fix sleeping bug
authorDerek Yeh <djyeh@plrg-1.ics.uci.edu>
Sun, 2 Aug 2020 06:44:39 +0000 (23:44 -0700)
committerDerek Yeh <djyeh@plrg-1.ics.uci.edu>
Sun, 2 Aug 2020 06:44:39 +0000 (23:44 -0700)
model.cc
model.h

index 2f744ee..d3692c4 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -354,23 +354,34 @@ void ModelChecker::continueExecution(Thread *old)
        thread_chosen = false;
        curr_thread_num = 1;
        Thread *thr = getNextThread();
-       scheduler->set_current_thread(thr);
-       if (Thread::swap(old, thr) < 0) {
-               perror("swap threads");
-               exit(EXIT_FAILURE);
-       }
+       if (thr != nullptr) {
+               scheduler->set_current_thread(thr);
+               if (Thread::swap(old, thr) < 0) {
+                       perror("swap threads");
+                       exit(EXIT_FAILURE);
+               }
+       } else
+               handleChosenThread(old);        
 }
 
 Thread* ModelChecker::getNextThread()
 {
-       Thread *thr = NULL;
+       Thread *thr = nullptr;
        for (unsigned int i = curr_thread_num; i < get_num_threads(); i++) {
                thread_id_t tid = int_to_id(i);
                thr = get_thread(tid);
+               
                if (!thr->is_complete() && !thr->get_pending()) {
                        curr_thread_num = i;
                        break;
                }
+               ModelAction *act = thr->get_pending();
+               
+               if (act && execution->is_enabled(thr) && !execution->check_action_enabled(act)) {
+                       scheduler->sleep(thr);
+               }
+
+               chooseThread(act, thr);
        }
        return thr;
 }
@@ -391,6 +402,26 @@ void ModelChecker::consumeAction()
        chosen_thread = execution->take_step(curr);
 }
 
+void ModelChecker::chooseThread(ModelAction *act, Thread *old)
+{
+       if (!thread_chosen && act && execution->is_enabled(old) && (old->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) {
+                               chosen_thread = old;
+                               thread_chosen = true;
+                       }
+               } else if (act->get_type() == THREAD_CREATE || \
+                                                       act->get_type() == PTHREAD_CREATE || \
+                                                       act->get_type() == THREAD_START || \
+                                                       act->get_type() == THREAD_FINISH) {
+                       chosen_thread = old;
+                       thread_chosen = true;
+               }
+       }       
+}
+
 uint64_t ModelChecker::switch_thread(ModelAction *act)
 {
        if (modellock) {
@@ -415,68 +446,60 @@ uint64_t ModelChecker::switch_thread(ModelAction *act)
 
        curr_thread_num++;
        Thread* next = getNextThread();
+       if (next != nullptr) 
+               handleNewValidThread(old, next);
+       else
+               handleChosenThread(old);
+
+       return old->get_return_value();
+}
 
+void ModelChecker::handleNewValidThread(Thread *old, Thread *next)
+{
        if (old->is_waiting_on(old))
                assert_bug("Deadlock detected (thread %u)", curr_thread_num-1);
 
-       ModelAction *act2 = old->get_pending();
+       ModelAction *act = old->get_pending();
                
-       if (act2 && execution->is_enabled(old) && !execution->check_action_enabled(act2)) {
+       if (act && execution->is_enabled(old) && !execution->check_action_enabled(act)) {
                scheduler->sleep(old);
        }
-       if (!thread_chosen && act2 && execution->is_enabled(old) && (old->get_state() != THREAD_BLOCKED) ) {
-               if (act2->is_write()) {
-                       std::memory_order order = act2->get_mo();
-                       if (order == std::memory_order_relaxed || \
-                                       order == std::memory_order_release) {
-                               chosen_thread = old;
-                               thread_chosen = true;
-                       }
-               } else if (act2->get_type() == THREAD_CREATE || \
-                                                       act2->get_type() == PTHREAD_CREATE || \
-                                                       act2->get_type() == THREAD_START || \
-                                                       act2->get_type() == THREAD_FINISH) {
-                       chosen_thread = old;
-                       thread_chosen = true;
-               }
-       }
+       chooseThread(act, old);
 
-       if (curr_thread_num < get_num_threads()) {
-               scheduler->set_current_thread(next);    
+       scheduler->set_current_thread(next);    
 
-               if (Thread::swap(old, next) < 0) {
-                       perror("swap threads");
-                       exit(EXIT_FAILURE);
-               }               
-       } else {
-               
-               if (execution->has_asserted())
+       if (Thread::swap(old, next) < 0) {
+               perror("swap threads");
+               exit(EXIT_FAILURE);
+       }               
+}
+
+void ModelChecker::handleChosenThread(Thread *old)
+{
+       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;
+               // Allow this thread to stash the next pending action
+               if (should_terminate_execution())
                        finishExecution(old);
-               if (!chosen_thread)
-                       chosen_thread = get_next_thread();
-               if (!chosen_thread || chosen_thread->is_model_thread())
+               else
+                       continueExecution(old); 
+       } else {
+               /* Consume the next action for a Thread */
+               consumeAction();
+
+               if (should_terminate_execution())
                        finishExecution(old);
-               if (chosen_thread->just_woken_up()) {
-                       chosen_thread->set_wakeup_state(false);
-                       chosen_thread->set_pending(NULL);
-                       chosen_thread = NULL;
-                       // Allow this thread to stash the next pending action
-                       if (should_terminate_execution())
-                               finishExecution(old);
-                       else
-                               continueExecution(old); 
-               } else {
-                       /* Consume the next action for a Thread */
-                       consumeAction();
-
-                       if (should_terminate_execution())
-                               finishExecution(old);
-                       else
-                               continueExecution(old);         
-               }               
-               
+               else
+                       continueExecution(old);         
        }
-       return old->get_return_value();
 }
 
 static void runChecker() {
diff --git a/model.h b/model.h
index cabd990..b81858c 100644 (file)
--- a/model.h
+++ b/model.h
@@ -58,7 +58,10 @@ public:
        void continueExecution(Thread *old);
        void finishExecution(Thread *old);
        void consumeAction();
+       void chooseThread(ModelAction *act, Thread *old);
        Thread * getNextThread();
+       void handleChosenThread(Thread *old);
+       void handleNewValidThread(Thread *old, Thread *next);
 
        void assert_bug(const char *msg, ...);