Bug fix
[c11tester.git] / newfuzzer.cc
index c7d70ac6487982ebd502c8f57b8b2523a5beb133..027b7d4fec9c13858ada1dcc96882396eb62e98e 100644 (file)
@@ -14,6 +14,7 @@
 NewFuzzer::NewFuzzer() :
        thrd_last_read_act(),
        thrd_last_func_inst(),
+       available_branches_tmp_storage(),
        thrd_selected_child_branch(),
        thrd_pruned_writes(),
        paused_thread_list(),
@@ -25,15 +26,15 @@ NewFuzzer::NewFuzzer() :
 /**
  * @brief Register the ModelHistory and ModelExecution engine
  */
-void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *execution)
+void NewFuzzer::register_engine(ModelChecker *_model, ModelExecution *execution)
 {
-       this->history = history;
+       this->history = _model->get_history();
        this->execution = execution;
 }
 
 int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set)
 {
-       return random() % rf_set->size();
+//     return random() % rf_set->size();
 
        thread_id_t tid = read->get_tid();
        int thread_id = id_to_int(tid);
@@ -50,9 +51,29 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                FuncInst * read_inst = func_node->get_inst(read);
                inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
 
-               check_store_visibility(curr_pred, read_inst, inst_act_map, rf_set);
-               Predicate * selected_branch = selectBranch(tid, curr_pred, read_inst);
-               prune_writes(tid, selected_branch, rf_set, inst_act_map);
+               if (curr_pred != NULL)  {
+                       Predicate * selected_branch = NULL;
+
+                       if (check_branch_inst(curr_pred, read_inst, inst_act_map, rf_set))
+                               selected_branch = selectBranch(tid, curr_pred, read_inst);
+                       else {
+                               // no child of curr_pred matches read_inst, check back edges
+                               PredSet * back_edges = curr_pred->get_backedges();
+                               PredSetIter * it = back_edges->iterator();
+
+                               while (it->hasNext()) {
+                                       curr_pred = it->next();
+                                       if (check_branch_inst(curr_pred, read_inst, inst_act_map, rf_set)) {
+                                               selected_branch = selectBranch(tid, curr_pred, read_inst);
+                                               break;
+                                       }
+                               }
+
+                               delete it;
+                       }
+
+                       prune_writes(tid, selected_branch, rf_set, inst_act_map);
+               }
 
                if (!failed_predicates.isEmpty())
                        failed_predicates.reset();
@@ -61,9 +82,15 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                thrd_last_func_inst[thread_id] = read_inst;
        }
 
-       // No write satisfies the selected predicate, so pause this thread.
+       // The chosen branch fails, reselect new branches
        while ( rf_set->size() == 0 ) {
                Predicate * selected_branch = get_selected_child_branch(tid);
+               FuncNode * func_node = history->get_curr_func_node(tid);
+
+               // Add failed predicate to NewFuzzer and FuncNode
+               failed_predicates.put(selected_branch, true);
+               func_node->add_failed_predicate(selected_branch);
+               selected_branch->incr_fail_count();
 
                //model_print("the %d read action of thread %d at %p is unsuccessful\n", read->get_seq_number(), read_thread->get_id(), read->get_location());
 
@@ -77,27 +104,31 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                FuncInst * read_inst = thrd_last_func_inst[thread_id];
                selected_branch = selectBranch(tid, curr_pred, read_inst);
 
-               FuncNode * func_node = history->get_curr_func_node(tid);
                inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
                prune_writes(tid, selected_branch, rf_set, inst_act_map);
 
                ASSERT(selected_branch);
        }
 
-       ASSERT(rf_set->size() != 0);
        int random_index = random() % rf_set->size();
 
        return random_index;
 }
 
-void NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_inst,
-                                                                                                                                                        inst_act_map_t * inst_act_map, SnapVector<ModelAction *> * rf_set)
+/* Check if children of curr_pred match read_inst.
+ * @return False if no child matches read_inst
+ */
+bool NewFuzzer::check_branch_inst(Predicate * curr_pred, FuncInst * read_inst,
+                                                                                                                                       inst_act_map_t * inst_act_map, SnapVector<ModelAction *> * rf_set)
 {
+       available_branches_tmp_storage.clear();
+
        ASSERT(!rf_set->empty());
        if (curr_pred == NULL || read_inst == NULL)
-               return;
+               return false;
 
        ModelVector<Predicate *> * children = curr_pred->get_children();
+       bool any_child_match = false;
 
        /* Iterate over all predicate children */
        for (uint i = 0;i < children->size();i++) {
@@ -105,32 +136,14 @@ void NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_in
 
                /* The children predicates may have different FuncInsts */
                if (branch->get_func_inst() == read_inst) {
-                       PredExprSet * pred_expressions = branch->get_pred_expressions();
-
-                       /* Do not check unset predicates */
-                       if (pred_expressions->isEmpty())
-                               continue;
-
+                       any_child_match = true;
                        branch->incr_total_checking_count();
-
-                       /* Iterate over all write actions */
-                       for (uint j = 0;j < rf_set->size();j++) {
-                               ModelAction * write_act = (*rf_set)[j];
-                               uint64_t write_val = write_act->get_write_value();
-                               bool dummy = true;
-                               bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &dummy);
-
-                               /* If one write value satisfies the predicate, go to check the next predicate */
-                               if (satisfy_predicate) {
-                                       branch->incr_store_visible_count();
-                                       break;
-                               }
-                       }
+                       available_branches_tmp_storage.push_back(branch);
                }
-
        }
-}
 
+       return any_child_match;
+}
 
 /* Select a random branch from the children of curr_pred
  * @return The selected branch
@@ -146,79 +159,55 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func
                return NULL;
        }
 
-       ModelVector<Predicate *> * children = curr_pred->get_children();
-       SnapVector<Predicate *> branches;
-
-       for (uint i = 0;i < children->size();i++) {
-               Predicate * child = (*children)[i];
-               if (child->get_func_inst() == read_inst && !failed_predicates.contains(child)) {
-                       branches.push_back(child);
-               }
-       }
-
        // predicate children have not been generated
-       if (branches.size() == 0) {
+       if (available_branches_tmp_storage.size() == 0) {
                thrd_selected_child_branch[thread_id] = NULL;
                return NULL;
        }
 
-       int index = choose_index(&branches, 0);
-       Predicate * random_branch = branches[ index ];
+       int index = choose_branch_index(&available_branches_tmp_storage);
+       Predicate * random_branch = available_branches_tmp_storage[ index ];
        thrd_selected_child_branch[thread_id] = random_branch;
 
-       // Update predicate tree position
-       FuncNode * func_node = history->get_curr_func_node(tid);
-       func_node->set_predicate_tree_position(tid, random_branch);
+       /* Remove the chosen branch from vec in case that this
+        * branch fails and need to choose another one */
+       available_branches_tmp_storage[index] = available_branches_tmp_storage.back();
+       available_branches_tmp_storage.pop_back();
 
        return random_branch;
 }
 
 /**
- * @brief Select a branch from the given predicate branches based
- * on their exploration counts.
- *
- * Let b_1, ..., b_n be branches with exploration counts c_1, ..., c_n
- * M := max(c_1, ..., c_n) + 1
- * Factor f_i := M / (c_i + 1)
- * The probability p_i that branch b_i is selected:
- *     p_i := f_i / (f_1 + ... + f_n)
- *          = \fraction{ 1/(c_i + 1) }{ 1/(c_1 + 1) + ... + 1/(c_n + 1) }
- *
- * Note: (1) c_i + 1 is used because counts may be 0.
- *      (2) The numerator of f_i is chosen to reduce the effect of underflow
- *
- * @param numerator is M defined above
+ * @brief Select a branch from the given predicate branch
  */
-int NewFuzzer::choose_index(SnapVector<Predicate *> * branches, uint32_t numerator)
+int NewFuzzer::choose_branch_index(SnapVector<Predicate *> * branches)
 {
-       return random() % branches->size();
-/*--
-        if (branches->size() == 1)
-                return 0;
-
-        double total_factor = 0;
-        SnapVector<double> factors = SnapVector<double>( branches->size() + 1 );
-        for (uint i = 0; i < branches->size(); i++) {
-                Predicate * branch = (*branches)[i];
-                double factor = (double) numerator / (branch->get_expl_count() + 5 * branch->get_fail_count() + 1);
-                total_factor += factor;
-                factors.push_back(factor);
-        }
-
-        double prob = (double) random() / RAND_MAX;
-        double prob_sum = 0;
-        int index = 0;
-
-        for (uint i = 0; i < factors.size(); i++) {
-                index = i;
-                prob_sum += (double) (factors[i] / total_factor);
-                if (prob_sum > prob) {
-                        break;
-                }
-        }
-
-        return index;
- */
+       if (branches->size() == 1)
+               return 0;
+
+       double total_weight = 0;
+       SnapVector<double> weights;
+       for (uint i = 0;i < branches->size();i++) {
+               Predicate * branch = (*branches)[i];
+               double weight = branch->get_weight();
+               total_weight += weight;
+               weights.push_back(weight);
+       }
+
+       double prob = (double) random() / RAND_MAX;
+       double prob_sum = 0;
+       int index = 0;
+
+       for (uint i = 0;i < weights.size();i++) {
+               index = i;
+               prob_sum += (double) (weights[i] / total_weight);
+               if (prob_sum > prob) {
+                       break;
+               }
+       }
+
+       return index;
+//     return random() % branches->size();
 }
 
 Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
@@ -307,28 +296,6 @@ void NewFuzzer::conditional_sleep(Thread * thread)
        /* history->add_waiting_thread is already called in find_threads */
 }
 
-/**
- * Decides whether a thread should condition sleep based on
- * the sleep score of the chosen predicate.
- *
- * sleep_score = 0: never sleeps
- * sleep_score = 100: always sleeps
- **/
-bool NewFuzzer::should_conditional_sleep(Predicate * predicate)
-{
-       return false;
-       /*
-          int sleep_score = predicate->get_sleep_score();
-          int random_num = random() % 100;
-
-          // should sleep if random_num falls within [0, sleep_score)
-          if (random_num < sleep_score)
-               return true;
-
-          return false;
-        */
-}
-
 bool NewFuzzer::has_paused_threads()
 {
        return paused_thread_list.size() != 0;
@@ -442,44 +409,6 @@ bool NewFuzzer::find_threads(ModelAction * pending_read)
        return finds_waiting_for;
 }
 
-/* Update predicate counts and scores (asynchronous) when the read value is not available
- *
- * @param type
- *        type 1: find_threads return false
- *        type 2: find_threads return true, but the fuzzer decides that that thread shall not sleep based on sleep score
- *        type 3: threads are put to sleep but woken up before the waited value appears
- *        type 4: threads are put to sleep and the waited vaule appears (success)
- */
-
-/*--
-   void NewFuzzer::update_predicate_score(Predicate * predicate, sleep_result_t type)
-   {
-        switch (type) {
-                case SLEEP_FAIL_TYPE1:
-                        predicate->incr_fail_count();
-
-                        // Do not choose this predicate when reselecting a new branch
-                        failed_predicates.put(predicate, true);
-                        break;
-                case SLEEP_FAIL_TYPE2:
-                        predicate->incr_fail_count();
-                        predicate->incr_sleep_score(1);
-                        failed_predicates.put(predicate, true);
-                        break;
-                case SLEEP_FAIL_TYPE3:
-                        predicate->incr_fail_count();
-                        predicate->decr_sleep_score(10);
-                        break;
-                case SLEEP_SUCCESS:
-                        predicate->incr_sleep_score(10);
-                        break;
-                default:
-                        model_print("unknown predicate result type.\n");
-                        break;
-        }
-   }
- */
-
 bool NewFuzzer::check_predicate_expressions(PredExprSet * pred_expressions,
                                                                                                                                                                                inst_act_map_t * inst_act_map, uint64_t write_val, bool * no_predicate)
 {
@@ -508,7 +437,8 @@ bool NewFuzzer::check_predicate_expressions(PredExprSet * pred_expressions,
                                satisfy_predicate = false;
                        break;
                case NULLITY:
-                       equality = ((void*)write_val == NULL);
+                       // TODO: implement likely to be null
+                       equality = ((void*) (write_val & 0xffffffff) == NULL);
                        if (equality != expression->value)
                                satisfy_predicate = false;
                        break;
@@ -521,6 +451,7 @@ bool NewFuzzer::check_predicate_expressions(PredExprSet * pred_expressions,
                        break;
        }
 
+       delete pred_expr_it;
        return satisfy_predicate;
 }