#include "cyclegraph.h"
#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),
- hasRMWViolation(false),
- oldRMWViolation(false)
+ oldCycles(false)
{
}
/** CycleGraph destructor */
CycleGraph::~CycleGraph()
{
+ delete queue;
delete discovered;
}
#endif
}
+/** @return The corresponding CycleNode, if exists; otherwise NULL */
+CycleNode * CycleGraph::getNode_noCreate(const ModelAction *act) const
+{
+ return actionToNode.get(act);
+}
+
/**
* @brief Returns the CycleNode corresponding to a given ModelAction
+ *
+ * Gets (or creates, if none exist) a CycleNode corresponding to a ModelAction
+ *
* @param action The ModelAction to find a node for
* @return The CycleNode paired with this action
*/
CycleNode * CycleGraph::getNode(const ModelAction *action)
{
- CycleNode *node = actionToNode.get(action);
+ CycleNode *node = getNode_noCreate(action);
if (node == NULL) {
node = new CycleNode(action);
putNode(action, node);
return node;
}
-/**
- * Adds an edge between two ModelActions. The ModelAction @a to is ordered
- * after the ModelAction @a from.
- * @param to The edge points to this ModelAction
- * @param from The edge comes from this ModelAction
- */
-void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to)
-{
- ASSERT(from);
- ASSERT(to);
-
- CycleNode *fromnode = getNode(from);
- CycleNode *tonode = getNode(to);
-
- 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
+ * @return True, if new edge(s) are added; otherwise false
*/
-void CycleGraph::addEdge(CycleNode *fromnode, CycleNode *tonode)
+bool CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode)
{
- if (!hasCycles)
- hasCycles = checkReachable(tonode, fromnode);
-
- if (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);
+ if (rmwnode != tonode) {
+ if (rmwnode->addEdge(tonode)) {
+ if (!hasCycles)
+ hasCycles = checkReachable(tonode, rmwnode);
+
+ rollbackvector.push_back(rmwnode);
+ }
+ }
}
+ return true;
}
/**
* @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.
+ * the ModelAction/Promise 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
+ * @param from The edge comes from this ModelAction/Promise
* @param rmw The edge points to this ModelAction; this action must read from
- * ModelAction from
+ * the ModelAction/Promise from
*/
-void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw)
+template <typename T>
+void CycleGraph::addRMWEdge(const T *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)) {
- 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:
}
}
- addEdge(fromnode, rmwnode);
+ addNodeEdge(fromnode, rmwnode);
}
+/* Instantiate two forms of CycleGraph::addRMWEdge */
+template void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw);
+
+/**
+ * @brief Adds an edge between objects
+ *
+ * This function will add an edge between any two objects which can be
+ * associated with a CycleNode. That is, if they have a CycleGraph::getNode
+ * implementation.
+ *
+ * The object to is ordered after the object from.
+ *
+ * @param to The edge points to this object, of type T
+ * @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)
+{
+ ASSERT(from);
+ ASSERT(to);
+
+ CycleNode *fromnode = getNode(from);
+ CycleNode *tonode = getNode(to);
+
+ return addNodeEdge(fromnode, tonode);
+}
+/* Instantiate four forms of CycleGraph::addEdge */
+template bool CycleGraph::addEdge(const ModelAction *from, const ModelAction *to);
#if SUPPORT_MOD_ORDER_DUMP
+
+static void print_node(FILE *file, const CycleNode *node, int label)
+{
+ 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 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);
}
}
}
#endif
-/**
- * Checks whether one ModelAction can reach another.
- * @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
- */
-bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) const
-{
- CycleNode *fromnode = actionToNode.get(from);
- CycleNode *tonode = actionToNode.get(to);
-
- if (!fromnode || !tonode)
- return false;
-
- return checkReachable(fromnode, tonode);
-}
-
/**
* Checks whether one CycleNode can reach another.
* @param from The CycleNode from which to begin exploration
*/
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 false;
}
-bool CycleGraph::checkPromise(const ModelAction *fromact, Promise *promise) const
+/**
+ * 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, typename U>
+bool CycleGraph::checkReachable(const T *from, const U *to) 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();
+ CycleNode *fromnode = getNode_noCreate(from);
+ CycleNode *tonode = getNode_noCreate(to);
- if (promise->eliminate_thread(node->getAction()->get_tid())) {
- return true;
- }
+ if (!fromnode || !tonode)
+ return false;
- 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 checkReachable(fromnode, tonode);
}
+/* Instantiate four forms of CycleGraph::checkReachable */
+template bool CycleGraph::checkReachable(const ModelAction *from,
+ const ModelAction *to) const;
+/** @brief Begin a new sequence of graph additions which can be rolled back */
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++) {
- rollbackvector[i]->popEdge();
- }
+ for (unsigned int i = 0; i < rollbackvector.size(); i++)
+ rollbackvector[i]->removeEdge();
- 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. */
return hasCycles;
}
-bool CycleGraph::checkForRMWViolation() const
-{
- return hasRMWViolation;
-}
-
/**
* @brief Constructor for a CycleNode
* @param act The ModelAction for this node
/**
* @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();
}
+/**
+ * @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(SnapVector<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 * CycleNode::removeEdge()
+{
+ if (edges.empty())
+ return 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;
+}
+
/**
* Adds an edge from this CycleNode to another CycleNode.
* @param node The node to which we add a directed edge