some changes towards reading from future writes

[model-checker.git] / nodestack.cc

diff --git a/nodestack.cc b/nodestack.cc
index 409c4e1e52ba431b729ec4b1c6d95168cfbc675b..6295442606612f0feff684f3657756b167239628 100644 (file)
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -25,7 +25,9 @@ Node::Node(ModelAction *act, Node *par, int nthreads)
        backtrack(num_threads),
        numBacktracks(0),
        may_read_from(),
-       read_from_index(0)
+       read_from_index(0),
+       future_values(),
+       future_index(0)
 {
        if (act)
                act->set_node(this);
@@ -55,6 +57,19 @@ void Node::print_may_read_from()
                (*it)->print();
 }
 
+/**
+ * Adds a value from a weakly ordered future write to backtrack to.
+ * @param value is the value to backtrack to.
+ */
+
+void Node::add_future_value(uint64_t value) {
+       for(int i=0;i<future_values.size();i++)
+               if (future_values[i]==value)
+                       return;
+       future_values.push_back(value);
+}
+
+
 /**
  * Checks if the Thread associated with this thread ID has been explored from
  * this Node already.
@@ -86,8 +101,17 @@ bool Node::readsfrom_empty() {
        return ((read_from_index+1)>=may_read_from.size());
 }
 
+/** 
+ * Checks whether the future_values set for this node is empty.
+ * @return true if the future_values set is empty.
+ */
+
+bool Node::futurevalues_empty() {
+       return ((future_index+1)>=future_values.size());
+}
+
 /**
- * Mark the appropriate backtracking infromation for exploring a thread choice.
+ * Mark the appropriate backtracking information for exploring a thread choice.
  * @param act The ModelAction to explore
  */
 void Node::explore_child(ModelAction *act)
@@ -141,6 +165,17 @@ void Node::add_read_from(const ModelAction *act)
        may_read_from.push_back(act);
 }
 
+/**
+ * Gets the next 'future_value' value from this Node. Only valid for a node
+ * where this->action is a 'read'.
+ * @return The first element in future_values
+ */
+
+uint64_t Node::get_future_value() {
+       ASSERT(future_index<future_values.size());
+       return future_values[future_index];
+}
+
 /**
  * Gets the next 'may_read_from' action from this Node. Only valid for a node
  * where this->action is a 'read'.
@@ -162,6 +197,16 @@ bool Node::increment_read_from() {
        return (read_from_index<may_read_from.size());
 }
 
+/**
+ * Increments the index into the future_values set to explore the next item.
+ * @return Returns false if we have explored all values.
+ */
+
+bool Node::increment_future_values() {
+       future_index++;
+       return (future_index<future_values.size());
+}
+
 void Node::explore(thread_id_t tid)
 {
        int i = id_to_int(tid);