cyclegraph: return 'added' status for addEdge()

The ModelChecker would like to know if it's adding a new edge, or just
and existing edge. If the edge is not new, then there are fewer
resulting update checks needed.

diff --git a/cyclegraph.cc b/cyclegraph.cc
index 3bb5ab84a88c240d11ee5b7ae1ed01d2ab7c7207..eaddc8e1714629f8834a5b11c891f8009b2e1237 100644 (file)
--- a/cyclegraph.cc
+++ b/cyclegraph.cc
@@ -168,13 +168,16 @@ bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node,
  * Adds an edge between two CycleNodes.
  * @param fromnode The edge comes from this CycleNode
  * @param tonode The edge points to this CycleNode
+ * @return True, if new edge(s) are added; otherwise false
  */
-void CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
+bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
 {
+       bool added;
+
        if (!hasCycles)
                hasCycles = checkReachable(tonode, fromnode);
 
-       if (fromnode->addEdge(tonode))
+       if ((added = fromnode->addEdge(tonode)))
                rollbackvector.push_back(fromnode);
 
        /*
@@ -186,9 +189,12 @@ void CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
                if (!hasCycles)
                        hasCycles = checkReachable(tonode, rmwnode);
 
-               if (rmwnode->addEdge(tonode))
+               if (rmwnode->addEdge(tonode)) {
                        rollbackvector.push_back(rmwnode);
+                       added = true;
+               }
        }
+       return added;
 }
 
 /**

diff --git a/cyclegraph.h b/cyclegraph.h
index 83d3db21d77cdfc192f0bd286d21fee188de7fac..749abf8ca847d9969016356101b153c4d0688a84 100644 (file)
--- a/cyclegraph.h
+++ b/cyclegraph.h
@@ -28,7 +28,7 @@ class CycleGraph {
        ~CycleGraph();
 
        template <typename T, typename U>
-       void addEdge(const T from, const U to);
+       bool addEdge(const T from, const U to);
 
        bool checkForCycles() const;
        void addRMWEdge(const ModelAction *from, const ModelAction *rmw);
@@ -50,7 +50,7 @@ class CycleGraph {
 
        SNAPSHOTALLOC
  private:
-       void addNodeEdge(CycleNode *fromnode, CycleNode *tonode);
+       bool addNodeEdge(CycleNode *fromnode, CycleNode *tonode);
        void putNode(const ModelAction *act, CycleNode *node);
        CycleNode * getNode(const ModelAction *act);
        CycleNode * getNode(const Promise *promise);
@@ -141,9 +141,10 @@ class CycleNode {
  *
  * @param to The edge points to this object, of type T
  * @param from The edge comes from this object, of type U
+ * @return True, if new edge(s) are added; otherwise false
  */
 template <typename T, typename U>
-void CycleGraph::addEdge(const T from, const U to)
+bool CycleGraph::addEdge(const T from, const U to)
 {
        ASSERT(from);
        ASSERT(to);
@@ -151,7 +152,7 @@ void CycleGraph::addEdge(const T from, const U to)
        CycleNode *fromnode = getNode(from);
        CycleNode *tonode = getNode(to);
 
-       addNodeEdge(fromnode, tonode);
+       return addNodeEdge(fromnode, tonode);
 }
 
 /**