model: implement, use schedule_next_thread()

[model-checker.git] / model.cc

diff --git a/model.cc b/model.cc
index 88f6b339231cf6a51df50288e92313682158825a..26fd6cae0c6f33b04c3c2e3139f8bdc03f56565c 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -14,13 +14,17 @@ ModelChecker::ModelChecker()
        this->scheduler = new Scheduler();
 
        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;
 }
@@ -35,22 +39,102 @@ 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;
+}
+
+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;
+       }
+       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;
+       TreeNode *node;
+
+       prev = get_last_conflict(act);
+       if (prev == NULL)
+               return;
+
+       node = prev->get_node();
+
+       /* Check if this has been explored already */
+       if (node->hasBeenExplored(act->get_tid()))
+               return;
+       /* If this is a new backtracking point, mark the tree */
+       if (node->setBacktrack(act->get_tid()) != 0)
+               return;
+
+       printf("Setting backtrack: conflict = %d, instead tid = %d\n",
+                       prev->get_tid(), act->get_tid());
+       prev->print();
+       act->print();
+
+       Backtrack *back = new Backtrack(prev, action_trace);
+       backtrack_list.push_back(back);
+}
+
 void ModelChecker::check_current_action(void)
 {
-       if (this->current_action)
-               this->action_trace.push_back(this->current_action);
-       else
+       ModelAction *next = this->current_action;
+
+       if (!next) {
                DEBUG("trying to push NULL action...\n");
+               return;
+       }
+       next->set_node(currentNode);
+       set_backtracking(next);
+       currentNode = currentNode->exploreChild(next->get_tid());
+       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("Total nodes created: %d\n\n", TreeNode::getTotalNodes());
 
-       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)