Compute the threads that a paused thread my wait for

diff --git a/funcnode.cc b/funcnode.cc
index 9228dc773fd7f03cf2b88a3ff42af38f6aaa0795..bf8971bdfbf4de48eba3a53a20323358f3594477 100644 (file)
--- a/funcnode.cc
+++ b/funcnode.cc
@@ -640,6 +640,40 @@ void FuncNode::add_out_edge(FuncNode * other)
        }
 }
 
+int FuncNode::compute_distance(FuncNode * target, int max_step)
+{
+       SnapList<FuncNode *> queue;
+       HashTable<FuncNode *, int, uintptr_t, 0> distances;
+
+       int dist = 0;
+       queue.push_back(this);
+       distances.put(this, dist);
+
+       while (!queue.empty()) {
+               FuncNode * curr = queue.front();
+               queue.pop_front();
+
+               if (curr == target)
+                       return dist;
+               else if (max_step < dist)
+                       return -1;
+
+               dist++;
+               ModelList<FuncNode *> * outEdges = curr->get_out_edges();
+               mllnode<FuncNode *> * it;
+               for (it = outEdges->begin(); it != NULL; it = it->getNext()) {
+                       FuncNode * out_node = it->getVal();
+                       if ( !distances.contains(out_node) ) {
+                               queue.push_back(out_node);
+                               distances.put(out_node, dist);
+                       }
+               }
+       }
+
+       /* Target node is unreachable */
+       return -1;
+}
+
 void FuncNode::print_predicate_tree()
 {
        model_print("digraph function_%s {\n", func_name);

diff --git a/funcnode.h b/funcnode.h
index 0d0755dbed87006d814e737d695fe4b198eb2b70..04665c5cff2886e782b965f243e56bf969d85c05 100644 (file)
--- a/funcnode.h
+++ b/funcnode.h
@@ -5,6 +5,7 @@
 #include "classlist.h"
 #include "threads-model.h"
 
+#define MAX_DIST 10
 typedef ModelList<FuncInst *> func_inst_list_mt;
 
 typedef enum edge_type {
@@ -55,6 +56,7 @@ public:
 
        void add_out_edge(FuncNode * other);
        ModelList<FuncNode *> * get_out_edges() { return &out_edges; }
+       int compute_distance(FuncNode * target, int max_step = MAX_DIST);
 
        void print_predicate_tree();
        void print_val_loc_map();

diff --git a/history.cc b/history.cc
index 3e0644eda314324e472001128f81db6a24b4f930..c3e7eeb0133a594aba5908d9434b1808154ec750 100644 (file)
--- a/history.cc
+++ b/history.cc
@@ -24,7 +24,6 @@ ModelHistory::ModelHistory() :
        loc_waiting_writes_map = new HashTable<void *, SnapVector<ConcretePredicate *> *, uintptr_t, 0>();
        thrd_waiting_write = new SnapVector<ConcretePredicate *>();
        func_inst_act_maps = new HashTable<uint32_t, SnapVector<inst_act_map_t *> *, int, 0>(128);
-       func_threads_map = new HashTable<uint32_t, SnapVector<thread_id_t> *, int, 0>(128);
 }
 
 void ModelHistory::enter_function(const uint32_t func_id, thread_id_t tid)
@@ -247,7 +246,7 @@ SnapVector<FuncNode *> * ModelHistory::getRdFuncNodes(void * location)
        SnapVector<FuncNode *> * func_node_list = loc_rd_func_nodes_map->get(location);
        if (func_node_list == NULL) {
                func_node_list = new SnapVector<FuncNode *>();
-               loc_wr_func_nodes_map->put(location, func_node_list);
+               loc_rd_func_nodes_map->put(location, func_node_list);
        }
 
        return func_node_list;
@@ -397,25 +396,6 @@ bool ModelHistory::skip_action(ModelAction * act, SnapList<ModelAction *> * curr
        return false;
 }
 
-void ModelHistory::update_func_threads_map(uint32_t func_id, thread_id_t tid)
-{
-       SnapVector<thread_id_t> * thread_ids = get_calling_threads(func_id);
-       thread_ids->push_back(tid);
-}
-
-/* Return a vector of thread_id's that have called this function before */
-SnapVector<thread_id_t> * ModelHistory::get_calling_threads(uint32_t func_id)
-{
-       SnapVector<thread_id_t> * thread_ids = func_threads_map->get(func_id);
-       if (thread_ids == NULL) {
-               /* Make sure the result can be iterated without checking nullity */
-               thread_ids = new SnapVector<thread_id_t>();
-               func_threads_map->put(func_id, thread_ids);
-       }
-
-       return thread_ids;
-}
-
 /* Reallocate some snapshotted memories when new executions start */
 void ModelHistory::set_new_exec_flag()
 {

diff --git a/history.h b/history.h
index 869aecf58669b1ac5b2c61dbc0a37b2609fca3bb..2ce88f2f65e45d6f5b6ae83a7334f01afb98431f 100644 (file)
--- a/history.h
+++ b/history.h
@@ -42,9 +42,6 @@ public:
 
        SnapVector<inst_act_map_t *> * getThrdInstActMap(uint32_t func_id);
 
-       void update_func_threads_map(uint32_t func_id, thread_id_t tid);
-       SnapVector<thread_id_t> * get_calling_threads(uint32_t func_id);
-
        void set_new_exec_flag();
        void dump_func_node_graph();
        void print_func_node();
@@ -78,9 +75,6 @@ private:
        HashTable<uint32_t, SnapVector<inst_act_map_t *> *, int, 0> * func_inst_act_maps;
 
        bool skip_action(ModelAction * act, SnapList<ModelAction *> * curr_act_list);
-
-       /* Map func_id to threads that have called this function */
-       HashTable<uint32_t, SnapVector<thread_id_t> *, int, 0> * func_threads_map;
 };
 
 #endif /* __HISTORY_H__ */

diff --git a/newfuzzer.cc b/newfuzzer.cc
index 00219b637550d9a6b77d8a768935a2ff37631508..b0874c85b5c2b2714a1bacd1d5f7194053953846 100644 (file)
--- a/newfuzzer.cc
+++ b/newfuzzer.cc
@@ -44,18 +44,18 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                thrd_last_read_act[thread_id] = read;
 
                FuncNode * func_node = history->get_curr_func_node(tid);
-               inst_act_map_t * inst_act_map = func_node->get_inst_act_map(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);
        }
 
        // 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);
@@ -63,6 +63,9 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set
                execution->restore_last_seq_num();
 
                conditional_sleep(read_thread);
+
+               find_threads(read);
+
                return -1;
 /*
                SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
@@ -214,7 +217,7 @@ void NewFuzzer::conditional_sleep(Thread * 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);
@@ -236,8 +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;
@@ -287,6 +289,32 @@ void NewFuzzer::notify_paused_thread(Thread * thread)
        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;

diff --git a/newfuzzer.h b/newfuzzer.h
index c152c5d98f28a92fedca9af6e1921f3ed0f0e0dc..0e5d483bea9c96d8e0edff2956ecb2c2ed7f93f9 100644 (file)
--- a/newfuzzer.h
+++ b/newfuzzer.h
@@ -42,6 +42,8 @@ private:
 
        void conditional_sleep(Thread * thread);
        void wake_up_paused_threads(int * threadlist, int * numthreads);
+
+       void find_threads(ModelAction * pending_read);
 };
 
 #endif /* end of __NEWFUZZER_H__ */