Compute the threads that a paused thread my wait for
[c11tester.git] / newfuzzer.cc
index 68efd37d437a47d4a6ad064f90d67d4f0f181719..b0874c85b5c2b2714a1bacd1d5f7194053953846 100644 (file)
@@ -1,17 +1,23 @@
 #include "newfuzzer.h"
 #include "threads-model.h"
-#include "model.h"
 #include "action.h"
-#include "execution.h"
+#include "history.h"
 #include "funcnode.h"
+#include "funcinst.h"
+#include "predicate.h"
+#include "concretepredicate.h"
+
+#include "model.h"
 #include "schedule.h"
+#include "execution.h"
 
 NewFuzzer::NewFuzzer() :
        thrd_last_read_act(),
        thrd_curr_pred(),
        thrd_selected_child_branch(),
        thrd_pruned_writes(),
-       paused_thread_set()
+       paused_thread_set(),
+       paused_thread_table(128)
 {}
 
 /**
@@ -25,6 +31,8 @@ void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *executio
 
 int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set)
 {
+//     return random() % rf_set->size();
+
        thread_id_t tid = read->get_tid();
        int thread_id = id_to_int(tid);
 
@@ -35,28 +43,29 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
        if (read != thrd_last_read_act[thread_id]) {
                thrd_last_read_act[thread_id] = read;
 
-               SnapVector<func_id_list_t> * thrd_func_list = execution->get_thrd_func_list();
-               uint32_t func_id = (*thrd_func_list)[thread_id].back();
-               FuncNode * func_node = history->get_func_node(func_id);
-               inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
+               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);
                prune_writes(tid, selected_branch, rf_set, inst_act_map);
        }
 
-       // TODO: make this thread sleep if no write satisfies the chosen predicate
-       // if no read satisfies the selected predicate
+       // No write satisfies the selected predicate, so pause this thread.
        if ( rf_set->size() == 0 ) {
                Thread * read_thread = execution->get_thread(tid);
-               model_print("the %d read action of thread %d is unsuccessful\n", read->get_seq_number(), read_thread->get_id());
+               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());
 
+               // reset thread pending action and revert sequence numbers
                read_thread->set_pending(read);
-               read->reset_seq_number();       // revert some operations
+               read->reset_seq_number();
                execution->restore_last_seq_num();
-               
+
                conditional_sleep(read_thread);
+
+               find_threads(read);
+
                return -1;
 /*
                SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
@@ -146,39 +155,32 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
 
        bool pruned = false;
        uint index = 0;
+
+       ConcretePredicate * concrete_pred = pred->evaluate(inst_act_map, tid);
+       SnapVector<struct concrete_pred_expr> * concrete_exprs = concrete_pred->getExpressions();
+
        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();
-                       uint64_t write_val = write_act->get_write_value();
+               for (uint i = 0; i < concrete_exprs->size(); i++) {
+                       struct concrete_pred_expr concrete = (*concrete_exprs)[i];
                        bool equality;
 
-                       // No predicate, return false
-                       if (expression->token == NOPREDICATE)
-                               return pruned;
-
-                       switch(expression->token) {
+                       switch (concrete.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)
+                                       equality = (write_val == concrete.value);
+                                       if (equality != concrete.equality)
                                                satisfy_predicate = false;
                                        break;
                                case NULLITY:
                                        equality = ((void*)write_val == NULL);
-                                       if (equality != expression->value)
-                                               satisfy_predicate = false;
-                                       break;
+                                        if (equality != concrete.equality)
+                                                satisfy_predicate = false;
+                                        break;
                                default:
                                        model_print("unknown predicate token\n");
                                        break;
@@ -198,6 +200,8 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
                        index++;
        }
 
+       delete concrete_pred;
+
        return pruned;
 }
 
@@ -207,8 +211,23 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
  */
 void NewFuzzer::conditional_sleep(Thread * thread)
 {
+       int index = paused_thread_set.size();
+
        model->getScheduler()->add_sleep(thread);
        paused_thread_set.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);
+
+       Predicate * selected_branch = get_selected_child_branch(tid);
+       ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
+       concrete->set_location(read->get_location());
+
+       history->add_waiting_write(concrete);
 }
 
 bool NewFuzzer::has_paused_threads()
@@ -220,8 +239,7 @@ Thread * NewFuzzer::selectThread(int * threadlist, int numthreads)
 {
        if (numthreads == 0 && has_paused_threads()) {
                wake_up_paused_threads(threadlist, &numthreads);
-               model_print("list size: %d\n", numthreads);
-               model_print("active t id: %d\n", threadlist[0]);
+               model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]);
        }
 
        int random_index = random() % numthreads;
@@ -230,16 +248,74 @@ Thread * NewFuzzer::selectThread(int * threadlist, int numthreads)
        return model->get_thread(curr_tid);
 }
 
+/* Force waking up one of threads paused by Fuzzer, because otherwise
+ * the Fuzzer is not making progress
+ */
 void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads)
 {
        int random_index = random() % paused_thread_set.size();
        Thread * thread = paused_thread_set[random_index];
        model->getScheduler()->remove_sleep(thread);
 
-       paused_thread_set[random_index] = paused_thread_set.back();
+       Thread * last_thread = paused_thread_set.back();
+       paused_thread_set[random_index] = last_thread;
        paused_thread_set.pop_back();
+       paused_thread_table.put(last_thread, random_index);     // Update table
+       paused_thread_table.remove(thread);
+
+       thread_id_t tid = thread->get_id();
+       history->remove_waiting_write(tid);
 
-       model_print("thread %d is woken up\n", thread->get_id());
-       threadlist[*numthreads] = thread->get_id();
+       model_print("thread %d is woken up\n", tid);
+       threadlist[*numthreads] = tid;
        (*numthreads)++;
 }
+
+/* Wake up conditional sleeping threads if the desired write is available */
+void NewFuzzer::notify_paused_thread(Thread * thread)
+{
+       ASSERT(paused_thread_table.contains(thread));
+
+       int index = paused_thread_table.get(thread);
+       model->getScheduler()->remove_sleep(thread);
+
+       Thread * last_thread = paused_thread_set.back();
+       paused_thread_set[index] = last_thread;
+       paused_thread_set.pop_back();
+       paused_thread_table.put(last_thread, index);    // Update table
+       paused_thread_table.remove(thread);
+
+       thread_id_t tid = thread->get_id();
+       history->remove_waiting_write(tid);
+}
+
+/* Find threads that may write values that the pending read action is waiting for */
+void NewFuzzer::find_threads(ModelAction * pending_read)
+{
+       void * location = pending_read->get_location();
+       thread_id_t self_id = pending_read->get_tid();
+
+       SnapVector<FuncNode *> * func_node_list = history->getWrFuncNodes(location);
+       for (uint i = 0; i < func_node_list->size(); i++) {
+               FuncNode * target_node = (*func_node_list)[i];
+               model_print("node %s may write to loc %p\n", target_node->get_func_name(), location);
+
+               for (uint i = 1; i < execution->get_num_threads(); i++) {
+                       thread_id_t tid = int_to_id(i);
+                       if (tid == self_id)
+                               continue;
+
+                       FuncNode * node = history->get_curr_func_node(tid);
+                       if (node == NULL)
+                               continue;
+
+                       int distance = node->compute_distance(target_node);
+                       model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance);
+               }
+       }
+}
+
+bool NewFuzzer::shouldWait(const ModelAction * act)
+{
+       return random() & 1;
+}