threads: don't make direct call into scheduler

[model-checker.git] / model.cc

diff --git a/model.cc b/model.cc
index 37baf9b504b44c8a1894fba92e673216007c432d..f50b0f9a60777557429c33ab7fc4b3236ef1cb6f 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -13,21 +13,26 @@ ModelChecker::ModelChecker()
        /* Initialize default scheduler */
        this->scheduler = new Scheduler();
 
+       num_executions = 0;
        this->current_action = NULL;
+       this->exploring = NULL;
+       this->nextThread = THREAD_ID_T_NONE;
 
        rootNode = new TreeNode(NULL);
        currentNode = rootNode;
+       action_trace = new action_list_t();
 }
 
 ModelChecker::~ModelChecker()
 {
+       delete action_trace;
        delete this->scheduler;
        delete rootNode;
 }
 
-void ModelChecker::assign_id(Thread *t)
+int ModelChecker::get_next_id()
 {
-       t->set_id(++used_thread_id);
+       return ++used_thread_id;
 }
 
 void ModelChecker::add_system_thread(Thread *t)
@@ -35,6 +40,102 @@ void ModelChecker::add_system_thread(Thread *t)
        this->system_thread = t;
 }
 
+Thread * ModelChecker::schedule_next_thread()
+{
+       Thread *t;
+       if (nextThread == THREAD_ID_T_NONE)
+               return NULL;
+       t = thread_map[nextThread];
+       if (t == NULL)
+               DEBUG("*** error: thread not in thread_map: id = %d\n", nextThread);
+       return t;
+}
+
+/*
+ * get_next_replay_thread() - Choose the next thread in the replay sequence
+ *
+ * If we've reached the 'diverge' point, then we pick a thread from the
+ *   backtracking set.
+ * Otherwise, we simply return the next thread in the sequence.
+ */
+thread_id_t ModelChecker::get_next_replay_thread()
+{
+       ModelAction *next;
+       thread_id_t tid;
+
+       next = exploring->get_state();
+
+       if (next == exploring->get_diverge()) {
+               TreeNode *node = next->get_node();
+
+               /* Reached divergence point; discard our current 'exploring' */
+               DEBUG("*** Discard 'Backtrack' object ***\n");
+               tid = node->getNextBacktrack();
+               delete exploring;
+               exploring = NULL;
+       } else {
+               tid = next->get_tid();
+       }
+       DEBUG("*** ModelChecker chose next thread = %d ***\n", tid);
+       return tid;
+}
+
+thread_id_t ModelChecker::advance_backtracking_state()
+{
+       /* Have we completed exploring the preselected path? */
+       if (exploring == NULL)
+               return THREAD_ID_T_NONE;
+
+       /* Else, we are trying to replay an execution */
+       exploring->advance_state();
+       if (exploring->get_state() == NULL)
+               DEBUG("*** error: reached end of backtrack trace\n");
+
+       return get_next_replay_thread();
+}
+
+bool ModelChecker::next_execution()
+{
+       num_executions++;
+       if ((exploring = model->get_next_backtrack()) == NULL)
+               return false;
+       model->reset_to_initial_state();
+       nextThread = get_next_replay_thread();
+       return true;
+}
+
+ModelAction * ModelChecker::get_last_conflict(ModelAction *act)
+{
+       void *loc = act->get_location();
+       action_type type = act->get_type();
+       thread_id_t id = act->get_tid();
+
+       switch (type) {
+               case THREAD_CREATE:
+               case THREAD_YIELD:
+               case THREAD_JOIN:
+                       return NULL;
+               case ATOMIC_READ:
+               case ATOMIC_WRITE:
+               default:
+                       break;
+       }
+       /* linear search: from most recent to oldest */
+       action_list_t::reverse_iterator rit;
+       for (rit = action_trace->rbegin(); rit != action_trace->rend(); rit++) {
+               ModelAction *prev = *rit;
+               if (prev->get_location() != loc)
+                       continue;
+               if (type == ATOMIC_READ && prev->get_type() != ATOMIC_WRITE)
+                       continue;
+               /* Conflict from the same thread is not really a conflict */
+               if (id == prev->get_tid())
+                       return NULL;
+               return prev;
+       }
+       return NULL;
+}
+
 void ModelChecker::set_backtracking(ModelAction *act)
 {
        ModelAction *prev;
@@ -58,9 +159,8 @@ void ModelChecker::set_backtracking(ModelAction *act)
        prev->print();
        act->print();
 
-       /* FIXME */
-       //Backtrack *back = new Backtrack(prev, actionList);
-       //backtrackList->Append(back);
+       Backtrack *back = new Backtrack(prev, action_trace);
+       backtrack_list.push_back(back);
 }
 
 void ModelChecker::check_current_action(void)
@@ -71,25 +171,37 @@ void ModelChecker::check_current_action(void)
                DEBUG("trying to push NULL action...\n");
                return;
        }
+       nextThread = advance_backtracking_state();
        next->set_node(currentNode);
        set_backtracking(next);
        currentNode = currentNode->exploreChild(next->get_tid());
-       this->action_trace.push_back(next);
+       this->action_trace->push_back(next);
 }
 
 void ModelChecker::print_trace(void)
 {
-       std::list<class ModelAction *>::iterator it;
+       action_list_t::iterator it;
+
+       printf("\n");
+       printf("---------------------------------------------------------------------\n");
+       printf("Number of executions: %d\n", num_executions);
+       printf("Total nodes created: %d\n\n", TreeNode::getTotalNodes());
+
+       scheduler->print();
+
+       printf("\nTrace:\n\n");
 
-       for (it = action_trace.begin(); it != action_trace.end(); it++) {
+       for (it = action_trace->begin(); it != action_trace->end(); it++) {
                DBG();
                (*it)->print();
        }
+       printf("---------------------------------------------------------------------\n");
 }
 
 int ModelChecker::add_thread(Thread *t)
 {
        thread_map[t->get_id()] = t;
+       scheduler->add_thread(t);
        return 0;
 }