+ hasCycles = checkReachable(tonode, fromnode);
+ }
+
+ if (fromnode->addEdge(tonode))
+ rollbackvector.push_back(fromnode);
+
+
+ CycleNode *rmwnode = fromnode->getRMW();
+
+ /*
+ * If the fromnode has a rmwnode that is not the tonode, we should add
+ * an edge between its rmwnode and the tonode
+ *
+ * If tonode is also a rmw, don't do this check as the execution is
+ * doomed and we'll catch the problem elsewhere, but we want to allow
+ * for the possibility of sending to's write value to rmwnode
+ */
+ if (rmwnode != NULL && !to->is_rmw()) {
+ if (!hasCycles) {
+ // Check for Cycles
+ hasCycles = checkReachable(tonode, rmwnode);
+ }
+
+ if (rmwnode->addEdge(tonode))
+ rollbackvector.push_back(rmwnode);
+ }
+}
+
+/** Handles special case of a RMW action. The ModelAction rmw reads
+ * from the ModelAction from. The key differences are: (1) no write
+ * can occur in between the rmw and the from action. Only one RMW
+ * action can read from a given write.
+ */
+void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw)
+{
+ ASSERT(from);
+ ASSERT(rmw);
+
+ CycleNode *fromnode = getNode(from);
+ CycleNode *rmwnode = getNode(rmw);
+
+ /* Two RMW actions cannot read from the same write. */
+ if (fromnode->setRMW(rmwnode)) {
+ hasRMWViolation = true;
+ } else {
+ rmwrollbackvector.push_back(fromnode);
+ }
+
+ /* Transfer all outgoing edges from the from node to the rmw node */
+ /* This process should not add a cycle because either:
+ * (1) The rmw should not have any incoming edges yet if it is the
+ * new node or
+ * (2) the fromnode is the new node and therefore it should not
+ * have any outgoing edges.
+ */
+ for (unsigned int i = 0; i < fromnode->getNumEdges(); i++) {
+ CycleNode *tonode = fromnode->getEdge(i);
+ if (tonode != rmwnode) {
+ if (rmwnode->addEdge(tonode))
+ rollbackvector.push_back(rmwnode);
+ }
+ }
+
+
+ if (!hasCycles) {
+ // Reflexive edges are cycles
+ hasCycles = (from == rmw);
+ }
+ if (!hasCycles) {
+ // With promises we could be setting up a cycle here if we aren't
+ // careful...avoid it..
+ hasCycles = checkReachable(rmwnode, fromnode);