threads: don't make direct call into scheduler

[model-checker.git] / model.cc

diff --git a/model.cc b/model.cc
index 17ff0f96708d2792a2aae2e4910d8ed27baa3d87..f50b0f9a60777557429c33ab7fc4b3236ef1cb6f 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -13,7 +13,10 @@ 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;
@@ -27,9 +30,9 @@ ModelChecker::~ModelChecker()
        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)
@@ -37,7 +40,71 @@ void ModelChecker::add_system_thread(Thread *t)
        this->system_thread = t;
 }
 
-ModelAction *ModelChecker::get_last_conflict(ModelAction *act)
+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();
@@ -53,6 +120,7 @@ ModelAction *ModelChecker::get_last_conflict(ModelAction *act)
                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;
@@ -103,6 +171,7 @@ 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());
@@ -115,8 +184,13 @@ void ModelChecker::print_trace(void)
 
        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++) {
                DBG();
                (*it)->print();
@@ -127,6 +201,7 @@ void ModelChecker::print_trace(void)
 int ModelChecker::add_thread(Thread *t)
 {
        thread_map[t->get_id()] = t;
+       scheduler->add_thread(t);
        return 0;
 }