switch everything over to our own hashtable

[model-checker.git] / nodestack.cc

diff --git a/nodestack.cc b/nodestack.cc
index 2416ed7c5b35d23deadd2f2681cd890a926e7f98..e8f377b51a6dfbca7e59dc69b1a81a5b19cac196 100644 (file)
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -24,7 +24,8 @@ Node::Node(ModelAction *act, Node *par, int nthreads)
        explored_children(num_threads),
        backtrack(num_threads),
        numBacktracks(0),
-       may_read_from()
+       may_read_from(),
+       read_from_index(0)
 {
        if (act)
                act->set_node(this);
@@ -73,7 +74,16 @@ bool Node::has_been_explored(thread_id_t tid)
  */
 bool Node::backtrack_empty()
 {
-       return numBacktracks == 0;
+       return (numBacktracks == 0);
+}
+
+
+/**
+ * Checks whether the readsfrom set for this node is empty.
+ * @return true if the readsfrom set is empty.
+ */
+bool Node::readsfrom_empty() {
+       return ((read_from_index+1)>=may_read_from.size());
 }
 
 /**
@@ -109,8 +119,9 @@ thread_id_t Node::get_next_backtrack()
        for (i = 0; i < backtrack.size(); i++)
                if (backtrack[i] == true)
                        break;
-       if (i >= backtrack.size())
-               return THREAD_ID_T_NONE;
+       /* Backtrack set was empty? */
+       ASSERT(i != backtrack.size());
+
        backtrack[i] = false;
        numBacktracks--;
        return int_to_id(i);
@@ -137,13 +148,18 @@ void Node::add_read_from(const ModelAction *act)
  * may remove elements from may_read_from
  * @return The first element in may_read_from
  */
-const ModelAction * Node::get_next_read_from() {
-       const ModelAction *act;
-       ASSERT(!may_read_from.empty());
-       act = may_read_from.front();
-       /* TODO: perform reads_from replay properly */
-       /* may_read_from.pop_front(); */
-       return act;
+const ModelAction * Node::get_read_from() {
+       ASSERT(read_from_index<may_read_from.size());
+       return may_read_from[read_from_index];
+}
+
+/**
+ * Increments the index into the readsfrom set to explore the next item.
+ * @return Returns false if we have explored all items.
+ */
+bool Node::increment_read_from() {
+       read_from_index++;
+       return (read_from_index<may_read_from.size());
 }
 
 void Node::explore(thread_id_t tid)
@@ -197,17 +213,14 @@ ModelAction * NodeStack::explore_action(ModelAction *act)
        DBG();
 
        ASSERT(!node_list.empty());
+       node_list_t::iterator it=iter;
+       it++;
 
-       if (get_head()->has_been_explored(act->get_tid())) {
+       if (it != node_list.end()) {
                iter++;
                return (*iter)->get_action();
        }
 
-       /* Diverging from previous execution; clear out remainder of list */
-       node_list_t::iterator it = iter;
-       it++;
-       clear_node_list(&node_list, it, node_list.end());
-
        /* Record action */
        get_head()->explore_child(act);
        node_list.push_back(new Node(act, get_head(), model->get_num_threads()));
@@ -216,6 +229,23 @@ ModelAction * NodeStack::explore_action(ModelAction *act)
        return NULL;
 }
 
+/**
+ * Empties the stack of all trailing nodes after a given position and calls the
+ * destructor for each. This function is provided an offset which determines
+ * how many nodes (relative to the current replay state) to save before popping
+ * the stack.
+ * @param numAhead gives the number of Nodes (including this Node) to skip over
+ * before removing nodes.
+ */
+void NodeStack::pop_restofstack(int numAhead)
+{
+       /* Diverging from previous execution; clear out remainder of list */
+       node_list_t::iterator it = iter;
+       while (numAhead--)
+               it++;
+       clear_node_list(&node_list, it, node_list.end());
+}
+
 Node * NodeStack::get_head()
 {
        if (node_list.empty())