+
+/**
+ * Takes the next step in the execution, if possible.
+ * @return Returns true (success) if a step was taken and false otherwise.
+ */
+bool ModelChecker::take_step() {
+ Thread *curr, *next;
+
+ curr = thread_current();
+ if (curr) {
+ if (curr->get_state() == THREAD_READY) {
+ check_current_action();
+ scheduler->add_thread(curr);
+ } else if (curr->get_state() == THREAD_RUNNING) {
+ /* Stopped while running; i.e., completed */
+ curr->complete();
+ } else {
+ ASSERT(false);
+ }
+ }
+ next = scheduler->next_thread();
+
+ /* Infeasible -> don't take any more steps */
+ if (!isfeasible())
+ return false;
+
+ if (next)
+ next->set_state(THREAD_RUNNING);
+ DEBUG("(%d, %d)\n", curr ? curr->get_id() : -1, next ? next->get_id() : -1);
+
+ /* next == NULL -> don't take any more steps */
+ if (!next)
+ return false;
+ /* Return false only if swap fails with an error */
+ return (Thread::swap(get_system_context(), next) == 0);
+}
+
+/** Runs the current execution until threre are no more steps to take. */
+void ModelChecker::finish_execution() {
+ DBG();
+
+ while (take_step());
+}