be even more aggressive about sleep sets...
[model-checker.git] / model.cc
index d77ba4b..f8482cb 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -179,7 +179,6 @@ Thread * ModelChecker::get_next_thread(ModelAction *curr)
                        scheduler->add_sleep(thread_map->get(id_to_int(next->get_tid())));
                        tid = prevnode->get_next_backtrack();
                        /* Make sure the backtracked thread isn't sleeping. */
-                       scheduler->remove_sleep(thread_map->get(id_to_int(tid)));
                        node_stack->pop_restofstack(1);
                        if (diverge==earliest_diverge) {
                                earliest_diverge=prevnode->get_action();
@@ -213,6 +212,7 @@ void ModelChecker::execute_sleep_set() {
                        thr->set_state(THREAD_RUNNING);
                        scheduler->next_thread(thr);
                        Thread::swap(&system_context, thr);
+                       priv->current_action->set_sleep_flag();
                        thr->set_pending(priv->current_action);
                }
        }
@@ -346,7 +346,8 @@ void ModelChecker::set_backtracking(ModelAction *act)
        for(int i = low_tid; i < high_tid; i++) {
                thread_id_t tid = int_to_id(i);
 
-               if (!node->is_enabled(tid))
+               /* Don't backtrack into a point where the thread is disabled or sleeping. */
+               if (node->get_enabled_array()[i]!=THREAD_ENABLED)
                        continue;
        
                /* Check if this has been explored already */
@@ -1846,7 +1847,12 @@ void ModelChecker::build_reads_from_past(ModelAction *curr)
                                        act->print();
                                        curr->print();
                                }
-                               curr->get_node()->add_read_from(act);
+
+                               if (curr->get_sleep_flag()) {
+                                       if (sleep_can_read_from(curr, act))
+                                               curr->get_node()->add_read_from(act);
+                               } else
+                                       curr->get_node()->add_read_from(act);
                        }
 
                        /* Include at most one act per-thread that "happens before" curr */
@@ -1873,6 +1879,20 @@ void ModelChecker::build_reads_from_past(ModelAction *curr)
        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;
+               if (write->is_release()&&thread_sleep)
+                       return true;
+               if (!write->is_rmw())
+                       return false;
+               if (write->get_reads_from()==NULL)
+                       return true;
+               write=write->get_reads_from();
+       }
+}
+
 static void print_list(action_list_t *list)
 {
        action_list_t::iterator it;