X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=f67b552dcd74ce3db332c2b157cc2515d600072f;hb=11270ed797bd19f432589cdc7b01688ef924dd34;hp=134e457eb44468e02c4d9879e89e1c25a1679c2a;hpb=7f9eb951a3ee0443169dd21ddc914df4a04c9aab;p=model-checker.git

diff --git a/model.cc b/model.cc
index 134e457..f67b552 100644
--- a/model.cc
+++ b/model.cc
@@ -235,7 +235,7 @@ void ModelChecker::wake_up_sleeping_actions(ModelAction * curr) {
 		Thread *thr=get_thread(tid);
 		if ( scheduler->get_enabled(thr) == THREAD_SLEEP_SET ) {
 			ModelAction *pending_act=thr->get_pending();
-			if (pending_act->could_synchronize_with(curr)) {
+			if ((!curr->is_rmwr())&&pending_act->could_synchronize_with(curr)) {
 				//Remove this thread from sleep set
 				scheduler->remove_sleep(thr);
 			}
@@ -383,8 +383,12 @@ void ModelChecker::set_backtracking(ModelAction *act)
 	for(int i = low_tid; i < high_tid; i++) {
 		thread_id_t tid = int_to_id(i);
 
+		/* Make sure this thread can be enabled here. */
+		if (i >= node->get_num_threads())
+			break;
+
 		/* Don't backtrack into a point where the thread is disabled or sleeping. */
-		if (node->get_enabled_array()[i]!=THREAD_ENABLED)
+		if (node->enabled_status(tid)!=THREAD_ENABLED)
 			continue;
 	
 		/* Check if this has been explored already */
@@ -441,7 +445,7 @@ ModelAction * ModelChecker::get_next_backtrack()
  */
 bool ModelChecker::process_read(ModelAction *curr, bool second_part_of_rmw)
 {
-	uint64_t value;
+	uint64_t value = VALUE_NONE;
 	bool updated = false;
 	while (true) {
 		const ModelAction *reads_from = curr->get_node()->get_read_from();
@@ -744,41 +748,46 @@ void ModelChecker::process_relseq_fixup(ModelAction *curr, work_queue_t *work_qu
  * initializing clock vectors, and computing the promises to fulfill.
  *
  * @param curr The current action, as passed from the user context; may be
- * freed/invalidated after the execution of this function
- * @return The current action, as processed by the ModelChecker. Is only the
- * same as the parameter @a curr if this is a newly-explored action.
+ * freed/invalidated after the execution of this function, with a different
+ * action "returned" its place (pass-by-reference)
+ * @return True if curr is a newly-explored action; false otherwise
  */
-ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr)
+bool ModelChecker::initialize_curr_action(ModelAction **curr)
 {
 	ModelAction *newcurr;
 
-	if (curr->is_rmwc() || curr->is_rmw()) {
-		newcurr = process_rmw(curr);
-		delete curr;
+	if ((*curr)->is_rmwc() || (*curr)->is_rmw()) {
+		newcurr = process_rmw(*curr);
+		delete *curr;
 
 		if (newcurr->is_rmw())
 			compute_promises(newcurr);
-		return newcurr;
+
+		*curr = newcurr;
+		return false;
 	}
 
-	curr->set_seq_number(get_next_seq_num());
+	(*curr)->set_seq_number(get_next_seq_num());
 
-	newcurr = node_stack->explore_action(curr, scheduler->get_enabled());
+	newcurr = node_stack->explore_action(*curr, scheduler->get_enabled());
 	if (newcurr) {
 		/* First restore type and order in case of RMW operation */
-		if (curr->is_rmwr())
-			newcurr->copy_typeandorder(curr);
+		if ((*curr)->is_rmwr())
+			newcurr->copy_typeandorder(*curr);
 
-		ASSERT(curr->get_location() == newcurr->get_location());
-		newcurr->copy_from_new(curr);
+		ASSERT((*curr)->get_location() == newcurr->get_location());
+		newcurr->copy_from_new(*curr);
 
 		/* Discard duplicate ModelAction; use action from NodeStack */
-		delete curr;
+		delete *curr;
 
 		/* Always compute new clock vector */
 		newcurr->create_cv(get_parent_action(newcurr->get_tid()));
+
+		*curr = newcurr;
+		return false; /* Action was explored previously */
 	} else {
-		newcurr = curr;
+		newcurr = *curr;
 
 		/* Always compute new clock vector */
 		newcurr->create_cv(get_parent_action(newcurr->get_tid()));
@@ -795,8 +804,8 @@ ModelAction * ModelChecker::initialize_curr_action(ModelAction *curr)
 		else if (newcurr->is_notify_one()) {
 			newcurr->get_node()->set_misc_max(condvar_waiters_map->get_safe_ptr(newcurr->get_location())->size());
 		}
+		return true; /* This was a new ModelAction */
 	}
-	return newcurr;
 }
 
 /**
@@ -854,18 +863,17 @@ Thread * ModelChecker::check_current_action(ModelAction *curr)
 		return get_next_thread(NULL);
 	}
 
-	ModelAction *newcurr = initialize_curr_action(curr);
+	bool newly_explored = initialize_curr_action(&curr);
 
 	wake_up_sleeping_actions(curr);
 
 	/* Add the action to lists before any other model-checking tasks */
 	if (!second_part_of_rmw)
-		add_action_to_lists(newcurr);
+		add_action_to_lists(curr);
 
 	/* Build may_read_from set for newly-created actions */
-	if (curr == newcurr && curr->is_read())
+	if (newly_explored && curr->is_read())
 		build_reads_from_past(curr);
-	curr = newcurr;
 
 	/* Initialize work_queue with the "current action" work */
 	work_queue_t work_queue(1, CheckCurrWorkEntry(curr));
@@ -1086,7 +1094,7 @@ void ModelChecker::check_recency(ModelAction *curr, const ModelAction *rf) {
 				ModelAction *act=*rit;
 				bool foundvalue = false;
 				for (int j = 0; j<act->get_node()->get_read_from_size(); j++) {
-					if (act->get_node()->get_read_from_at(i)==write) {
+					if (act->get_node()->get_read_from_at(j)==write) {
 						foundvalue = true;
 						break;
 					}
@@ -1366,32 +1374,40 @@ bool ModelChecker::thin_air_constraint_may_allow(const ModelAction * writer, con
 	return true;
 }
 
-/** Arbitrary reads from the future are not allowed.  Section 29.3
- * part 9 places some constraints.  This method checks one result of constraint
- * constraint.  Others require compiler support. */
-bool ModelChecker::mo_may_allow(const ModelAction * writer, const ModelAction *reader) {
+/**
+ * Arbitrary reads from the future are not allowed. Section 29.3 part 9 places
+ * some constraints. This method checks one the following constraint (others
+ * require compiler support):
+ *
+ *   If X --hb-> Y --mo-> Z, then X should not read from Z.
+ */
+bool ModelChecker::mo_may_allow(const ModelAction *writer, const ModelAction *reader)
+{
 	std::vector<action_list_t> *thrd_lists = obj_thrd_map->get_safe_ptr(reader->get_location());
+	unsigned int i;
 
-	//Get write that follows reader action
-	action_list_t *list = &(*thrd_lists)[id_to_int(reader->get_tid())];
-	action_list_t::reverse_iterator rit;
-	ModelAction *first_write_after_read=NULL;
-
-	for (rit = list->rbegin(); rit != list->rend(); rit++) {
-		ModelAction *act = *rit;
-		if (act==reader)
-			break;
-		if (act->is_write())
-			first_write_after_read=act;
-	}
+	/* Iterate over all threads */
+	for (i = 0; i < thrd_lists->size(); i++) {
+		ModelAction *write_after_read = NULL;
 
-	if (first_write_after_read==NULL)
-		return true;
+		/* Iterate over actions in thread, starting from most recent */
+		action_list_t *list = &(*thrd_lists)[i];
+		action_list_t::reverse_iterator rit;
+		for (rit = list->rbegin(); rit != list->rend(); rit++) {
+			ModelAction *act = *rit;
 
-	return !mo_graph->checkReachable(first_write_after_read, writer);
-}
+			if (!reader->happens_before(act))
+				break;
+			else if (act->is_write())
+				write_after_read = act;
+		}
 
+		if (write_after_read && mo_graph->checkReachable(write_after_read, writer))
+			return false;
+	}
 
+	return true;
+}
 
 /**
  * Finds the head(s) of the release sequence(s) containing a given ModelAction.
@@ -1815,6 +1831,7 @@ void ModelChecker::compute_promises(ModelAction *curr)
 				act->is_read() &&
 				!act->could_synchronize_with(curr) &&
 				!act->same_thread(curr) &&
+				act->get_location() == curr->get_location() &&
 				promise->get_value() == curr->get_value()) {
 			curr->get_node()->set_promise(i);
 		}
@@ -1993,6 +2010,7 @@ void ModelChecker::build_reads_from_past(ModelAction *curr)
 	if (!initialized) {
 		/** @todo Need a more informative way of reporting errors. */
 		printf("ERROR: may read from uninitialized atomic\n");
+		set_assert();
 	}
 
 	if (DBG_ENABLED() || !initialized) {
@@ -2002,14 +2020,13 @@ void ModelChecker::build_reads_from_past(ModelAction *curr)
 		curr->get_node()->print_may_read_from();
 		printf("End printing may_read_from\n");
 	}
-
-	ASSERT(initialized);
 }
 
 bool ModelChecker::sleep_can_read_from(ModelAction * curr, const ModelAction *write) {
 	while(true) {
 		Node *prevnode=write->get_node()->get_parent();
-		bool thread_sleep=prevnode->get_enabled_array()[id_to_int(curr->get_tid())]==THREAD_SLEEP_SET;
+		
+		bool thread_sleep=prevnode->enabled_status(curr->get_tid())==THREAD_SLEEP_SET;
 		if (write->is_release()&&thread_sleep)
 			return true;
 		if (!write->is_rmw()) {