+/** 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);
+ ASSERT(from != 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.
+ */
+ std::vector<CycleNode *> * edges=fromnode->getEdges();
+ for(unsigned int i=0;i<edges->size();i++) {
+ CycleNode * tonode=(*edges)[i];
+ if (tonode!=rmwnode) {
+ if (rmwnode->addEdge(tonode))
+ rollbackvector.push_back(rmwnode);
+ }
+ }
+
+
+ if (!hasCycles) {
+ // With promises we could be setting up a cycle here if we aren't
+ // careful...avoid it..
+ hasCycles=checkReachable(rmwnode, fromnode);
+ }
+ if(fromnode->addEdge(rmwnode))
+ rollbackvector.push_back(fromnode);
+}
+
+#if SUPPORT_MOD_ORDER_DUMP
+void CycleGraph::dumpNodes(FILE *file) {
+ for(unsigned int i=0;i<nodeList.size();i++) {
+ CycleNode *cn=nodeList[i];
+ std::vector<CycleNode *> * edges=cn->getEdges();
+ const ModelAction *action=cn->getAction();
+ fprintf(file, "N%u [label=\"%u, T%u\"];\n",action->get_seq_number(),action->get_seq_number(), action->get_tid());
+ if (cn->getRMW()!=NULL) {
+ fprintf(file, "N%u -> N%u[style=dotted];\n", action->get_seq_number(), cn->getRMW()->getAction()->get_seq_number());
+ }
+ for(unsigned int j=0;j<edges->size();j++) {
+ CycleNode *dst=(*edges)[j];
+ const ModelAction *dstaction=dst->getAction();
+ fprintf(file, "N%u -> N%u;\n", action->get_seq_number(), dstaction->get_seq_number());
+ }
+ }
+}
+
+void CycleGraph::dumpGraphToFile(const char *filename) {
+ char buffer[200];
+ sprintf(buffer, "%s.dot",filename);
+ FILE *file=fopen(buffer, "w");
+ fprintf(file, "digraph %s {\n",filename);
+ dumpNodes(file);
+ fprintf(file,"}\n");
+ fclose(file);
+}
+#endif
+
+/**
+ * Checks whether one ModelAction can reach another.
+ * @param from The ModelAction from which to begin exploration
+ * @param to The ModelAction to reach
+ * @return True, @a from can reach @a to; otherwise, false
+ */
+bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) {
+ CycleNode *fromnode = actionToNode.get(from);
+ CycleNode *tonode = actionToNode.get(to);
+
+ if (!fromnode || !tonode)
+ return false;
+
+ return checkReachable(fromnode, tonode);
+}
+
+/**
+ * Checks whether one CycleNode can reach another.
+ * @param from The CycleNode from which to begin exploration
+ * @param to The CycleNode to reach
+ * @return True, @a from can reach @a to; otherwise, false
+ */