;
+
+ uint index = 0;
+ while (index < concrete_preds->size()) {
+ ConcretePredicate * concrete_pred = (*concrete_preds)[index];
+ SnapVector<struct concrete_pred_expr> * concrete_exprs = concrete_pred->getExpressions();
+ bool satisfy_predicate = true;
+ /* Check if the written value satisfies every predicate expression */
+ for (uint i = 0;i < concrete_exprs->size();i++) {
+ struct concrete_pred_expr concrete = (*concrete_exprs)[i];
+ bool equality = false;
+ switch (concrete.token) {
+ case EQUALITY:
+ equality = (value == concrete.value);
+ break;
+ case NULLITY:
+ equality = ((void*)value == NULL);
+ break;
+ default:
+ model_print("unknown predicate token");
+ break;
+ }
+
+ if (equality != concrete.equality) {
+ satisfy_predicate = false;
+ break;
+ }
+ }
+
+ if (satisfy_predicate) {
+ /* Wake up threads */
+ thread_id_t tid = concrete_pred->get_tid();
+ Thread * thread = model->get_thread(tid);
+
+ //model_print("** thread %d is woken up\n", thread->get_id());
+ ((NewFuzzer *)model->get_execution()->getFuzzer())->notify_paused_thread(thread);
+ }
+
+ index++;
+ }
+}
+
+WaitObj * ModelHistory::getWaitObj(thread_id_t tid)
+{
+ int thread_id = id_to_int(tid);
+ int old_size = thrd_wait_obj->size();
+ if (old_size <= thread_id) {
+ thrd_wait_obj->resize(thread_id + 1);
+ for (int i = old_size;i < thread_id + 1;i++) {
+ (*thrd_wait_obj)[i] = new WaitObj( int_to_id(i) );
+ }
+ }
+
+ return (*thrd_wait_obj)[thread_id];
+}
+
+void ModelHistory::add_waiting_thread(thread_id_t self_id,
+ thread_id_t waiting_for_id, FuncNode * target_node, int dist)
+{
+ WaitObj * self_wait_obj = getWaitObj(self_id);
+ self_wait_obj->add_waiting_for(waiting_for_id, target_node, dist);
+
+ /* Update waited-by relation */
+ WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
+ other_wait_obj->add_waited_by(self_id);
+}
+
+/* Thread tid is woken up (or notified), so it is not waiting for others anymore */
+void ModelHistory::remove_waiting_thread(thread_id_t tid)
+{
+ WaitObj * self_wait_obj = getWaitObj(tid);
+ thrd_id_set_t * waiting_for = self_wait_obj->getWaitingFor();
+
+ /* Remove tid from waited_by's */
+ thrd_id_set_iter * iter = waiting_for->iterator();
+ while (iter->hasNext()) {
+ thread_id_t other_id = iter->next();
+ WaitObj * other_wait_obj = getWaitObj(other_id);
+ other_wait_obj->remove_waited_by(tid);
+ }
+
+ self_wait_obj->clear_waiting_for();
+ delete iter;
+}
+
+void ModelHistory::stop_waiting_for_node(thread_id_t self_id,
+ thread_id_t waiting_for_id, FuncNode * target_node)
+{
+ WaitObj * self_wait_obj = getWaitObj(self_id);
+ bool thread_removed = self_wait_obj->remove_waiting_for_node(waiting_for_id, target_node);
+
+ // model_print("\t%d gives up %d on node %d\n", self_id, waiting_for_id, target_node->get_func_id());
+
+ /* If thread self_id is not waiting for waiting_for_id anymore */
+ if (thread_removed) {
+ WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
+ other_wait_obj->remove_waited_by(self_id);
+
+ thrd_id_set_t * self_waiting_for = self_wait_obj->getWaitingFor();
+ if ( self_waiting_for->isEmpty() ) {
+ // model_print("\tthread %d waits for nobody, wake up\n", self_id);
+ ModelExecution * execution = model->get_execution();
+ Thread * thread = execution->get_thread(self_id);
+ ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
+ }
+ }
+}
+
+bool ModelHistory::skip_action(ModelAction * act)
+{
+ bool second_part_of_rmw = act->is_rmwc() || act->is_rmw();
+ modelclock_t curr_seq_number = act->get_seq_number();
+
+ /* Skip actions that are second part of a read modify write */
+ if (second_part_of_rmw)
+ return true;
+
+ /* Skip actions with the same sequence number */
+ if (last_action != NULL) {
+ if (last_action->get_seq_number() == curr_seq_number)
+ return true;
+ }
+
+ /* Skip actions that are paused by fuzzer (sequence number is 0) */
+ if (curr_seq_number == 0)
+ return true;
+
+ return false;
+}
+
+/* Monitor thread tid and decide whether other threads (that are waiting for tid)
+ * should keep waiting for this thread or not. Shall only be called when a thread
+ * enters a function.
+ *
+ * Heuristics: If the distance from the current FuncNode to some target node
+ * ever increases, stop waiting for this thread on this target node.
+ */
+void ModelHistory::monitor_waiting_thread(uint32_t func_id, thread_id_t tid)
+{
+ WaitObj * wait_obj = getWaitObj(tid);
+ thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
+ FuncNode * curr_node = func_nodes[func_id];
+
+ /* For each thread waiting for tid */
+ thrd_id_set_iter * tid_iter = waited_by->iterator();
+ while (tid_iter->hasNext()) {
+ thread_id_t waited_by_id = tid_iter->next();
+ WaitObj * other_wait_obj = getWaitObj(waited_by_id);
+
+ node_set_t * target_nodes = other_wait_obj->getTargetNodes(tid);
+ node_set_iter * node_iter = target_nodes->iterator();
+ while (node_iter->hasNext()) {
+ FuncNode * target = node_iter->next();
+ int old_dist = other_wait_obj->lookup_dist(tid, target);
+ int new_dist = curr_node->compute_distance(target, old_dist);
+
+ if (new_dist == -1) {
+ stop_waiting_for_node(waited_by_id, tid, target);
+ }
+ }
+
+ delete node_iter;
+ }
+
+ delete tid_iter;
+}
+
+void ModelHistory::monitor_waiting_thread_counter(thread_id_t tid)
+{
+ WaitObj * wait_obj = getWaitObj(tid);
+ thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
+
+ // Thread tid has taken an action, update the counter for threads waiting for tid
+ thrd_id_set_iter * tid_iter = waited_by->iterator();
+ while (tid_iter->hasNext()) {
+ thread_id_t waited_by_id = tid_iter->next();
+ WaitObj * other_wait_obj = getWaitObj(waited_by_id);
+
+ bool expire = other_wait_obj->incr_counter(tid);
+ if (expire) {
+// model_print("thread %d stops waiting for thread %d\n", waited_by_id, tid);
+ wait_obj->remove_waited_by(waited_by_id);
+ other_wait_obj->remove_waiting_for(tid);
+
+ thrd_id_set_t * other_waiting_for = other_wait_obj->getWaitingFor();
+ if ( other_waiting_for->isEmpty() ) {
+ // model_print("\tthread %d waits for nobody, wake up\n", self_id);
+ ModelExecution * execution = model->get_execution();
+ Thread * thread = execution->get_thread(waited_by_id);
+ ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
+ }
+ }
+ }
+
+ delete tid_iter;