Keep track of which FuncNodes may write to a memory location

diff --git a/funcnode.cc b/funcnode.cc
index 93e6b09da46a9c67084194a8145a29a289b71c27..3db022695ece62edb0e775f7ea1746fc1b83319c 100644 (file)
--- a/funcnode.cc
+++ b/funcnode.cc
@@ -13,9 +13,10 @@ FuncNode::FuncNode(ModelHistory * history) :
        predicate_tree_entry = new Predicate(NULL, true);
        predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
 
-       // memories that are reclaimed after each execution
+       // Memories that are reclaimed after each execution
        action_list_buffer = new SnapList<action_list_t *>();
        read_locations = new loc_set_t();
+       write_locations = new loc_set_t();
        val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
        loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
        thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
@@ -33,6 +34,7 @@ void FuncNode::set_new_exec_flag()
 
        action_list_buffer = new SnapList<action_list_t *>();
        read_locations = new loc_set_t();
+       write_locations = new loc_set_t();
        val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
        loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
        thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
@@ -143,23 +145,28 @@ void FuncNode::update_tree(action_list_t * act_list)
        for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
                ModelAction * act = it->getVal();
                FuncInst * func_inst = get_inst(act);
+               void * loc = act->get_location();
 
                if (func_inst == NULL)
                        continue;
 
                inst_list.push_back(func_inst);
+               bool act_added = false;
 
-               /* NOTE: for rmw actions, func_inst and act may have different
-                * action types because of action type conversion in ModelExecution
-                * func_inst->is_write() <==> pure writes (excluding rmw) */
-               if (func_inst->is_write()) {
-                       // model_print("write detected\n");
+               if (act->is_write()) {
                        rw_act_list.push_back(act);
+                       act_added = true;
+                       if (!write_locations->contains(loc)) {
+                               write_locations->add(loc);
+                               history->update_loc_wr_func_nodes_map(loc, this);
+                       }
+
                }
 
-               /* func_inst->is_read() <==> read + rmw */
-               if (func_inst->is_read()) {
-                       rw_act_list.push_back(act);
+               if (act->is_read()) {
+                       if (!act_added)
+                               rw_act_list.push_back(act);
+
                        /* If func_inst may only read_from a single location, then:
                         *
                         * The first time an action reads from some location,
@@ -167,12 +174,11 @@ void FuncNode::update_tree(action_list_t * act_list)
                         * location from ModelHistory and notify ModelHistory
                         * that this FuncNode may read from this location.
                         */
-                       void * loc = act->get_location();
                        if (!read_locations->contains(loc) && func_inst->is_single_location()) {
                                read_locations->add(loc);
                                value_set_t * write_values = write_history->get(loc);
                                add_to_val_loc_map(write_values, loc);
-                               history->add_to_loc_func_nodes_map(loc, this);
+                               history->update_loc_func_nodes_map(loc, this);
                        }
                }
        }

diff --git a/funcnode.h b/funcnode.h
index 3a353fd82026bd61f9c4c398b98d2fcab4c7a770..22d92835ca1c4b749b1f3211c19941bc0249e2b9 100644 (file)
--- a/funcnode.h
+++ b/funcnode.h
@@ -91,13 +91,18 @@ private:
        /* Store action_lists when calls to update_tree are deferred */
        SnapList<action_list_t *> * action_list_buffer;
 
-       /* read_locations: set of locations read by this FuncNode
-        * val_loc_map: keep track of locations that have the same values written to;
-        * loc_may_equal_map: look up locations that may share the same value as key; 
-        *                      deduced from val_loc_map;       */
+       /* Set of locations read by this FuncNode */
        loc_set_t * read_locations;
+
+       /* Set of locations written to by this FuncNode */
+       loc_set_t * write_locations;
+
+       /* Keeps track of locations that have the same values written to */
        HashTable<uint64_t, loc_set_t *, uint64_t, 0> * val_loc_map;
+
+       /* Keeps track of locations that may share the same value as key, deduced from val_loc_map */
        HashTable<void *, loc_set_t *, uintptr_t, 0> * loc_may_equal_map;
+
        // value_set_t * values_may_read_from;
 
        /* Run-time position in the predicate tree for each thread */
@@ -108,7 +113,9 @@ private:
 
        /* Store the relation between this FuncNode and other FuncNodes */
        HashTable<FuncNode *, edge_type_t, uintptr_t, 0, model_malloc, model_calloc, model_free> edge_table;
-       ModelList<FuncNode *> out_edges;        /* FuncNodes that follow this node */
+
+       /* FuncNodes that follow this node */
+       ModelList<FuncNode *> out_edges;
 };
 
 #endif /* __FUNCNODE_H__ */

diff --git a/history.cc b/history.cc
index cb5307a92e254d4e4f1b1d5ed08d414750fa09f7..568cecb520ee49f7a42249b2191a9fc924104a17 100644 (file)
--- a/history.cc
+++ b/history.cc
@@ -144,17 +144,16 @@ void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
        if (act->is_write()) {
                void * location = act->get_location();
                uint64_t value = act->get_write_value();
-               add_to_write_history(location, value);
+               update_write_history(location, value);
 
-               /* update FuncNodes */
+               /* Update FuncNodes that may read from this location */
                SnapList<FuncNode *> * func_nodes = loc_func_nodes_map.get(location);
-               sllnode<FuncNode *> * it = NULL;
-               if (func_nodes != NULL)
-                       it = func_nodes->begin();
-
-               for (; it != NULL; it = it->getNext()) {
-                       FuncNode * func_node = it->getVal();
-                       func_node->add_to_val_loc_map(value, location);
+               if (func_nodes != NULL) {
+                       sllnode<FuncNode *> * it = func_nodes->begin();
+                       for (; it != NULL; it = it->getNext()) {
+                               FuncNode * func_node = it->getVal();
+                               func_node->add_to_val_loc_map(value, location);
+                       }
                }
        }
 
@@ -167,19 +166,17 @@ void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
        action_list_t * curr_act_list = func_act_lists->back();
        ASSERT(curr_act_list != NULL);
 
-       ModelAction * last_act = NULL;
-       if (curr_act_list->size() != 0)
-               last_act = curr_act_list->back();
-
-       /* skip actions that are paused by fuzzer (sequence number is 0), 
-        * that are second part of a read modify write or actions with the same sequence number */
        modelclock_t curr_seq_number = act->get_seq_number();
-       if (curr_seq_number == 0 || second_part_of_rmw ||
-               (last_act != NULL && last_act->get_seq_number() == curr_seq_number) )
-               return;
+       /* Skip actions that are second part of a read modify write or actions with the same sequence number */
+       if (curr_act_list->size() != 0) {
+               ModelAction * last_act = curr_act_list->back();
+               if (second_part_of_rmw || last_act->get_seq_number() == curr_seq_number)
+                       return;
+       }
 
-       if ( func_nodes.size() <= func_id )
-               resize_func_nodes( func_id + 1 );
+       /* skip actions that are paused by fuzzer (sequence number is 0) */
+       if (curr_seq_number == 0)
+               return;
 
        FuncNode * func_node = func_nodes[func_id];
 
@@ -206,7 +203,7 @@ FuncNode * ModelHistory::get_func_node(uint32_t func_id)
        return func_nodes[func_id];
 }
 
-void ModelHistory::add_to_write_history(void * location, uint64_t write_val)
+void ModelHistory::update_write_history(void * location, uint64_t write_val)
 {
        value_set_t * write_set = write_history.get(location);
 
@@ -218,7 +215,7 @@ void ModelHistory::add_to_write_history(void * location, uint64_t write_val)
        write_set->add(write_val);
 }
 
-void ModelHistory::add_to_loc_func_nodes_map(void * location, FuncNode * node)
+void ModelHistory::update_loc_func_nodes_map(void * location, FuncNode * node)
 {
        SnapList<FuncNode *> * func_node_list = loc_func_nodes_map.get(location);
        if (func_node_list == NULL) {
@@ -229,6 +226,17 @@ void ModelHistory::add_to_loc_func_nodes_map(void * location, FuncNode * node)
        func_node_list->push_back(node);
 }
 
+void ModelHistory::update_loc_wr_func_nodes_map(void * location, FuncNode * node)
+{
+       SnapList<FuncNode *> * func_node_list = loc_wr_func_nodes_map.get(location);
+       if (func_node_list == NULL) {
+               func_node_list = new SnapList<FuncNode *>();
+               loc_func_nodes_map.put(location, func_node_list);
+       }
+
+       func_node_list->push_back(node);
+}
+
 /* Reallocate some snapshotted memories when new executions start */
 void ModelHistory::set_new_exec_flag()
 {

diff --git a/history.h b/history.h
index ee07ba4f17ef443e3a2594d69054edefcc8213c4..e85aa81a18ce4e4d4c6979ce2291c154c624726d 100644 (file)
--- a/history.h
+++ b/history.h
@@ -27,9 +27,10 @@ public:
        ModelVector<FuncNode *> * getFuncNodes() { return &func_nodes; }
        FuncNode * get_func_node(uint32_t func_id);
 
-       void add_to_write_history(void * location, uint64_t write_val);
+       void update_write_history(void * location, uint64_t write_val);
        HashTable<void *, value_set_t *, uintptr_t, 4> * getWriteHistory() { return &write_history; }
-       void add_to_loc_func_nodes_map(void * location, FuncNode * node);
+       void update_loc_func_nodes_map(void * location, FuncNode * node);
+       void update_loc_wr_func_nodes_map(void * location, FuncNode * node);
 
        void set_new_exec_flag();
        void dump_func_node_graph();
@@ -47,11 +48,16 @@ private:
 
        ModelVector<FuncNode *> func_nodes;
 
+       /* Map a location to a set of values that have been written to it */
        HashTable<void *, value_set_t *, uintptr_t, 4> write_history;
 
        /* Map a location to FuncNodes that may read from it */
        HashTable<void *, SnapList<FuncNode *> *, uintptr_t, 4> loc_func_nodes_map;
 
+       /* Map a location to FuncNodes that may write to it */
+       HashTable<void *, SnapList<FuncNode *> *, uintptr_t, 4> loc_wr_func_nodes_map;
+
+       /* Keeps track of the last function entered by each thread */
        SnapVector<uint32_t> thrd_last_entered_func;
        void add_edges_between(FuncNode * prev_node, FuncNode * next_node);
 };