#include "action.h"
#include "common.h"
#include "promise.h"
-#include "model.h"
+#include "threads-model.h"
/** 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;
}
*/
void CycleGraph::putNode(const Promise *promise, CycleNode *node)
{
- const ModelAction *reader = promise->get_action();
- readerToPromiseNode.put(reader, node);
+ promiseToNode.put(promise, node);
+#if SUPPORT_MOD_ORDER_DUMP
+ nodeList.push_back(node);
+#endif
}
/**
*/
void CycleGraph::erasePromiseNode(const Promise *promise)
{
- const ModelAction *reader = promise->get_action();
- readerToPromiseNode.put(reader, NULL);
+ promiseToNode.put(promise, NULL);
+#if SUPPORT_MOD_ORDER_DUMP
+ /* Remove the promise node from nodeList */
+ CycleNode *node = getNode_noCreate(promise);
+ for (unsigned int i = 0; i < nodeList.size(); )
+ if (nodeList[i] == node)
+ nodeList.erase(nodeList.begin() + i);
+ else
+ i++;
+#endif
}
/** @return The corresponding CycleNode, if exists; otherwise NULL */
/** @return The corresponding CycleNode, if exists; otherwise NULL */
CycleNode * CycleGraph::getNode_noCreate(const Promise *promise) const
{
- return readerToPromiseNode.get(promise->get_action());
+ return promiseToNode.get(promise);
}
/**
}
/**
- * @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(ModelAction *reader, ModelAction *writer,
- promise_list_t *mustResolve)
+bool CycleGraph::resolvePromise(const Promise *promise, ModelAction *writer)
{
- CycleNode *promise_node = readerToPromiseNode.get(reader);
+ 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);
- delete p_node;
+ /* Not deleting p_node, to maintain consistency if mergeNodes() fails */
return !hasCycles;
}
*/
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;
return addNodeEdge(fromnode, tonode);
}
-/* Instantiate three forms of CycleGraph::addEdge */
+/* Instantiate four forms of CycleGraph::addEdge */
template bool CycleGraph::addEdge(const ModelAction *from, const ModelAction *to);
template bool CycleGraph::addEdge(const ModelAction *from, const Promise *to);
template bool CycleGraph::addEdge(const Promise *from, const ModelAction *to);
+template bool CycleGraph::addEdge(const Promise *from, const Promise *to);
#if SUPPORT_MOD_ORDER_DUMP
+
+static void print_node(FILE *file, const CycleNode *node, int label)
+{
+ if (node->is_promise()) {
+ const Promise *promise = node->getPromise();
+ int idx = promise->get_index();
+ fprintf(file, "P%u", idx);
+ if (label) {
+ int first = 1;
+ fprintf(file, " [label=\"P%d, T", idx);
+ for (unsigned int i = 0 ; i < promise->max_available_thread_idx(); i++)
+ if (promise->thread_is_available(int_to_id(i))) {
+ fprintf(file, "%s%u", first ? "": ",", i);
+ first = 0;
+ }
+ fprintf(file, "\"]");
+ }
+ } else {
+ const ModelAction *act = node->getAction();
+ modelclock_t idx = act->get_seq_number();
+ fprintf(file, "N%u", idx);
+ if (label)
+ fprintf(file, " [label=\"N%u, T%u\"]", idx, act->get_tid());
+ }
+}
+
+static void print_edge(FILE *file, const CycleNode *from, const CycleNode *to, const char *prop)
+{
+ print_node(file, from, 0);
+ fprintf(file, " -> ");
+ print_node(file, to, 0);
+ if (prop && strlen(prop))
+ fprintf(file, " [%s]", prop);
+ fprintf(file, ";\n");
+}
+
+void CycleGraph::dot_print_node(FILE *file, const ModelAction *act)
+{
+ print_node(file, getNode(act), 1);
+}
+
+template <typename T, typename U>
+void CycleGraph::dot_print_edge(FILE *file, const T *from, const U *to, const char *prop)
+{
+ CycleNode *fromnode = getNode(from);
+ CycleNode *tonode = getNode(to);
+
+ print_edge(file, fromnode, tonode, prop);
+}
+/* Instantiate two forms of CycleGraph::dot_print_edge */
+template void CycleGraph::dot_print_edge(FILE *file, const Promise *from, const ModelAction *to, const char *prop);
+template void CycleGraph::dot_print_edge(FILE *file, const ModelAction *from, const ModelAction *to, const char *prop);
+
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());
- 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 < cn->getNumEdges(); j++) {
- CycleNode *dst = cn->getEdge(j);
- const ModelAction *dstaction = dst->getAction();
- fprintf(file, "N%u -> N%u;\n", action->get_seq_number(), dstaction->get_seq_number());
- }
+ CycleNode *n = nodeList[i];
+ print_node(file, n, 1);
+ fprintf(file, ";\n");
+ if (n->getRMW())
+ print_edge(file, n, n->getRMW(), "style=dotted");
+ for (unsigned int j = 0; j < n->getNumEdges(); j++)
+ print_edge(file, n, n->getEdge(j), NULL);
}
}
*/
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);
}
}
}
}
/**
- * Checks whether one ModelAction can reach another ModelAction/Promise
- * @param from The ModelAction from which to begin exploration
+ * Checks whether one ModelAction/Promise can reach another ModelAction/Promise
+ * @param from The ModelAction or Promise from which to begin exploration
* @param to The ModelAction or Promise to reach
* @return True, @a from can reach @a to; otherwise, false
*/
-template <typename T>
-bool CycleGraph::checkReachable(const ModelAction *from, const T *to) const
+template <typename T, typename U>
+bool CycleGraph::checkReachable(const T *from, const U *to) const
{
CycleNode *fromnode = getNode_noCreate(from);
CycleNode *tonode = getNode_noCreate(to);
return checkReachable(fromnode, tonode);
}
-/* Instantiate two 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;
if (!node->is_promise() &&
promise->eliminate_thread(node->getAction()->get_tid()))
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) {