remove overhead for execution
authorDerek Yeh <djyeh@plrg-1.ics.uci.edu>
Mon, 27 Jul 2020 00:03:51 +0000 (17:03 -0700)
committerDerek Yeh <djyeh@plrg-1.ics.uci.edu>
Mon, 27 Jul 2020 00:03:51 +0000 (17:03 -0700)
model.cc
model.h

index ad2e0d9..2aacaa2 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -344,6 +344,39 @@ uint64_t ModelChecker::switch_to_master(ModelAction *act)
        return old->get_return_value();
 }
 
+void ModelChecker::continueExecution(Thread *old) 
+{
+       if (params.traceminsize != 0 &&
+                       execution->get_curr_seq_num() > checkfree) {
+               checkfree += params.checkthreshold;
+               execution->collectActions();
+       }
+       curr_thread_num = 0;
+       thread_id_t tid = int_to_id(0);
+       Thread *thr = get_thread(tid);
+       scheduler->set_current_thread(thr);
+       if (Thread::swap(old, thr) < 0) {
+               perror("swap threads");
+               exit(EXIT_FAILURE);
+       }
+}
+
+void ModelChecker::finishExecution(Thread *old) 
+{
+       scheduler->set_current_thread(NULL);
+       if (Thread::swap(old, &system_context) < 0) {
+               perror("swap threads");
+               exit(EXIT_FAILURE);
+       }
+}
+
+void ModelChecker::consumeAction()
+{
+       ModelAction *curr = chosen_thread->get_pending();
+       chosen_thread->set_pending(NULL);
+       chosen_thread = execution->take_step(curr);
+}
+
 uint64_t ModelChecker::switch_thread(ModelAction *act)
 {
        if (modellock) {
@@ -407,12 +440,27 @@ uint64_t ModelChecker::switch_thread(ModelAction *act)
                        exit(EXIT_FAILURE);
                }               
        } else {
-               scheduler->set_current_thread(NULL);
+               if (execution->has_asserted())
+                       finishExecution(old);
+               if (!chosen_thread)
+                       chosen_thread = get_next_thread();
+               if (!chosen_thread || chosen_thread->is_model_thread())
+                       finishExecution(old);
+               if (chosen_thread->just_woken_up()) {
+                       chosen_thread->set_wakeup_state(false);
+                       chosen_thread->set_pending(NULL);
+                       chosen_thread = NULL;
+                       continueExecution(old); // Allow this thread to stash the next pending action
+               } else {
+                       /* Consume the next action for a Thread */
+                       consumeAction();
 
-               if (Thread::swap(old, &system_context) < 0) {
-                       perror("swap threads");
-                       exit(EXIT_FAILURE);
-               }
+                       if (should_terminate_execution())
+                               finishExecution(old);
+                       else
+                               continueExecution(old);         
+               }               
+               
        }
        return old->get_return_value();
 }
@@ -445,91 +493,14 @@ void ModelChecker::run()
        //Need to initial random number generator state to avoid resets on rollback
        char random_state[256];
        initstate(423121, random_state, sizeof(random_state));
-       modelclock_t checkfree = params.checkthreshold;
+       checkfree = params.checkthreshold;
        for(int exec = 0;exec < params.maxexecutions;exec++) {
                chosen_thread = init_thread;
                thread_chosen = false;
-               do {
-                       /* Check whether we need to free model actions. */
-
-                       if (params.traceminsize != 0 &&
-                                       execution->get_curr_seq_num() > checkfree) {
-                               checkfree += params.checkthreshold;
-                               execution->collectActions();
-                       }
-
-                       /*
-                        * Stash next pending action(s) for thread(s). There
-                        * should only need to stash one thread's action--the
-                        * thread which just took a step--plus the first step
-                        * for any newly-created thread
-                        */
-                       curr_thread_num = 0;
-                       thread_id_t tid = int_to_id(0);
-                       Thread *thr = get_thread(tid);
-                       switch_from_master(thr);
-                       /*
-                       for (unsigned int i = 0;i < get_num_threads();i++) {
-                               thread_id_t tid = int_to_id(i);
-                               Thread *thr = get_thread(tid);
-                               if (!thr->is_model_thread() && !thr->is_complete() && !thr->get_pending()) {
-                                       switch_from_master(thr);
-                                       if (thr->is_waiting_on(thr))
-                                               assert_bug("Deadlock detected (thread %u)", i);
-                               }
-                       }
-                       */
-                       /* Don't schedule threads which should be disabled */
-                       /*for (unsigned int i = 0;i < get_num_threads();i++) {
-                               Thread *th = get_thread(int_to_id(i));
-                               ModelAction *act = th->get_pending();
-                               if (act && execution->is_enabled(th) && !execution->check_action_enabled(act)) {
-                                       scheduler->sleep(th);
-                               }
-                       }
-                       */
-                       /*for (unsigned int i = 1;i < get_num_threads();i++) {
-                               Thread *th = get_thread(int_to_id(i));
-                               ModelAction *act = th->get_pending();
-                               if (act && execution->is_enabled(th) && (th->get_state() != THREAD_BLOCKED) ) {
-                                       if (act->is_write()) {
-                                               std::memory_order order = act->get_mo();
-                                               if (order == std::memory_order_relaxed || \
-                                                               order == std::memory_order_release) {
-                                                       t = th;
-                                                       break;
-                                               }
-                                       } else if (act->get_type() == THREAD_CREATE || \
-                                                                                act->get_type() == PTHREAD_CREATE || \
-                                                                                act->get_type() == THREAD_START || \
-                                                                                act->get_type() == THREAD_FINISH) {
-                                               t = th;
-                                               break;
-                                       }
-                               }
-                       }
-                       */
-                       /* Catch assertions from prior take_step or from
-                       * between-ModelAction bugs (e.g., data races) */
-
-                       if (execution->has_asserted())
-                               break;
-                       if (!chosen_thread)
-                               chosen_thread = get_next_thread();
-                       if (!chosen_thread || chosen_thread->is_model_thread())
-                               break;
-                       if (chosen_thread->just_woken_up()) {
-                               chosen_thread->set_wakeup_state(false);
-                               chosen_thread->set_pending(NULL);
-                               chosen_thread = NULL;
-                               continue;       // Allow this thread to stash the next pending action
-                       }
-
-                       /* Consume the next action for a Thread */
-                       ModelAction *curr = chosen_thread->get_pending();
-                       chosen_thread->set_pending(NULL);
-                       chosen_thread = execution->take_step(curr);
-               } while (!should_terminate_execution());
+               curr_thread_num = 0;
+               thread_id_t tid = int_to_id(0);
+               Thread *thr = get_thread(tid);
+               switch_from_master(thr);
                finish_execution((exec+1) < params.maxexecutions);
                //restore random number generator state after rollback
                setstate(random_state);
diff --git a/model.h b/model.h
index ed364b1..dc36eb6 100644 (file)
--- a/model.h
+++ b/model.h
@@ -55,6 +55,10 @@ public:
        uint64_t switch_to_master(ModelAction *act);
        uint64_t switch_thread(ModelAction *act);
 
+       void continueExecution(Thread *old);
+       void finishExecution(Thread *old);
+       void consumeAction();
+
        void assert_bug(const char *msg, ...);
 
        void assert_user_bug(const char *msg);
@@ -84,6 +88,8 @@ private:
 
        bool thread_chosen;
 
+       modelclock_t checkfree;
+
        unsigned int get_num_threads() const;
 
        void finish_execution(bool moreexecutions);