fix mutex_trylock bug
[c11tester.git] / newfuzzer.cc
index 9d061bbf9a857d41938bb7394d00d18e4bffed1b..7d4e8b1810880f600393e76f5618af8dc2b9516b 100644 (file)
 NewFuzzer::NewFuzzer() :
        thrd_last_read_act(),
        thrd_last_func_inst(),
+       available_branches_tmp_storage(),
        thrd_selected_child_branch(),
        thrd_pruned_writes(),
        paused_thread_list(),
        paused_thread_table(128),
-       failed_predicates(32),
        dist_info_vec()
 {}
 
 /**
  * @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);
@@ -48,56 +48,49 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                FuncNode * func_node = history->get_curr_func_node(tid);
                Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
                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, 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, rf_set)) {
+                                               selected_branch = selectBranch(tid, curr_pred, read_inst);
+                                               break;
+                                       }
+                               }
+
+                               delete it;
+                       }
 
-               if (!failed_predicates.isEmpty())
-                       failed_predicates.reset();
+                       thrd_selected_child_branch[thread_id] = selected_branch;
+                       prune_writes(tid, selected_branch, rf_set);
+               }
 
                thrd_last_read_act[thread_id] = read;
                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);
 
-               //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());
-
-/*--
-               Thread * read_thread = execution->get_thread(tid);
-               bool should_reselect_predicate = true;
-               bool should_sleep = should_conditional_sleep(selected_branch);
-               dist_info_vec.clear();
-
-               if (!find_threads(read)) {
-                       update_predicate_score(selected_branch, SLEEP_FAIL_TYPE1);
-                       should_reselect_predicate = true;
-               } else if (!should_sleep) {
-                       update_predicate_score(selected_branch, SLEEP_FAIL_TYPE2);
-                       should_reselect_predicate = true;
-               } else {
-                       for (uint i = 0; i < dist_info_vec.size(); i++) {
-                               struct node_dist_info info = dist_info_vec[i];
-                               history->add_waiting_thread(tid, info.tid, info.target, info.dist);
-                       }
-
-                       // reset thread pending action and revert sequence numbers
-                       read_thread->set_pending(read);
-                       read->reset_seq_number();
-                       execution->restore_last_seq_num();
+               // Increment failure count
+               selected_branch->incr_fail_count();
+               func_node->add_predicate_to_trace(tid, selected_branch);        // For updating predicate weight
 
-                       conditional_sleep(read_thread);
-                       // Returning -1 stops the while loop of ModelExecution::process_read
-                       return -1;      
-               }
-*/
+               //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());
 
                SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
-               for (uint i = 0; i < pruned_writes->size(); i++) {
+               for (uint i = 0;i < pruned_writes->size();i++) {
                        rf_set->push_back( (*pruned_writes)[i] );
                }
 
@@ -105,63 +98,49 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                Predicate * curr_pred = selected_branch->get_parent();
                FuncInst * read_inst = thrd_last_func_inst[thread_id];
                selected_branch = selectBranch(tid, curr_pred, read_inst);
+               thrd_selected_child_branch[thread_id] = selected_branch;
 
-               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);
+               prune_writes(tid, selected_branch, rf_set);
 
                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,
+                                                                                                                                       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++) {
+       for (uint i = 0;i < children->size();i++) {
                Predicate * branch = (*children)[i];
 
                /* 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 
+/* Select a random branch from the children of curr_pred
  * @return The selected branch
  */
 Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, FuncInst * read_inst)
@@ -175,84 +154,54 @@ 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);
-
-                       /*-- max of (exploration counts + 1)
-                       if (child->get_expl_count() + 1 > numerator)
-                               numerator = child->get_expl_count() + 1;
-                       */
-               }
-       }
-
        // 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 ];
-       thrd_selected_child_branch[thread_id] = random_branch;
+       int index = choose_branch_index(&available_branches_tmp_storage);
+       Predicate * selected_branch = available_branches_tmp_storage[ index ];
 
-       // 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;
+       return selected_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++) {
+       double total_weight = 0;
+       SnapVector<double> weights;
+       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 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 < factors.size(); i++) {
+       for (uint i = 0;i < weights.size();i++) {
                index = i;
-               prob_sum += (double) (factors[i] / total_factor);
+               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)
@@ -264,13 +213,12 @@ Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
        return thrd_selected_child_branch[thread_id];
 }
 
-/* Remove writes from the rf_set that do not satisfie the selected predicate, 
+/* Remove writes from the rf_set that do not satisfie the selected predicate,
  * and store them in thrd_pruned_writes
  *
  * @return true if rf_set is pruned
  */
-bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
-       SnapVector<ModelAction *> * rf_set, inst_act_map_t * inst_act_map)
+bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, SnapVector<ModelAction *> * rf_set)
 {
        if (pred == NULL)
                return false;
@@ -284,83 +232,105 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
        if (thrd_pruned_writes.size() <= (uint) thread_id) {
                uint new_size = thread_id + 1;
                thrd_pruned_writes.resize(new_size);
-               for (uint i = old_size; i < new_size; i++)
+               for (uint i = old_size;i < new_size;i++)
                        thrd_pruned_writes[i] = new SnapVector<ModelAction *>();
        }
        SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
        pruned_writes->clear(); // clear the old pruned_writes set
 
        bool pruned = false;
-       uint index = 0;
+       uint rf_index = 0;
 
-       while ( index < rf_set->size() ) {
-               ModelAction * write_act = (*rf_set)[index];
+       while ( rf_index < rf_set->size() ) {
+               ModelAction * write_act = (*rf_set)[rf_index];
                uint64_t write_val = write_act->get_write_value();
                bool no_predicate = false;
-               bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &no_predicate);
+               bool satisfy_predicate = true;
+
+               // Check if the write value satisfies the predicates
+               PredExprSetIter * pred_expr_it = pred_expressions->iterator();
+               while (pred_expr_it->hasNext()) {
+                       struct pred_expr * expression = pred_expr_it->next();
+                       bool equality;
+
+                       switch (expression->token) {
+                       case NOPREDICATE:
+                               no_predicate = true;
+                               break;
+                       case EQUALITY:
+                               FuncInst * to_be_compared;
+                               FuncNode * func_node;
+                               uint64_t last_read;
+
+                               to_be_compared = expression->func_inst;
+                               func_node = history->get_curr_func_node(tid);
+                               last_read = func_node->get_associated_read(tid, to_be_compared);
+                               ASSERT(last_read != VALUE_NONE);
+
+                               equality = (write_val == last_read);
+                               if (equality != expression->value)
+                                       satisfy_predicate = false;
+                               break;
+                       case NULLITY:
+                               // TODO: implement likely to be null
+                               equality = ((void*) (write_val & 0xffffffff) == NULL);
+                               if (equality != expression->value)
+                                       satisfy_predicate = false;
+                               break;
+                       default:
+                               model_print("unknown predicate token\n");
+                               break;
+                       }
+
+                       if (!satisfy_predicate)
+                               break;
+               }
+               delete pred_expr_it;
 
                if (no_predicate)
                        return false;
 
                if (!satisfy_predicate) {
                        ASSERT(rf_set != NULL);
-                       (*rf_set)[index] = rf_set->back();
+                       (*rf_set)[rf_index] = rf_set->back();
                        rf_set->pop_back();
                        pruned_writes->push_back(write_act);
                        pruned = true;
                } else
-                       index++;
+                       rf_index++;
        }
 
        return pruned;
 }
 
-/* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate. 
+/* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate.
  *
  * @param thread A thread whose last action is a read
  */
 void NewFuzzer::conditional_sleep(Thread * thread)
 {
-       int index = paused_thread_list.size();
+/*
+        int index = paused_thread_list.size();
 
-       model->getScheduler()->add_sleep(thread);
-       paused_thread_list.push_back(thread);
-       paused_thread_table.put(thread, index); // Update table
-
-       /* Add the waiting condition to ModelHistory */
-       ModelAction * read = thread->get_pending();
-       thread_id_t tid = thread->get_id();
-       FuncNode * func_node = history->get_curr_func_node(tid);
-       inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
+        model->getScheduler()->add_sleep(thread);
+        paused_thread_list.push_back(thread);
+        paused_thread_table.put(thread, index);        // Update table
 
-       Predicate * selected_branch = get_selected_child_branch(tid);
-       ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
-       concrete->set_location(read->get_location());
+        // Add the waiting condition to ModelHistory
+        ModelAction * read = thread->get_pending();
+        thread_id_t tid = thread->get_id();
+        FuncNode * func_node = history->get_curr_func_node(tid);
+   //  inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
 
-       history->add_waiting_write(concrete);
-       /* 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;
+        Predicate * selected_branch = get_selected_child_branch(tid);
+   //  ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
+        concrete->set_location(read->get_location());
 
-       // should sleep if random_num falls within [0, sleep_score)
-       if (random_num < sleep_score)
-               return true;
+        ASSERT(false);
 
-       return false;
-       */
+   //  history->add_waiting_write(concrete);
+        // history->add_waiting_thread is already called in find_threads
+ */
 }
 
 bool NewFuzzer::has_paused_threads()
@@ -374,7 +344,6 @@ Thread * NewFuzzer::selectThread(int * threadlist, int numthreads)
                wake_up_paused_threads(threadlist, &numthreads);
                //model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]);
        }
-
        int random_index = random() % numthreads;
        int thread = threadlist[random_index];
        thread_id_t curr_tid = int_to_id(thread);
@@ -404,9 +373,9 @@ void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads)
        (*numthreads)++;
 
 /*--
-       Predicate * selected_branch = get_selected_child_branch(tid);
-       update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
-*/
+        Predicate * selected_branch = get_selected_child_branch(tid);
+        update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
+ */
 
        model_print("thread %d is woken up\n", tid);
 }
@@ -430,9 +399,9 @@ void NewFuzzer::notify_paused_thread(Thread * thread)
        history->remove_waiting_thread(tid);
 
 /*--
-       Predicate * selected_branch = get_selected_child_branch(tid);
-       update_predicate_score(selected_branch, SLEEP_SUCCESS);
-*/
+        Predicate * selected_branch = get_selected_child_branch(tid);
+        update_predicate_score(selected_branch, SLEEP_SUCCESS);
+ */
 
        model_print("** thread %d is woken up\n", tid);
 }
@@ -451,9 +420,9 @@ bool NewFuzzer::find_threads(ModelAction * pending_read)
        bool finds_waiting_for = false;
 
        SnapVector<FuncNode *> * func_node_list = history->getWrFuncNodes(location);
-       for (uint i = 0; i < func_node_list->size(); i++) {
+       for (uint i = 0;i < func_node_list->size();i++) {
                FuncNode * target_node = (*func_node_list)[i];
-               for (uint i = 1; i < execution->get_num_threads(); i++) {
+               for (uint i = 1;i < execution->get_num_threads();i++) {
                        thread_id_t tid = int_to_id(i);
                        if (tid == self_id)
                                continue;
@@ -476,89 +445,7 @@ 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)
-{
-       bool satisfy_predicate = true;
-
-       PredExprSetIter * pred_expr_it = pred_expressions->iterator();
-       while (pred_expr_it->hasNext()) {
-               struct pred_expr * expression = pred_expr_it->next();
-               bool equality;
-
-               switch (expression->token) {
-                       case NOPREDICATE:
-                               *no_predicate = true;
-                               break;
-                       case EQUALITY:
-                               FuncInst * to_be_compared;
-                               ModelAction * last_act;
-                               uint64_t last_read;
-
-                               to_be_compared = expression->func_inst;
-                               last_act = inst_act_map->get(to_be_compared);
-                               last_read = last_act->get_reads_from_value();
-
-                               equality = (write_val == last_read);
-                               if (equality != expression->value)
-                                       satisfy_predicate = false;
-                               break;
-                       case NULLITY:
-                               equality = ((void*)write_val == NULL);
-                               if (equality != expression->value)
-                                       satisfy_predicate = false;
-                               break;
-                       default:
-                               model_print("unknown predicate token\n");
-                               break;
-               }
-
-               if (!satisfy_predicate)
-                       break;
-       }
-
-       return satisfy_predicate;
-}
-
 bool NewFuzzer::shouldWait(const ModelAction * act)
 {
-       return random() & 1;
+       return true;
 }