/** Initializes a CycleGraph object. */
CycleGraph::CycleGraph() :
- discovered(new HashTable<CycleNode *, CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free>(16)),
+ discovered(new HashTable<const CycleNode *, const CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free>(16)),
hasCycles(false),
- oldCycles(false),
- hasRMWViolation(false),
- oldRMWViolation(false)
+ oldCycles(false)
{
}
/** CycleGraph destructor */
CycleGraph::~CycleGraph()
{
+ delete discovered;
+}
+
+/**
+ * Add a CycleNode to the graph, corresponding to a store ModelAction
+ * @param act The write action that should be added
+ * @param node The CycleNode that corresponds to the store
+ */
+void CycleGraph::putNode(const ModelAction *act, CycleNode *node)
+{
+ actionToNode.put(act, node);
+#if SUPPORT_MOD_ORDER_DUMP
+ nodeList.push_back(node);
+#endif
}
/**
CycleNode *node = actionToNode.get(action);
if (node == NULL) {
node = new CycleNode(action);
- actionToNode.put(action, node);
-#if SUPPORT_MOD_ORDER_DUMP
- nodeList.push_back(node);
-#endif
+ putNode(action, node);
}
return node;
}
CycleNode *fromnode = getNode(from);
CycleNode *tonode = getNode(to);
- if (!hasCycles) {
- // Reflexive edges are cycles
- hasCycles = (from == to);
- }
- if (!hasCycles) {
- // Check for Cycles
+ addEdge(fromnode, tonode);
+}
+
+/**
+ * Adds an edge between two CycleNodes.
+ * @param fromnode The edge comes from this CycleNode
+ * @param tonode The edge points to this CycleNode
+ */
+void CycleGraph::addEdge(CycleNode *fromnode, CycleNode *tonode)
+{
+ if (!hasCycles)
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
+ CycleNode *rmwnode = fromnode->getRMW();
+ if (rmwnode && rmwnode != tonode) {
+ if (!hasCycles)
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.
+/**
+ * @brief Add an edge between a write and the RMW which reads from it
+ *
+ * Handles special case of a RMW action, where 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.
+ * (2) Only one RMW action can read from a given write.
+ *
+ * @param from The edge comes from this ModelAction
+ * @param rmw The edge points to this ModelAction; this action must read from
+ * ModelAction from
*/
void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw)
{
CycleNode *rmwnode = getNode(rmw);
/* Two RMW actions cannot read from the same write. */
- if (fromnode->setRMW(rmwnode)) {
- hasRMWViolation = true;
- } else {
+ if (fromnode->setRMW(rmwnode))
+ hasCycles = 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:
}
}
-
- 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);
- }
- if (fromnode->addEdge(rmwnode))
- rollbackvector.push_back(fromnode);
+ addEdge(fromnode, rmwnode);
}
#if SUPPORT_MOD_ORDER_DUMP
-void CycleGraph::dumpNodes(FILE *file)
+void CycleGraph::dumpNodes(FILE *file) const
{
for (unsigned int i = 0; i < nodeList.size(); i++) {
CycleNode *cn = nodeList[i];
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());
+ 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());
}
}
}
-void CycleGraph::dumpGraphToFile(const char *filename)
+void CycleGraph::dumpGraphToFile(const char *filename) const
{
char buffer[200];
- sprintf(buffer, "%s.dot",filename);
+ sprintf(buffer, "%s.dot", filename);
FILE *file = fopen(buffer, "w");
- fprintf(file, "digraph %s {\n",filename);
+ fprintf(file, "digraph %s {\n", filename);
dumpNodes(file);
- fprintf(file,"}\n");
- fclose(file);
+ fprintf(file, "}\n");
+ fclose(file);
}
#endif
* @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)
+bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) const
{
CycleNode *fromnode = actionToNode.get(from);
CycleNode *tonode = actionToNode.get(to);
* @param to The CycleNode to reach
* @return True, @a from can reach @a to; otherwise, false
*/
-bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to)
+bool CycleGraph::checkReachable(const CycleNode *from, const CycleNode *to) const
{
- std::vector<CycleNode *, ModelAlloc<CycleNode *> > queue;
+ std::vector< const CycleNode *, ModelAlloc<const CycleNode *> > queue;
discovered->reset();
queue.push_back(from);
discovered->put(from, from);
while (!queue.empty()) {
- CycleNode *node = queue.back();
+ const CycleNode *node = queue.back();
queue.pop_back();
if (node == to)
return true;
for (unsigned int i = 0; i < node->getNumEdges(); i++) {
CycleNode *next = node->getEdge(i);
if (!discovered->contains(next)) {
- discovered->put(next,next);
+ discovered->put(next, next);
queue.push_back(next);
}
}
return false;
}
-bool CycleGraph::checkPromise(const ModelAction *fromact, Promise *promise)
+bool CycleGraph::checkPromise(const ModelAction *fromact, Promise *promise) const
{
- std::vector<CycleNode *, ModelAlloc<CycleNode *> > queue;
+ std::vector< CycleNode *, ModelAlloc<CycleNode *> > queue;
discovered->reset();
CycleNode *from = actionToNode.get(fromact);
CycleNode *node = queue.back();
queue.pop_back();
- if (promise->increment_threads(node->getAction()->get_tid())) {
+ if (promise->eliminate_thread(node->getAction()->get_tid())) {
return true;
}
for (unsigned int i = 0; i < node->getNumEdges(); i++) {
CycleNode *next = node->getEdge(i);
if (!discovered->contains(next)) {
- discovered->put(next,next);
+ discovered->put(next, next);
queue.push_back(next);
}
}
void CycleGraph::startChanges()
{
- ASSERT(rollbackvector.size() == 0);
- ASSERT(rmwrollbackvector.size() == 0);
+ ASSERT(rollbackvector.empty());
+ ASSERT(rmwrollbackvector.empty());
ASSERT(oldCycles == hasCycles);
- ASSERT(oldRMWViolation == hasRMWViolation);
}
/** Commit changes to the cyclegraph. */
void CycleGraph::commitChanges()
{
- rollbackvector.resize(0);
- rmwrollbackvector.resize(0);
+ rollbackvector.clear();
+ rmwrollbackvector.clear();
oldCycles = hasCycles;
- oldRMWViolation = hasRMWViolation;
}
/** Rollback changes to the previous commit. */
-void CycleGraph::rollbackChanges() {
- for (unsigned int i = 0; i < rollbackvector.size(); i++) {
+void CycleGraph::rollbackChanges()
+{
+ for (unsigned int i = 0; i < rollbackvector.size(); i++)
rollbackvector[i]->popEdge();
- }
- for (unsigned int i = 0; i < rmwrollbackvector.size(); i++) {
+ for (unsigned int i = 0; i < rmwrollbackvector.size(); i++)
rmwrollbackvector[i]->clearRMW();
- }
hasCycles = oldCycles;
- hasRMWViolation = oldRMWViolation;
- rollbackvector.resize(0);
- rmwrollbackvector.resize(0);
+ rollbackvector.clear();
+ rmwrollbackvector.clear();
}
/** @returns whether a CycleGraph contains cycles. */
-bool CycleGraph::checkForCycles() {
+bool CycleGraph::checkForCycles() const
+{
return hasCycles;
}
-bool CycleGraph::checkForRMWViolation() {
- return hasRMWViolation;
-}
-
/**
- * Constructor for a CycleNode.
- * @param modelaction The ModelAction for this node
+ * @brief Constructor for a CycleNode
+ * @param act The ModelAction for this node
*/
-CycleNode::CycleNode(const ModelAction *modelaction) :
- action(modelaction),
+CycleNode::CycleNode(const ModelAction *act) :
+ action(act),
hasRMW(NULL)
{
}
return edges.size();
}
+CycleNode * CycleNode::getBackEdge(unsigned int i) const
+{
+ return back_edges[i];
+}
+
+unsigned int CycleNode::getNumBackEdges() const
+{
+ return back_edges.size();
+}
+
/**
* Adds an edge from this CycleNode to another CycleNode.
* @param node The node to which we add a directed edge
+ * @return True if this edge is a new edge; false otherwise
*/
bool CycleNode::addEdge(CycleNode *node)
{
if (edges[i] == node)
return false;
edges.push_back(node);
+ node->back_edges.push_back(this);
return true;
}