Merge branch 'new_fuzzer' of ssh://plrg.eecs.uci.edu:/home/git/random-fuzzer into...
[c11tester.git] / execution.cc
index 968eacf01324add645aadade3fafd076821fa860..c32b628876fc22ccf3a4aba46d2839f182f99965 100644 (file)
@@ -28,7 +28,6 @@ struct model_snapshot_members {
                used_sequence_numbers(0),
                bugs(),
                bad_synchronization(false),
-               bad_sc_read(false),
                asserted(false)
        { }
 
@@ -43,16 +42,13 @@ struct model_snapshot_members {
        SnapVector<bug_message *> bugs;
        /** @brief Incorrectly-ordered synchronization was made */
        bool bad_synchronization;
-       bool bad_sc_read;
        bool asserted;
 
        SNAPSHOTALLOC
 };
 
 /** @brief Constructor */
-ModelExecution::ModelExecution(ModelChecker *m,
-                                                                                                                        Scheduler *scheduler,
-                                                                                                                        NodeStack *node_stack) :
+ModelExecution::ModelExecution(ModelChecker *m, Scheduler *scheduler, NodeStack *node_stack) :
        model(m),
        params(NULL),
        scheduler(scheduler),
@@ -68,7 +64,7 @@ ModelExecution::ModelExecution(ModelChecker *m,
        thrd_last_fence_release(),
        node_stack(node_stack),
        priv(new struct model_snapshot_members ()),
-                        mo_graph(new CycleGraph()),
+       mo_graph(new CycleGraph()),
        fuzzer(new Fuzzer())
 {
        /* Initialize a model-checker thread, for special ModelActions */
@@ -113,18 +109,6 @@ static SnapVector<action_list_t> * get_safe_ptr_vect_action(HashTable<void *, Sn
        return tmp;
 }
 
-action_list_t * ModelExecution::get_actions_on_obj(void * obj, thread_id_t tid) const
-{
-       SnapVector<action_list_t> *wrv = obj_thrd_map.get(obj);
-       if (wrv==NULL)
-               return NULL;
-       unsigned int thread=id_to_int(tid);
-       if (thread < wrv->size())
-               return &(*wrv)[thread];
-       else
-               return NULL;
-}
-
 /** @return a thread ID for a new Thread */
 thread_id_t ModelExecution::get_next_id()
 {
@@ -190,13 +174,6 @@ void ModelExecution::set_bad_synchronization()
        priv->bad_synchronization = true;
 }
 
-/** @brief Alert the model-checker that an incorrectly-ordered
- * synchronization was made */
-void ModelExecution::set_bad_sc_read()
-{
-       priv->bad_sc_read = true;
-}
-
 bool ModelExecution::assert_bug(const char *msg)
 {
        priv->bugs.push_back(new bug_message(msg));
@@ -283,8 +260,9 @@ bool ModelExecution::is_complete_execution() const
  * @param rf_set is the set of model actions we can possibly read from
  * @return True if processing this read updates the mo_graph.
  */
-bool ModelExecution::process_read(ModelAction *curr, ModelVector<ModelAction *> * rf_set)
+void ModelExecution::process_read(ModelAction *curr, SnapVector<const ModelAction *> * rf_set)
 {
+       SnapVector<const ModelAction *> * priorset = new SnapVector<const ModelAction *>();
        while(true) {
 
                int index = fuzzer->selectWrite(curr, rf_set);
@@ -292,16 +270,21 @@ bool ModelExecution::process_read(ModelAction *curr, ModelVector<ModelAction *>
 
 
                ASSERT(rf);
-
-               mo_graph->startChanges();
-               bool updated = r_modification_order(curr, rf);
-               if (!is_infeasible()) {
+               bool canprune = false;
+               if (r_modification_order(curr, rf, priorset, &canprune)) {
+                       for(unsigned int i=0;i<priorset->size();i++) {
+                               mo_graph->addEdge((*priorset)[i], rf);
+                       }
                        read_from(curr, rf);
-                       mo_graph->commitChanges();
                        get_thread(curr)->set_return_value(curr->get_return_value());
-                       return updated;
+                       delete priorset;
+                       if (canprune && curr->get_type() == ATOMIC_READ) {
+                         int tid = id_to_int(curr->get_tid());
+                         (*obj_thrd_map.get(curr->get_location()))[tid].pop_back();
+                       }
+                       return;
                }
-               mo_graph->rollbackChanges();
+               priorset->clear();
                (*rf_set)[index] = rf_set->back();
                rf_set->pop_back();
        }
@@ -383,8 +366,10 @@ bool ModelExecution::process_mutex(ModelAction *curr)
        }
        case ATOMIC_NOTIFY_ONE: {
                action_list_t *waiters = get_safe_ptr_action(&condvar_waiters_map, curr->get_location());
-               Thread * thread = fuzzer->selectNotify(waiters);
-               scheduler->wake(thread);
+               if (waiters->size() != 0) {
+                       Thread * thread = fuzzer->selectNotify(waiters);
+                       scheduler->wake(thread);
+               }
                break;
        }
 
@@ -399,15 +384,13 @@ bool ModelExecution::process_mutex(ModelAction *curr)
  * @param curr The ModelAction to process
  * @return True if the mo_graph was updated or promises were resolved
  */
-bool ModelExecution::process_write(ModelAction *curr)
+void ModelExecution::process_write(ModelAction *curr)
 {
 
-       bool updated_mod_order = w_modification_order(curr);
+       w_modification_order(curr);
 
-       mo_graph->commitChanges();
 
        get_thread(curr)->set_return_value(VALUE_NONE);
-       return updated_mod_order;
 }
 
 /**
@@ -693,10 +676,10 @@ ModelAction * ModelExecution::check_current_action(ModelAction *curr)
        wake_up_sleeping_actions(curr);
 
        /* Add the action to lists before any other model-checking tasks */
-       if (!second_part_of_rmw)
+       if (!second_part_of_rmw && curr->get_type() != NOOP)
                add_action_to_lists(curr);
 
-       ModelVector<ModelAction *> * rf_set = NULL;
+       SnapVector<const ModelAction *> * rf_set = NULL;
        /* Build may_read_from set for newly-created actions */
        if (newly_explored && curr->is_read())
                rf_set = build_may_read_from(curr);
@@ -741,12 +724,8 @@ void ModelExecution::print_infeasibility(const char *prefix) const
 {
        char buf[100];
        char *ptr = buf;
-       if (mo_graph->checkForCycles())
-               ptr += sprintf(ptr, "[mo cycle]");
        if (priv->bad_synchronization)
                ptr += sprintf(ptr, "[bad sw ordering]");
-       if (priv->bad_sc_read)
-               ptr += sprintf(ptr, "[bad sc read]");
        if (ptr != buf)
                model_print("%s: %s", prefix ? prefix : "Infeasible", buf);
 }
@@ -759,9 +738,7 @@ void ModelExecution::print_infeasibility(const char *prefix) const
  */
 bool ModelExecution::is_infeasible() const
 {
-       return mo_graph->checkForCycles() ||
-                                priv->bad_synchronization ||
-                                priv->bad_sc_read;
+       return priv->bad_synchronization;
 }
 
 /** Close out a RMWR by converting previous RMWR into a RMW or READ. */
@@ -770,7 +747,6 @@ ModelAction * ModelExecution::process_rmw(ModelAction *act) {
        lastread->process_rmw(act);
        if (act->is_rmw()) {
                mo_graph->addRMWEdge(lastread->get_reads_from(), lastread);
-               mo_graph->commitChanges();
        }
        return lastread;
 }
@@ -791,12 +767,11 @@ ModelAction * ModelExecution::process_rmw(ModelAction *act) {
  * @param rf The ModelAction or Promise that curr reads from. Must be a write.
  * @return True if modification order edges were added; false otherwise
  */
-template <typename rf_type>
-bool ModelExecution::r_modification_order(ModelAction *curr, const rf_type *rf)
+
+bool ModelExecution::r_modification_order(ModelAction *curr, const ModelAction *rf, SnapVector<const ModelAction *> * priorset, bool * canprune)
 {
        SnapVector<action_list_t> *thrd_lists = obj_thrd_map.get(curr->get_location());
        unsigned int i;
-       bool added = false;
        ASSERT(curr->is_read());
 
        /* Last SC fence in the current thread */
@@ -805,20 +780,29 @@ bool ModelExecution::r_modification_order(ModelAction *curr, const rf_type *rf)
        if (curr->is_seqcst())
                last_sc_write = get_last_seq_cst_write(curr);
 
+       int tid = curr->get_tid();
+       ModelAction *prev_same_thread = NULL;
        /* Iterate over all threads */
-       for (i = 0;i < thrd_lists->size();i++) {
-               /* Last SC fence in thread i */
+       for (i = 0;i < thrd_lists->size();i++, tid = (((unsigned int)(tid+1)) == thrd_lists->size()) ? 0: tid + 1) {
+               /* Last SC fence in thread tid */
                ModelAction *last_sc_fence_thread_local = NULL;
-               if (int_to_id((int)i) != curr->get_tid())
-                       last_sc_fence_thread_local = get_last_seq_cst_fence(int_to_id(i), NULL);
+               if (i != 0)
+                       last_sc_fence_thread_local = get_last_seq_cst_fence(int_to_id(tid), NULL);
 
-               /* Last SC fence in thread i, before last SC fence in current thread */
+               /* Last SC fence in thread tid, before last SC fence in current thread */
                ModelAction *last_sc_fence_thread_before = NULL;
                if (last_sc_fence_local)
-                       last_sc_fence_thread_before = get_last_seq_cst_fence(int_to_id(i), last_sc_fence_local);
+                       last_sc_fence_thread_before = get_last_seq_cst_fence(int_to_id(tid), last_sc_fence_local);
 
+               //Only need to iterate if either hb has changed for thread in question or SC fence after last operation...
+               if (prev_same_thread != NULL &&
+                   (prev_same_thread->get_cv()->getClock(tid) == curr->get_cv()->getClock(tid)) &&
+                   (last_sc_fence_thread_local == NULL || *last_sc_fence_thread_local < *prev_same_thread)) {
+                     continue;
+               }
+               
                /* Iterate over actions in thread, starting from most recent */
-               action_list_t *list = &(*thrd_lists)[i];
+               action_list_t *list = &(*thrd_lists)[tid];
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin();rit != list->rend();rit++) {
                        ModelAction *act = *rit;
@@ -838,19 +822,25 @@ bool ModelExecution::r_modification_order(ModelAction *curr, const rf_type *rf)
                                /* C++, Section 29.3 statement 5 */
                                if (curr->is_seqcst() && last_sc_fence_thread_local &&
                                                *act < *last_sc_fence_thread_local) {
-                                       added = mo_graph->addEdge(act, rf) || added;
+                                       if (mo_graph->checkReachable(rf, act))
+                                               return false;
+                                       priorset->push_back(act);
                                        break;
                                }
                                /* C++, Section 29.3 statement 4 */
                                else if (act->is_seqcst() && last_sc_fence_local &&
                                                                 *act < *last_sc_fence_local) {
-                                       added = mo_graph->addEdge(act, rf) || added;
+                                       if (mo_graph->checkReachable(rf, act))
+                                               return false;
+                                       priorset->push_back(act);
                                        break;
                                }
                                /* C++, Section 29.3 statement 6 */
                                else if (last_sc_fence_thread_before &&
                                                                 *act < *last_sc_fence_thread_before) {
-                                       added = mo_graph->addEdge(act, rf) || added;
+                                       if (mo_graph->checkReachable(rf, act))
+                                               return false;
+                                       priorset->push_back(act);
                                        break;
                                }
                        }
@@ -860,19 +850,34 @@ bool ModelExecution::r_modification_order(ModelAction *curr, const rf_type *rf)
                         * before" curr
                         */
                        if (act->happens_before(curr)) {
+                         if (i==0) {
+                           if (last_sc_fence_local == NULL ||
+                               (*last_sc_fence_local < *prev_same_thread)) {
+                             prev_same_thread = act;
+                           }
+                         }
                                if (act->is_write()) {
-                                       added = mo_graph->addEdge(act, rf) || added;
+                                       if (mo_graph->checkReachable(rf, act))
+                                               return false;
+                                       priorset->push_back(act);
                                } else {
                                        const ModelAction *prevrf = act->get_reads_from();
-                                       if (!prevrf->equals(rf))
-                                               added = mo_graph->addEdge(prevrf, rf) || added;
+                                       if (!prevrf->equals(rf)) {
+                                               if (mo_graph->checkReachable(rf, prevrf))
+                                                       return false;
+                                               priorset->push_back(prevrf);
+                                       } else {
+                                               if (act->get_tid() == curr->get_tid()) {
+                                                       //Can prune curr from obj list
+                                                       *canprune = true;
+                                               }
+                                       }
                                }
                                break;
                        }
                }
        }
-
-       return added;
+       return true;
 }
 
 /**
@@ -899,11 +904,10 @@ bool ModelExecution::r_modification_order(ModelAction *curr, const rf_type *rf)
  * value. If NULL, then don't record any future values.
  * @return True if modification order edges were added; false otherwise
  */
-bool ModelExecution::w_modification_order(ModelAction *curr)
+void ModelExecution::w_modification_order(ModelAction *curr)
 {
        SnapVector<action_list_t> *thrd_lists = obj_thrd_map.get(curr->get_location());
        unsigned int i;
-       bool added = false;
        ASSERT(curr->is_write());
 
        if (curr->is_seqcst()) {
@@ -911,7 +915,7 @@ bool ModelExecution::w_modification_order(ModelAction *curr)
                         so we are initialized. */
                ModelAction *last_seq_cst = get_last_seq_cst_write(curr);
                if (last_seq_cst != NULL) {
-                       added = mo_graph->addEdge(last_seq_cst, curr) || added;
+                       mo_graph->addEdge(last_seq_cst, curr);
                }
        }
 
@@ -928,6 +932,7 @@ bool ModelExecution::w_modification_order(ModelAction *curr)
                /* Iterate over actions in thread, starting from most recent */
                action_list_t *list = &(*thrd_lists)[i];
                action_list_t::reverse_iterator rit;
+               bool force_edge = false;
                for (rit = list->rbegin();rit != list->rend();rit++) {
                        ModelAction *act = *rit;
                        if (act == curr) {
@@ -942,6 +947,7 @@ bool ModelExecution::w_modification_order(ModelAction *curr)
                                 * 3) If normal write, we need to look at earlier actions, so
                                 * continue processing list.
                                 */
+                               force_edge = true;
                                if (curr->is_rmw()) {
                                        if (curr->get_reads_from() != NULL)
                                                break;
@@ -954,7 +960,7 @@ bool ModelExecution::w_modification_order(ModelAction *curr)
                        /* C++, Section 29.3 statement 7 */
                        if (last_sc_fence_thread_before && act->is_write() &&
                                        *act < *last_sc_fence_thread_before) {
-                               added = mo_graph->addEdge(act, curr) || added;
+                               mo_graph->addEdge(act, curr, force_edge);
                                break;
                        }
 
@@ -970,10 +976,10 @@ bool ModelExecution::w_modification_order(ModelAction *curr)
                                 *   readfrom(act) --mo--> act
                                 */
                                if (act->is_write())
-                                       added = mo_graph->addEdge(act, curr) || added;
+                                       mo_graph->addEdge(act, curr, force_edge);
                                else if (act->is_read()) {
                                        //if previous read accessed a null, just keep going
-                                       added = mo_graph->addEdge(act->get_reads_from(), curr) || added;
+                                       mo_graph->addEdge(act->get_reads_from(), curr, force_edge);
                                }
                                break;
                        } else if (act->is_read() && !act->could_synchronize_with(curr) &&
@@ -994,8 +1000,6 @@ bool ModelExecution::w_modification_order(ModelAction *curr)
                        }
                }
        }
-
-       return added;
 }
 
 /**
@@ -1055,12 +1059,8 @@ bool ModelExecution::mo_may_allow(const ModelAction *writer, const ModelAction *
  * @return true, if the ModelExecution is certain that release_heads is complete;
  * false otherwise
  */
-bool ModelExecution::release_seq_heads(const ModelAction *rf,
-                                                                                                                                                        rel_heads_list_t *release_heads) const
+bool ModelExecution::release_seq_heads(const ModelAction *rf, rel_heads_list_t *release_heads) const
 {
-       /* Only check for release sequences if there are no cycles */
-       if (mo_graph->checkForCycles())
-               return false;
 
        for ( ;rf != NULL;rf = rf->get_reads_from()) {
                ASSERT(rf->is_write());
@@ -1327,7 +1327,7 @@ bool valequals(uint64_t val1, uint64_t val2, int size) {
  * @param curr is the current ModelAction that we are exploring; it must be a
  * 'read' operation.
  */
-ModelVector<ModelAction *> *  ModelExecution::build_may_read_from(ModelAction *curr)
+SnapVector<const ModelAction *> *  ModelExecution::build_may_read_from(ModelAction *curr)
 {
        SnapVector<action_list_t> *thrd_lists = obj_thrd_map.get(curr->get_location());
        unsigned int i;
@@ -1338,7 +1338,7 @@ ModelVector<ModelAction *> *  ModelExecution::build_may_read_from(ModelAction *c
        if (curr->is_seqcst())
                last_sc_write = get_last_seq_cst_write(curr);
 
-       ModelVector<ModelAction *> * rf_set = new ModelVector<ModelAction *>();
+       SnapVector<const ModelAction *> * rf_set = new SnapVector<const ModelAction *>();
 
        /* Iterate over all threads */
        for (i = 0;i < thrd_lists->size();i++) {
@@ -1346,10 +1346,21 @@ ModelVector<ModelAction *> *  ModelExecution::build_may_read_from(ModelAction *c
                action_list_t *list = &(*thrd_lists)[i];
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin();rit != list->rend();rit++) {
-                       ModelAction *act = *rit;
+                       const ModelAction *act = *rit;
 
                        /* Only consider 'write' actions */
-                       if (!act->is_write() || act == curr)
+                       if (!act->is_write()) {
+                               if (act != curr && act->is_read() && act->happens_before(curr)) {
+                                       const ModelAction *tmp = act->get_reads_from();
+                                       if (((unsigned int) id_to_int(tmp->get_tid()))==i)
+                                               act = tmp;
+                                       else
+                                               break;
+                               } else
+                                       continue;
+                       }
+
+                       if (act == curr)
                                continue;
 
                        /* Don't consider more than one seq_cst write if we are a seq_cst read. */
@@ -1373,8 +1384,8 @@ ModelVector<ModelAction *> *  ModelExecution::build_may_read_from(ModelAction *c
                        }
 
                        if (allow_read) {
-                         /* Only add feasible reads */
-                         rf_set->push_back(act);
+                               /* Only add feasible reads */
+                               rf_set->push_back(act);
                        }
 
                        /* Include at most one act per-thread that "happens before" curr */