Performance fix; delete unused data structures
[c11tester.git] / history.cc
index 8682da317c56b63d8535ea4bca9ffc164143bc25..4fde914419161b3697561d5f71936065c40017f8 100644 (file)
@@ -19,7 +19,7 @@ ModelHistory::ModelHistory() :
        func_nodes()
 {
        /* The following are snapshot data structures */
-       write_history = new HashTable<void *, value_set_t *, uintptr_t, 4>();
+       write_history = new HashTable<void *, value_set_t *, uintptr_t, 0>();
        loc_rd_func_nodes_map = new HashTable<void *, SnapVector<FuncNode *> *, uintptr_t, 0>();
        loc_wr_func_nodes_map = new HashTable<void *, SnapVector<FuncNode *> *, uintptr_t, 0>();
        loc_waiting_writes_map = new HashTable<void *, SnapVector<ConcretePredicate *> *, uintptr_t, 0>();
@@ -28,11 +28,19 @@ ModelHistory::ModelHistory() :
        func_inst_act_maps = new HashTable<uint32_t, SnapVector<inst_act_map_t *> *, int, 0>(128);
 }
 
+ModelHistory::~ModelHistory()
+{
+       // TODO: complete deconstructor; maybe not needed
+       for (uint i = 0; i < thrd_wait_obj->size(); i++)
+               delete (*thrd_wait_obj)[i];
+}
+
 void ModelHistory::enter_function(const uint32_t func_id, thread_id_t tid)
 {
        //model_print("thread %d entering func %d\n", tid, func_id);
        ModelExecution * execution = model->get_execution();
        uint id = id_to_int(tid);
+
        SnapVector<func_id_list_t> * thrd_func_list = execution->get_thrd_func_list();
        SnapVector< SnapList<action_list_t *> *> *
                thrd_func_act_lists = execution->get_thrd_func_act_lists();
@@ -72,6 +80,9 @@ void ModelHistory::enter_function(const uint32_t func_id, thread_id_t tid)
                FuncNode * last_func_node = func_nodes[last_entered_func_id];
                last_func_node->add_out_edge(func_node);
        }
+
+       /* Monitor the statuses of threads waiting for tid */
+       monitor_waiting_thread(func_id, tid);
 }
 
 /* @param func_id a non-zero value */
@@ -137,26 +148,26 @@ void ModelHistory::resize_func_nodes(uint32_t new_size)
 void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
 {
        ModelExecution * execution = model->get_execution();
-       /* Return if thread i has not entered any function or has exited
-          from all functions */
        SnapVector<func_id_list_t> * thrd_func_list = execution->get_thrd_func_list();
        SnapVector< SnapList<action_list_t *> *> *
                thrd_func_act_lists = execution->get_thrd_func_act_lists();
 
-       uint32_t id = id_to_int(tid);
-       if ( thrd_func_list->size() <= id )
+       uint32_t thread_id = id_to_int(tid);
+       /* Return if thread tid has not entered any function that contains atomics */
+       if ( thrd_func_list->size() <= thread_id )
                return;
 
-       /* Get the function id that thread i is currently in */
-       uint32_t func_id = (*thrd_func_list)[id].back();
-       SnapList<action_list_t *> * func_act_lists = (*thrd_func_act_lists)[id];
+       /* Monitor the statuses of threads waiting for tid */
+       monitor_waiting_thread_counter(tid);
 
+       /* Every write action should be processed, including
+        * nonatomic writes (which have no position) */
        if (act->is_write()) {
                void * location = act->get_location();
                uint64_t value = act->get_write_value();
                update_write_history(location, value);
 
-               /* Update FuncNodes that may read from this location */
+               /* Notify FuncNodes that may read from this location */
                SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
                for (uint i = 0; i < func_node_list->size(); i++) {
                        FuncNode * func_node = (*func_node_list)[i];
@@ -166,20 +177,25 @@ void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
                check_waiting_write(act);
        }
 
-       /* The following does not care about actions without a position */
+       uint32_t func_id = (*thrd_func_list)[thread_id].back();
+
+       /* The following does not care about actions that are not inside
+        * any function that contains atomics or actions without a position */
        if (func_id == 0 || act->get_position() == NULL)
                return;
 
+       SnapList<action_list_t *> * func_act_lists = (*thrd_func_act_lists)[thread_id];
+
+       /* The list of actions that thread tid has taken in its current function */
        action_list_t * curr_act_list = func_act_lists->back();
-       ASSERT(curr_act_list != NULL);
 
        if (skip_action(act, curr_act_list))
                return;
 
-       FuncNode * func_node = func_nodes[func_id];
-
        /* Add to curr_inst_list */
        curr_act_list->push_back(act);
+
+       FuncNode * func_node = func_nodes[func_id];
        func_node->add_inst(act);
 
        if (act->is_read()) {
@@ -314,7 +330,6 @@ void ModelHistory::check_waiting_write(ModelAction * write_act)
        void * location = write_act->get_location();
        uint64_t value = write_act->get_write_value();
        SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
-       SnapVector<ConcretePredicate *> to_remove = SnapVector<ConcretePredicate *>();
        if (concrete_preds == NULL)
                return;
 
@@ -346,22 +361,16 @@ void ModelHistory::check_waiting_write(ModelAction * write_act)
                }
 
                if (satisfy_predicate) {
-                       to_remove.push_back(concrete_pred);
+                       /* Wake up threads */
+                       thread_id_t tid = concrete_pred->get_tid();
+                       Thread * thread = model->get_thread(tid);
+
+                       //model_print("** thread %d is woken up\n", thread->get_id());
+                       model->get_execution()->getFuzzer()->notify_paused_thread(thread);
                }
 
                index++;
        }
-
-       for (uint i = 0; i < to_remove.size(); i++) {
-               ConcretePredicate * concrete_pred = to_remove[i];
-
-               /* Wake up threads */
-               thread_id_t tid = concrete_pred->get_tid();
-               Thread * thread = model->get_thread(tid);
-
-               model_print("** thread %d is woken up\n", thread->get_id());
-               model->get_execution()->getFuzzer()->notify_paused_thread(thread);
-       }
 }
 
 WaitObj * ModelHistory::getWaitObj(thread_id_t tid)
@@ -378,6 +387,57 @@ WaitObj * ModelHistory::getWaitObj(thread_id_t tid)
        return (*thrd_wait_obj)[thread_id];
 }
 
+void ModelHistory::add_waiting_thread(thread_id_t self_id,
+       thread_id_t waiting_for_id, FuncNode * target_node, int dist)
+{
+       WaitObj * self_wait_obj = getWaitObj(self_id);
+       self_wait_obj->add_waiting_for(waiting_for_id, target_node, dist);
+
+       /* Update waited-by relation */
+       WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
+       other_wait_obj->add_waited_by(self_id);
+}
+
+/* Thread tid is woken up (or notified), so it is not waiting for others anymore */
+void ModelHistory::remove_waiting_thread(thread_id_t tid)
+{
+       WaitObj * self_wait_obj = getWaitObj(tid);
+       thrd_id_set_t * waiting_for = self_wait_obj->getWaitingFor();
+
+       /* Remove tid from waited_by's */
+       thrd_id_set_iter * iter = waiting_for->iterator();
+       while (iter->hasNext()) {
+               thread_id_t other_id = iter->next();
+               WaitObj * other_wait_obj = getWaitObj(other_id);
+               other_wait_obj->remove_waited_by(tid);
+       }
+
+       self_wait_obj->clear_waiting_for();
+}
+
+void ModelHistory::stop_waiting_for_node(thread_id_t self_id,
+       thread_id_t waiting_for_id, FuncNode * target_node)
+{
+       WaitObj * self_wait_obj = getWaitObj(self_id);
+       bool thread_removed = self_wait_obj->remove_waiting_for_node(waiting_for_id, target_node);
+
+       // model_print("\t%d gives up %d on node %d\n", self_id, waiting_for_id, target_node->get_func_id());
+
+       /* If thread self_id is not waiting for waiting_for_id anymore */
+       if (thread_removed) {
+               WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
+               other_wait_obj->remove_waited_by(self_id);
+
+               thrd_id_set_t * self_waiting_for = self_wait_obj->getWaitingFor();
+               if ( self_waiting_for->isEmpty() ) {
+                       // model_print("\tthread %d waits for nobody, wake up\n", self_id);
+                       ModelExecution * execution = model->get_execution();
+                       Thread * thread = execution->get_thread(self_id);
+                       execution->getFuzzer()->notify_paused_thread(thread);
+               }
+       }
+}
+
 SnapVector<inst_act_map_t *> * ModelHistory::getThrdInstActMap(uint32_t func_id)
 {
        ASSERT(func_id != 0);
@@ -393,6 +453,8 @@ SnapVector<inst_act_map_t *> * ModelHistory::getThrdInstActMap(uint32_t func_id)
 
 bool ModelHistory::skip_action(ModelAction * act, SnapList<ModelAction *> * curr_act_list)
 {
+       ASSERT(curr_act_list != NULL);
+
        bool second_part_of_rmw = act->is_rmwc() || act->is_rmw();
        modelclock_t curr_seq_number = act->get_seq_number();
 
@@ -414,6 +476,67 @@ bool ModelHistory::skip_action(ModelAction * act, SnapList<ModelAction *> * curr
        return false;
 }
 
+/* Monitor thread tid and decide whether other threads (that are waiting for tid)
+ * should keep waiting for this thread or not. Shall only be called when a thread
+ * enters a function. 
+ *
+ * Heuristics: If the distance from the current FuncNode to some target node
+ * ever increases, stop waiting for this thread on this target node. 
+ */
+void ModelHistory::monitor_waiting_thread(uint32_t func_id, thread_id_t tid)
+{
+       WaitObj * wait_obj = getWaitObj(tid);
+       thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
+       FuncNode * curr_node = func_nodes[func_id];
+
+       /* For each thread waiting for tid */
+       thrd_id_set_iter * tid_iter = waited_by->iterator();
+       while (tid_iter->hasNext()) {
+               thread_id_t waited_by_id = tid_iter->next();
+               WaitObj * other_wait_obj = getWaitObj(waited_by_id);
+
+               node_set_t * target_nodes = other_wait_obj->getTargetNodes(tid);
+               node_set_iter * node_iter = target_nodes->iterator();
+               while (node_iter->hasNext()) {
+                       FuncNode * target = node_iter->next();
+                       int old_dist = other_wait_obj->lookup_dist(tid, target);
+                       int new_dist = curr_node->compute_distance(target, old_dist);
+
+                       if (new_dist == -1) {
+                               stop_waiting_for_node(waited_by_id, tid, target);
+                       }
+               }
+       }
+}
+
+void ModelHistory::monitor_waiting_thread_counter(thread_id_t tid)
+{
+       WaitObj * wait_obj = getWaitObj(tid);
+       thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
+
+       // Thread tid has taken an action, update the counter for threads waiting for tid
+       thrd_id_set_iter * tid_iter = waited_by->iterator();
+       while (tid_iter->hasNext()) {
+               thread_id_t waited_by_id = tid_iter->next();
+               WaitObj * other_wait_obj = getWaitObj(waited_by_id);
+
+               bool expire = other_wait_obj->incr_counter(tid);
+               if (expire) {
+//                     model_print("thread %d stops waiting for thread %d\n", waited_by_id, tid);
+                       wait_obj->remove_waited_by(waited_by_id);
+                       other_wait_obj->remove_waiting_for(tid);
+
+                       thrd_id_set_t * other_waiting_for = other_wait_obj->getWaitingFor();
+                       if ( other_waiting_for->isEmpty() ) {
+                               // model_print("\tthread %d waits for nobody, wake up\n", self_id);
+                               ModelExecution * execution = model->get_execution();
+                               Thread * thread = execution->get_thread(waited_by_id);
+                               execution->getFuzzer()->notify_paused_thread(thread);
+                       }
+               }
+       }
+}
+
 /* Reallocate some snapshotted memories when new executions start */
 void ModelHistory::set_new_exec_flag()
 {
@@ -464,6 +587,11 @@ void ModelHistory::print_waiting_threads()
                thread_id_t tid = int_to_id(i);
                WaitObj * wait_obj = getWaitObj(tid);
                wait_obj->print_waiting_for();
+       }
+
+       for (unsigned int i = 0; i < execution->get_num_threads();i++) {
+               thread_id_t tid = int_to_id(i);
+               WaitObj * wait_obj = getWaitObj(tid);
                wait_obj->print_waited_by();
        }
 }