+/* 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;
+}
+