/** Initializes a CycleGraph object. */
CycleGraph::CycleGraph() :
discovered(new HashTable<const CycleNode *, const CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free>(16)),
+ queue(new ModelVector<const CycleNode *>()),
hasCycles(false),
oldCycles(false)
{
/** CycleGraph destructor */
CycleGraph::~CycleGraph()
{
+ delete queue;
delete discovered;
}
*/
bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
{
- bool added;
-
- if (!hasCycles)
- hasCycles = checkReachable(tonode, fromnode);
-
- 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 (!hasCycles)
- hasCycles = checkReachable(tonode, rmwnode);
+ if (rmwnode) {
+ while (rmwnode != tonode && rmwnode->getRMW())
+ rmwnode = rmwnode->getRMW();
- if (rmwnode->addEdge(tonode)) {
- 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;
}
/**
*
* Handles special case of a RMW action, where the ModelAction rmw reads from
* the ModelAction/Promise 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.
+ * -# No write can occur in between the @a rmw and @a from actions.
+ * -# Only one RMW action can read from a given write.
*
* @param from The edge comes from this ModelAction/Promise
* @param rmw The edge points to this ModelAction; this action must read from
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;
{
if (node->is_promise()) {
const Promise *promise = node->getPromise();
- int idx = model->get_promise_number(promise);
+ int idx = promise->get_index();
fprintf(file, "P%u", idx);
if (label) {
int first = 1;
*/
bool CycleGraph::checkReachable(const CycleNode *from, const CycleNode *to) const
{
- std::vector< const CycleNode *, ModelAlloc<const CycleNode *> > queue;
discovered->reset();
-
- queue.push_back(from);
+ queue->clear();
+ queue->push_back(from);
discovered->put(from, from);
- while (!queue.empty()) {
- const CycleNode *node = queue.back();
- queue.pop_back();
+ while (!queue->empty()) {
+ 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);
- queue.push_back(next);
+ queue->push_back(next);
}
}
}
return checkReachable(fromnode, tonode);
}
-/* Instantiate three forms of CycleGraph::checkReachable */
+/* Instantiate four forms of CycleGraph::checkReachable */
template bool CycleGraph::checkReachable(const ModelAction *from,
const ModelAction *to) const;
template bool CycleGraph::checkReachable(const ModelAction *from,
const Promise *to) const;
template bool CycleGraph::checkReachable(const Promise *from,
const ModelAction *to) const;
+template bool CycleGraph::checkReachable(const Promise *from,
+ const Promise *to) const;
/** @return True, if the promise has failed; false otherwise */
bool CycleGraph::checkPromise(const ModelAction *fromact, Promise *promise) const
{
- std::vector< CycleNode *, ModelAlloc<CycleNode *> > queue;
discovered->reset();
+ queue->clear();
CycleNode *from = actionToNode.get(fromact);
- queue.push_back(from);
+ queue->push_back(from);
discovered->put(from, from);
- while (!queue.empty()) {
- CycleNode *node = queue.back();
- queue.pop_back();
+ while (!queue->empty()) {
+ const CycleNode *node = queue->back();
+ queue->pop_back();
if (node->getPromise() == promise)
return true;
CycleNode *next = node->getEdge(i);
if (!discovered->contains(next)) {
discovered->put(next, next);
- queue.push_back(next);
+ queue->push_back(next);
}
}
}
return false;
}
+/** @brief Begin a new sequence of graph additions which can be rolled back */
void CycleGraph::startChanges()
{
ASSERT(rollbackvector.empty());
/**
* @param i The index of the edge to return
- * @returns The a CycleNode edge indexed by i
+ * @returns The CycleNode edge indexed by i
*/
CycleNode * CycleNode::getEdge(unsigned int i) const
{
return edges.size();
}
+/**
+ * @param i The index of the back edge to return
+ * @returns The CycleNode back-edge indexed by i
+ */
CycleNode * CycleNode::getBackEdge(unsigned int i) const
{
return back_edges[i];
}
+/** @returns The number of edges entering this CycleNode */
unsigned int CycleNode::getNumBackEdges() const
{
return back_edges.size();
* @return True if the element was found; false otherwise
*/
template <typename T>
-static bool vector_remove_node(std::vector<T, SnapshotAlloc<T> >& v, const T n)
+static bool vector_remove_node(SnapVector<T>& v, const T n)
{
for (unsigned int i = 0; i < v.size(); i++) {
if (v[i] == n) {