Version that finds the bug of iris
[c11tester.git] / newfuzzer.cc
index 5675c7907152d53169ed83981405f1f2dc2a6e4c..e76d8961e47d3357360be5ee09270e4b0d75f01e 100644 (file)
@@ -4,7 +4,6 @@
 #include "history.h"
 #include "funcnode.h"
 #include "funcinst.h"
-#include "predicate.h"
 #include "concretepredicate.h"
 #include "waitobj.h"
 
@@ -19,7 +18,8 @@ NewFuzzer::NewFuzzer() :
        thrd_pruned_writes(),
        paused_thread_list(),
        paused_thread_table(128),
-       failed_predicates(32)
+       failed_predicates(32),
+       dist_info_vec()
 {}
 
 /**
@@ -33,7 +33,7 @@ void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *executio
 
 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);
@@ -48,9 +48,10 @@ 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);
-               Predicate * selected_branch = selectBranch(tid, curr_pred, read_inst);
-
                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 (!failed_predicates.isEmpty())
@@ -62,39 +63,25 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
 
        // No write satisfies the selected predicate, so pause this thread.
        while ( rf_set->size() == 0 ) {
-               Thread * read_thread = execution->get_thread(tid);
+               Predicate * selected_branch = get_selected_child_branch(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());
 
-               if (find_threads(read)) {
-                       // reset thread pending action and revert sequence numbers
-                       read_thread->set_pending(read);
-                       read->reset_seq_number();
-                       execution->restore_last_seq_num();
-
-                       conditional_sleep(read_thread);
-                       // Returning -1 stops the while loop of ModelExecution::process_read
-                       return -1;
-               } else {
-                       Predicate * selected_branch = get_selected_child_branch(tid);
-                       selected_branch->incr_fail_count();
-                       failed_predicates.put(selected_branch, true);
-
-                       SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
-                       for (uint i = 0; i < pruned_writes->size(); i++) {
-                               rf_set->push_back( (*pruned_writes)[i] );
-                       }
+               SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
+               for (uint i = 0; i < pruned_writes->size(); i++) {
+                       rf_set->push_back( (*pruned_writes)[i] );
+               }
 
-                       // Reselect a predicate and prune writes
-                       Predicate * curr_pred = selected_branch->get_parent();
-                       FuncInst * read_inst = thrd_last_func_inst[thread_id];
-                       selected_branch = selectBranch(tid, curr_pred, read_inst);
+               // Reselect a predicate and prune writes
+               Predicate * curr_pred = selected_branch->get_parent();
+               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);
+               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(selected_branch);
        }
 
        ASSERT(rf_set->size() != 0);
@@ -103,6 +90,48 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
        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)
+{
+       ASSERT(!rf_set->empty());
+       if (curr_pred == NULL || read_inst == NULL)
+               return;
+
+       ModelVector<Predicate *> * children = curr_pred->get_children();
+
+       /* Iterate over all predicate children */
+       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;
+
+                       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;
+                               }
+                       }
+               }
+
+       }
+}
+
+
 /* Select a random branch from the children of curr_pred 
  * @return The selected branch
  */
@@ -119,16 +148,11 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func
 
        ModelVector<Predicate *> * children = curr_pred->get_children();
        SnapVector<Predicate *> branches;
-       uint32_t numerator = 1;
 
        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;
                }
        }
 
@@ -138,14 +162,14 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func
                return NULL;
        }
 
-       // randomly select a branch
-       // int random_index = random() % branches.size();
-       // Predicate * random_branch = branches[ random_index ];
-
-       int index = choose_index(&branches, numerator);
+       int index = choose_index(&branches, 0);
        Predicate * random_branch = branches[ 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);
+
        return random_branch;
 }
 
@@ -167,6 +191,8 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func
  */
 int NewFuzzer::choose_index(SnapVector<Predicate *> * branches, uint32_t numerator)
 {
+       return random() % branches->size();
+/*--
        if (branches->size() == 1)
                return 0;
 
@@ -174,7 +200,7 @@ int NewFuzzer::choose_index(SnapVector<Predicate *> * branches, uint32_t numerat
        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() + 2 * branch->get_fail_count() + 1);
+               double factor = (double) numerator / (branch->get_expl_count() + 5 * branch->get_fail_count() + 1);
                total_factor += factor;
                factors.push_back(factor);
        }
@@ -192,6 +218,7 @@ int NewFuzzer::choose_index(SnapVector<Predicate *> * branches, uint32_t numerat
        }
 
        return index;
+*/
 }
 
 Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
@@ -235,42 +262,11 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
        while ( index < rf_set->size() ) {
                ModelAction * write_act = (*rf_set)[index];
                uint64_t write_val = write_act->get_write_value();
-               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:
-                                       return false;
-                               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;
-                       }
+               bool no_predicate = false;
+               bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &no_predicate);
 
-                       if (!satisfy_predicate)
-                               break;
-               }
+               if (no_predicate)
+                       return false;
 
                if (!satisfy_predicate) {
                        ASSERT(rf_set != NULL);
@@ -311,6 +307,28 @@ 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;
@@ -348,12 +366,14 @@ void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads)
        history->remove_waiting_write(tid);
        history->remove_waiting_thread(tid);
 
-       //model_print("thread %d is woken up\n", tid);
        threadlist[*numthreads] = tid;
        (*numthreads)++;
 
+/*--
        Predicate * selected_branch = get_selected_child_branch(tid);
-       selected_branch->incr_fail_count();
+       update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
+*/
+
        model_print("thread %d is woken up\n", tid);
 }
 
@@ -375,10 +395,17 @@ void NewFuzzer::notify_paused_thread(Thread * thread)
        history->remove_waiting_write(tid);
        history->remove_waiting_thread(tid);
 
+/*--
+       Predicate * selected_branch = get_selected_child_branch(tid);
+       update_predicate_score(selected_branch, SLEEP_SUCCESS);
+*/
+
        model_print("** thread %d is woken up\n", tid);
 }
 
-/* Find threads that may write values that the pending read action is waiting for
+/* Find threads that may write values that the pending read action is waiting for.
+ * Side effect: waiting thread related info are stored in dist_info_vec
+ *
  * @return True if any thread is found
  */
 bool NewFuzzer::find_threads(ModelAction * pending_read)
@@ -404,9 +431,10 @@ bool NewFuzzer::find_threads(ModelAction * pending_read)
 
                        int distance = node->compute_distance(target_node);
                        if (distance != -1) {
-                               history->add_waiting_thread(self_id, tid, target_node, distance);
                                finds_waiting_for = true;
                                //model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance);
+
+                               dist_info_vec.push_back(node_dist_info(tid, target_node, distance));
                        }
                }
        }
@@ -414,6 +442,88 @@ 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;