#include "cyclegraph.h"
#include "action.h"
#include "common.h"
-#include "promise.h"
-#include "model.h"
#include "threads-model.h"
+#include "clockvector.h"
/** Initializes a CycleGraph object. */
CycleGraph::CycleGraph() :
- discovered(new HashTable<const CycleNode *, const CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free>(16)),
- hasCycles(false),
- oldCycles(false)
+ queue(new SnapVector<const CycleNode *>())
{
}
/** CycleGraph destructor */
CycleGraph::~CycleGraph()
{
- delete discovered;
+ delete queue;
}
/**
#endif
}
-/**
- * Add a CycleNode to the graph, corresponding to a Promise
- * @param promise The Promise that should be added
- * @param node The CycleNode that corresponds to the Promise
- */
-void CycleGraph::putNode(const Promise *promise, CycleNode *node)
-{
- promiseToNode.put(promise, node);
-#if SUPPORT_MOD_ORDER_DUMP
- nodeList.push_back(node);
-#endif
-}
-
-/**
- * @brief Remove the Promise node from the graph
- * @param promise The promise to remove from the graph
- */
-void CycleGraph::erasePromiseNode(const Promise *promise)
-{
- 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 */
CycleNode * CycleGraph::getNode_noCreate(const ModelAction *act) const
{
return actionToNode.get(act);
}
-/** @return The corresponding CycleNode, if exists; otherwise NULL */
-CycleNode * CycleGraph::getNode_noCreate(const Promise *promise) const
-{
- return promiseToNode.get(promise);
-}
-
/**
* @brief Returns the CycleNode corresponding to a given ModelAction
*
return node;
}
-/**
- * @brief Returns a CycleNode corresponding to a promise
- *
- * Gets (or creates, if none exist) a CycleNode corresponding to a promised
- * value.
- *
- * @param promise The Promise generated by a reader
- * @return The CycleNode corresponding to the Promise
- */
-CycleNode * CycleGraph::getNode(const Promise *promise)
-{
- CycleNode *node = getNode_noCreate(promise);
- if (node == NULL) {
- node = new CycleNode(promise);
- putNode(promise, node);
- }
- return node;
-}
-
-/**
- * @return false if the resolution results in a cycle; true otherwise
- */
-bool CycleGraph::resolvePromise(const Promise *promise, ModelAction *writer,
- promise_list_t *mustResolve)
-{
- 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);
- /* No existing write-node; just convert the promise-node */
- promise_node->resolvePromise(writer);
- erasePromiseNode(promise_node->getPromise());
- putNode(writer, promise_node);
- return true;
-}
-
-/**
- * @brief Merge two CycleNodes that represent the same write
- *
- * Note that this operation cannot be rolled back.
- *
- * @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
- */
-bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node,
- promise_list_t *mustMerge)
-{
- 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;
- 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;
- 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);
- }
-
- /* Transfer forward edges to w_node */
- while (p_node->getNumEdges() > 0) {
- 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);
- }
-
- erasePromiseNode(promise);
- /* Not deleting p_node, to maintain consistency if mergeNodes() fails */
-
- return !hasCycles;
-}
-
/**
* Adds an edge between two CycleNodes.
* @param fromnode The edge comes from this CycleNode
* @param tonode The edge points to this CycleNode
* @return True, if new edge(s) are added; otherwise false
*/
-bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
+void CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode, bool forceedge)
{
- bool added;
-
- if (!hasCycles)
- hasCycles = checkReachable(tonode, fromnode);
-
- if ((added = fromnode->addEdge(tonode)))
- rollbackvector.push_back(fromnode);
+ //quick check whether edge is redundant
+ if (checkReachable(fromnode, tonode) && !forceedge) {
+ return;
+ }
/*
- * 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, we should
+ * follow its RMW chain to add an edge at the end.
*/
- CycleNode *rmwnode = fromnode->getRMW();
- if (rmwnode && rmwnode != tonode) {
- if (!hasCycles)
- hasCycles = checkReachable(tonode, rmwnode);
-
- if (rmwnode->addEdge(tonode)) {
- rollbackvector.push_back(rmwnode);
- added = true;
+ while (fromnode->getRMW()) {
+ CycleNode *nextnode = fromnode->getRMW();
+ if (nextnode == tonode)
+ break;
+ fromnode = nextnode;
+ }
+
+ fromnode->addEdge(tonode); //Add edge to edgeSrcNode
+
+ /* Propagate clock vector changes */
+ if (tonode->cv->merge(fromnode->cv)) {
+ queue->push_back(fromnode);
+ while(!queue->empty()) {
+ const CycleNode *node = queue->back();
+ queue->pop_back();
+ unsigned int numedges = node->getNumEdges();
+ for(unsigned int i = 0;i < numedges;i++) {
+ CycleNode * enode = node->getEdge(i);
+ if (enode->cv->merge(node->cv))
+ queue->push_back(enode);
+ }
}
}
- return added;
}
/**
* @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/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.
+ * the ModelAction from. The key differences are:
+ * -# 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 from The edge comes from this ModelAction
* @param rmw The edge points to this ModelAction; this action must read from
- * the ModelAction/Promise from
+ * the ModelAction from
*/
-template <typename T>
-void CycleGraph::addRMWEdge(const T *from, const ModelAction *rmw)
+void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw)
{
ASSERT(from);
ASSERT(rmw);
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;
- else
- rmwrollbackvector.push_back(fromnode);
+ fromnode->setRMW(rmwnode);
/* Transfer all outgoing edges from the from node to the rmw node */
/* This process should not add a cycle because either:
* (2) the fromnode is the new node and therefore it should not
* have any outgoing edges.
*/
- for (unsigned int i = 0; i < fromnode->getNumEdges(); i++) {
+ for (unsigned int i = 0;i < fromnode->getNumEdges();i++) {
CycleNode *tonode = fromnode->getEdge(i);
if (tonode != rmwnode) {
- if (rmwnode->addEdge(tonode))
- rollbackvector.push_back(rmwnode);
+ rmwnode->addEdge(tonode);
}
}
+ fromnode->edges.clear();
- addNodeEdge(fromnode, rmwnode);
+ addNodeEdge(fromnode, rmwnode, true);
}
-/* Instantiate two forms of CycleGraph::addRMWEdge */
-template void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw);
-template void CycleGraph::addRMWEdge(const Promise *from, const ModelAction *rmw);
/**
* @brief Adds an edge between objects
* @param from The edge comes from this object, of type U
* @return True, if new edge(s) are added; otherwise false
*/
-template <typename T, typename U>
-bool CycleGraph::addEdge(const T *from, const U *to)
+
+void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to)
+{
+ ASSERT(from);
+ ASSERT(to);
+
+ CycleNode *fromnode = getNode(from);
+ CycleNode *tonode = getNode(to);
+
+ addNodeEdge(fromnode, tonode, false);
+}
+
+void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to, bool forceedge)
{
ASSERT(from);
ASSERT(to);
CycleNode *fromnode = getNode(from);
CycleNode *tonode = getNode(to);
- return addNodeEdge(fromnode, tonode);
+ addNodeEdge(fromnode, tonode, forceedge);
}
-/* 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(const CycleNode *node, FILE *file, int label)
+static void print_node(FILE *file, const CycleNode *node, int label)
{
- modelclock_t idx;
- if (node->is_promise()) {
- const Promise *promise = node->getPromise();
- idx = promise->get_reader(0)->get_seq_number();
- fprintf(file, "P%u", idx);
- if (label) {
- int first = 1;
- fprintf(file, " [label=\"P%u, T", idx);
- for (unsigned int i = 0 ; i < model->get_num_threads(); 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();
- idx = act->get_seq_number();
- fprintf(file, "N%u", idx);
- if (label)
- fprintf(file, " [label=\"N%u, T%u\"]", idx, act->get_tid());
- }
+ 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);
+}
+
+void CycleGraph::dot_print_edge(FILE *file, const ModelAction *from, const ModelAction *to, const char *prop)
+{
+ CycleNode *fromnode = getNode(from);
+ CycleNode *tonode = getNode(to);
+
+ print_edge(file, fromnode, tonode, prop);
}
void CycleGraph::dumpNodes(FILE *file) const
{
- for (unsigned int i = 0; i < nodeList.size(); i++) {
+ for (unsigned int i = 0;i < nodeList.size();i++) {
CycleNode *n = nodeList[i];
- print_node(n, file, 1);
+ print_node(file, n, 1);
fprintf(file, ";\n");
- if (n->getRMW() != NULL) {
- print_node(n, file, 0);
- fprintf(file, " -> ");
- print_node(n->getRMW(), file, 0);
- fprintf(file, "[style=dotted];\n");
- }
- for (unsigned int j = 0; j < n->getNumEdges(); j++) {
- print_node(n, file, 0);
- fprintf(file, " -> ");
- print_node(n->getEdge(j), file, 0);
- 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);
- discovered->put(from, from);
- 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);
- }
- }
- }
- return false;
+ return to->cv->synchronized_since(from->action);
}
/**
- * 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
+ * Checks whether one ModelAction can reach another ModelAction
+ * @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
*/
-template <typename T, typename U>
-bool CycleGraph::checkReachable(const T *from, const U *to) const
+bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) const
{
CycleNode *fromnode = getNode_noCreate(from);
CycleNode *tonode = getNode_noCreate(to);
return checkReachable(fromnode, tonode);
}
-/* Instantiate three 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;
-
-/** @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();
- CycleNode *from = actionToNode.get(fromact);
-
- queue.push_back(from);
- discovered->put(from, from);
- while (!queue.empty()) {
- 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;
-
- 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);
- }
- }
- }
- return false;
-}
-
-void CycleGraph::startChanges()
-{
- ASSERT(rollbackvector.empty());
- ASSERT(rmwrollbackvector.empty());
- ASSERT(oldCycles == hasCycles);
-}
-
-/** Commit changes to the cyclegraph. */
-void CycleGraph::commitChanges()
-{
- rollbackvector.clear();
- rmwrollbackvector.clear();
- oldCycles = hasCycles;
-}
-
-/** Rollback changes to the previous commit. */
-void CycleGraph::rollbackChanges()
-{
- for (unsigned int i = 0; i < rollbackvector.size(); i++)
- rollbackvector[i]->removeEdge();
-
- for (unsigned int i = 0; i < rmwrollbackvector.size(); i++)
- rmwrollbackvector[i]->clearRMW();
-
- hasCycles = oldCycles;
- rollbackvector.clear();
- rmwrollbackvector.clear();
-}
-
-/** @returns whether a CycleGraph contains cycles. */
-bool CycleGraph::checkForCycles() const
-{
- return hasCycles;
-}
/**
* @brief Constructor for a CycleNode
*/
CycleNode::CycleNode(const ModelAction *act) :
action(act),
- promise(NULL),
- hasRMW(NULL)
-{
-}
-
-/**
- * @brief Constructor for a Promise CycleNode
- * @param promise The Promise which was generated
- */
-CycleNode::CycleNode(const Promise *promise) :
- action(NULL),
- promise(promise),
- hasRMW(NULL)
+ hasRMW(NULL),
+ cv(new ClockVector(NULL, act))
{
}
/**
* @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();
}
-CycleNode * CycleNode::getBackEdge(unsigned int i) const
-{
- return back_edges[i];
-}
-
-unsigned int CycleNode::getNumBackEdges() const
-{
- return back_edges.size();
-}
-
-/**
- * @brief Remove an element from a vector
- * @param v The vector
- * @param n The element to remove
- * @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)
-{
- for (unsigned int i = 0; i < v.size(); i++) {
- if (v[i] == n) {
- v.erase(v.begin() + i);
- return true;
- }
- }
- return false;
-}
-
/**
* @brief Remove a (forward) edge from this CycleNode
* @return The CycleNode which was popped, if one exists; otherwise NULL
CycleNode *ret = edges.back();
edges.pop_back();
- vector_remove_node(ret->back_edges, this);
- return ret;
-}
-
-/**
- * @brief Remove a (back) edge from this CycleNode
- * @return The CycleNode which was popped, if one exists; otherwise NULL
- */
-CycleNode * CycleNode::removeBackEdge()
-{
- if (back_edges.empty())
- return NULL;
-
- CycleNode *ret = back_edges.back();
- back_edges.pop_back();
- vector_remove_node(ret->edges, this);
return ret;
}
* @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)
+void CycleNode::addEdge(CycleNode *node)
{
- for (unsigned int i = 0; i < edges.size(); i++)
+ for (unsigned int i = 0;i < edges.size();i++)
if (edges[i] == node)
- return false;
+ return;
edges.push_back(node);
- node->back_edges.push_back(this);
- return true;
}
/** @returns the RMW CycleNode that reads from the current CycleNode */
hasRMW = node;
return false;
}
-
-/**
- * Convert a Promise CycleNode into a concrete-valued CycleNode. Should only be
- * used when there's no existing ModelAction CycleNode for this write.
- *
- * @param writer The ModelAction which wrote the future value represented by
- * this CycleNode
- */
-void CycleNode::resolvePromise(const ModelAction *writer)
-{
- ASSERT(is_promise());
- ASSERT(promise->is_compatible(writer));
- action = writer;
- promise = NULL;
- ASSERT(!is_promise());
-}