/** 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;
}
}
/**
- * @return false if the resolution results in a cycle; true otherwise
+ * Resolve/satisfy a Promise with a particular store ModelAction, taking care
+ * of the CycleGraph cleanups, including merging any necessary CycleNodes.
+ *
+ * @param promise The Promise to resolve
+ * @param writer The store that will resolve this Promise
+ * @return false if the resolution results in a cycle (or fails in some other
+ * way); true otherwise
*/
-bool CycleGraph::resolvePromise(const Promise *promise, ModelAction *writer,
- promise_list_t *mustResolve)
+bool CycleGraph::resolvePromise(const Promise *promise, ModelAction *writer)
{
CycleNode *promise_node = promiseToNode.get(promise);
CycleNode *w_node = actionToNode.get(writer);
ASSERT(promise_node);
if (w_node)
- return mergeNodes(w_node, promise_node, mustResolve);
+ return mergeNodes(w_node, promise_node);
/* No existing write-node; just convert the promise-node */
promise_node->resolvePromise(writer);
erasePromiseNode(promise_node->getPromise());
* @param w_node The write ModelAction node with which to merge
* @param p_node The Promise node to merge. Will be destroyed after this
* function.
- * @param mustMerge Return (pass-by-reference) any additional Promises that
- * must also be merged with w_node
*
- * @return false if the merge results in a cycle; true otherwise
+ * @return false if the merge cannot succeed; true otherwise
*/
-bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node,
- promise_list_t *mustMerge)
+bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node)
{
ASSERT(!w_node->is_promise());
ASSERT(p_node->is_promise());
const Promise *promise = p_node->getPromise();
- if (!promise->is_compatible(w_node->getAction())) {
- hasCycles = true;
+ if (!promise->is_compatible(w_node->getAction()) ||
+ !promise->same_value(w_node->getAction()))
return false;
- }
/* Transfer the RMW */
CycleNode *promise_rmw = p_node->getRMW();
- if (promise_rmw && promise_rmw != w_node->getRMW() && w_node->setRMW(promise_rmw)) {
- hasCycles = true;
+ if (promise_rmw && promise_rmw != w_node->getRMW() && w_node->setRMW(promise_rmw))
return false;
- }
/* Transfer back edges to w_node */
while (p_node->getNumBackEdges() > 0) {
CycleNode *back = p_node->removeBackEdge();
if (back == w_node)
continue;
- if (back->is_promise()) {
- if (checkReachable(w_node, back)) {
- /* Edge would create cycle; merge instead */
- mustMerge->push_back(back->getPromise());
- if (!mergeNodes(w_node, back, mustMerge))
- return false;
- } else
- back->addEdge(w_node);
- } else
- addNodeEdge(back, w_node);
+ addNodeEdge(back, w_node);
+ if (hasCycles)
+ return false;
}
/* Transfer forward edges to w_node */
CycleNode *forward = p_node->removeEdge();
if (forward == w_node)
continue;
- if (forward->is_promise()) {
- if (checkReachable(forward, w_node)) {
- mustMerge->push_back(forward->getPromise());
- if (!mergeNodes(w_node, forward, mustMerge))
- return false;
- } else
- w_node->addEdge(forward);
- } else
- addNodeEdge(w_node, forward);
+ addNodeEdge(w_node, forward);
+ if (hasCycles)
+ return false;
}
erasePromiseNode(promise);
*/
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 != tonode) {
+ if (rmwnode->addEdge(tonode)) {
+ if (!hasCycles)
+ hasCycles = checkReachable(tonode, rmwnode);
- if (rmwnode->addEdge(tonode)) {
- rollbackvector.push_back(rmwnode);
- added = true;
+ rollbackvector.push_back(rmwnode);
+ }
}
}
- return added;
+ return true;
}
/**
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;
*/
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 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) {
projects / model-checker.git / blobdiff