X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=bf956804479f3f1e82fe8f04fb273d50ce7c9cbb;hb=6357baf85edec072a52c7ea18e9fdb087765f9cb;hp=e496abd012a537b13019c292741a8dda6bc71935;hpb=d559cca6ce8264cee284dda4e0962b3bb564c955;p=model-checker.git

diff --git a/model.cc b/model.cc
index e496abd..bf95680 100644
--- a/model.cc
+++ b/model.cc
@@ -14,6 +14,8 @@ 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;
@@ -37,6 +39,60 @@ 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();
+}
+
 ModelAction *ModelChecker::get_last_conflict(ModelAction *act)
 {
 	void *loc = act->get_location();
@@ -53,6 +109,7 @@ 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;
@@ -91,9 +148,8 @@ 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)
@@ -104,6 +160,7 @@ 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());