X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=cyclegraph.cc;h=26ea215d434921f2b27fd69e07ef18d1e6029f54;hb=d62cd6e5bbba2975923540d99bae0587fe03b791;hp=8d37dea8b9fc6ea6770528e57238df13d2b5a323;hpb=cfbcbb33437af392cea2a5092d89cfed47506b75;p=model-checker.git

diff --git a/cyclegraph.cc b/cyclegraph.cc
index 8d37dea..26ea215 100644
--- a/cyclegraph.cc
+++ b/cyclegraph.cc
@@ -198,29 +198,33 @@ bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node)
  */
 bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
 {
-	bool added;
-
-	if ((added = fromnode->addEdge(tonode))) {
+	if (fromnode->addEdge(tonode)) {
 		rollbackvector.push_back(fromnode);
 		if (!hasCycles)
 			hasCycles = checkReachable(tonode, fromnode);
-	}
+	} else
+		return false; /* No new edge */
 
 	/*
-	 * If the fromnode has a rmwnode that is not the tonode, we should add
-	 * an edge between its rmwnode and the tonode
+	 * If the fromnode has a rmwnode that is not the tonode, we should
+	 * follow its RMW chain to add an edge at the end, unless we encounter
+	 * tonode along the way
 	 */
 	CycleNode *rmwnode = fromnode->getRMW();
-	if (rmwnode && rmwnode != tonode) {
-		if (rmwnode->addEdge(tonode)) {
-			if (!hasCycles)
-				hasCycles = checkReachable(tonode, rmwnode);
+	if (rmwnode) {
+		while (rmwnode != tonode && rmwnode->getRMW())
+			rmwnode = rmwnode->getRMW();
 
-			rollbackvector.push_back(rmwnode);
-			added = true;
+		if (rmwnode != tonode) {
+			if (rmwnode->addEdge(tonode)) {
+				if (!hasCycles)
+					hasCycles = checkReachable(tonode, rmwnode);
+
+				rollbackvector.push_back(rmwnode);
+			}
 		}
 	}
-	return added;
+	return true;
 }
 
 /**
@@ -244,6 +248,9 @@ void CycleGraph::addRMWEdge(const T *from, const ModelAction *rmw)
 	CycleNode *fromnode = getNode(from);
 	CycleNode *rmwnode = getNode(rmw);
 
+	/* We assume that this RMW has no RMW reading from it yet */
+	ASSERT(!rmwnode->getRMW());
+
 	/* Two RMW actions cannot read from the same write. */
 	if (fromnode->setRMW(rmwnode))
 		hasCycles = true;