#include "cyclegraph.h"
#include "action.h"
#include "common.h"
+#include "threads-model.h"
+#include "clockvector.h"
/** Initializes a CycleGraph object. */
CycleGraph::CycleGraph() :
- hasCycles(false),
- oldCycles(false),
- hasRMWViolation(false),
- oldRMWViolation(false)
+ queue(new SnapVector<const CycleNode *>())
{
}
/** CycleGraph destructor */
-CycleGraph::~CycleGraph() {
+CycleGraph::~CycleGraph()
+{
+ delete queue;
+}
+
+/**
+ * Add a CycleNode to the graph, corresponding to a store ModelAction
+ * @param act The write action that should be added
+ * @param node The CycleNode that corresponds to the store
+ */
+void CycleGraph::putNode(const ModelAction *act, CycleNode *node)
+{
+ actionToNode.put(act, node);
+#if SUPPORT_MOD_ORDER_DUMP
+ nodeList.push_back(node);
+#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);
- if (node==NULL) {
- node=new CycleNode(action);
- actionToNode.put(action, node);
+CycleNode * CycleGraph::getNode(const ModelAction *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
+ * 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(const ModelAction *from, const ModelAction *to) {
- ASSERT(from);
- ASSERT(to);
-
- CycleNode *fromnode=getNode(from);
- CycleNode *tonode=getNode(to);
-
- if (!hasCycles) {
- // Check for Cycles
- hasCycles=checkReachable(tonode, fromnode);
+void CycleGraph::addNodeEdge(CycleNode *fromnode, CycleNode *tonode, bool forceedge)
+{
+ //quick check whether edge is redundant
+ if (checkReachable(fromnode, tonode) && !forceedge) {
+ return;
}
- rollbackvector.push_back(fromnode);
- fromnode->addEdge(tonode);
-
- CycleNode * rmwnode=fromnode->getRMW();
-
- //If the fromnode has a rmwnode that is not the tonode, we
- //should add an edge between its rmwnode and the tonode
-
- //If tonode is also a rmw, don't do this check as the execution is
- //doomed and we'll catch the problem elsewhere, but we want to allow
- //for the possibility of sending to's write value to rmwnode
+ /*
+ * If the fromnode has a rmwnode, we should
+ * follow its RMW chain to add an edge at the end.
+ */
+ while (fromnode->getRMW()) {
+ CycleNode *nextnode = fromnode->getRMW();
+ if (nextnode == tonode)
+ break;
+ fromnode = nextnode;
+ }
- if (rmwnode!=NULL&&!to->is_rmw()) {
- if (!hasCycles) {
- // Check for Cycles
- hasCycles=checkReachable(tonode, rmwnode);
+ 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);
+ }
}
- rollbackvector.push_back(rmwnode);
- rmwnode->addEdge(tonode);
}
}
-/** Handles special case of a RMW action. 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. Only one RMW
- * action can read from a given write.
+/**
+ * @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:
+ * -# 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 rmw The edge points to this ModelAction; this action must read from
+ * the ModelAction from
*/
-void CycleGraph::addRMWEdge(const ModelAction *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);
+ 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 {
- 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.
*/
- std::vector<CycleNode *> * edges=fromnode->getEdges();
- for(unsigned int i=0;i<edges->size();i++) {
- CycleNode * tonode=(*edges)[i];
- if (tonode!=rmwnode) {
- rollbackvector.push_back(rmwnode);
+ for (unsigned int i = 0;i < fromnode->getNumEdges();i++) {
+ CycleNode *tonode = fromnode->getEdge(i);
+ if (tonode != rmwnode) {
rmwnode->addEdge(tonode);
}
}
- rollbackvector.push_back(fromnode);
+ fromnode->edges.clear();
- if (!hasCycles) {
- // With promises we could be setting up a cycle here if we aren't
- // careful...avoid it..
- hasCycles=checkReachable(rmwnode, fromnode);
- }
- fromnode->addEdge(rmwnode);
+ addNodeEdge(fromnode, rmwnode, true);
}
/**
- * 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
+ * @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
*/
-bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) {
- CycleNode *fromnode = actionToNode.get(from);
- CycleNode *tonode = actionToNode.get(to);
- if (!fromnode || !tonode)
- return false;
+void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to)
+{
+ ASSERT(from);
+ ASSERT(to);
- return checkReachable(fromnode, tonode);
+ 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);
+
+ addNodeEdge(fromnode, tonode, forceedge);
+}
+
+#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);
+}
+
+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++) {
+ 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);
+ }
+}
+
+void CycleGraph::dumpGraphToFile(const char *filename) const
+{
+ char buffer[200];
+ sprintf(buffer, "%s.dot", filename);
+ FILE *file = fopen(buffer, "w");
+ fprintf(file, "digraph %s {\n", filename);
+ dumpNodes(file);
+ fprintf(file, "}\n");
+ fclose(file);
+}
+#endif
+
/**
* Checks whether one CycleNode can reach another.
* @param from The CycleNode from which to begin exploration
* @param to The CycleNode to reach
* @return True, @a from can reach @a to; otherwise, false
*/
-bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) {
- std::vector<CycleNode *> queue;
- HashTable<CycleNode *, CycleNode *, uintptr_t, 4> discovered;
-
- queue.push_back(from);
- discovered.put(from, from);
- while(!queue.empty()) {
- CycleNode * node=queue.back();
- queue.pop_back();
- if (node==to)
- return true;
-
- for(unsigned int i=0;i<node->getEdges()->size();i++) {
- CycleNode *next=(*node->getEdges())[i];
- if (!discovered.contains(next)) {
- discovered.put(next,next);
- queue.push_back(next);
- }
- }
- }
- return false;
-}
-
-void CycleGraph::startChanges() {
- ASSERT(rollbackvector.size()==0);
- ASSERT(rmwrollbackvector.size()==0);
- ASSERT(oldCycles==hasCycles);
- ASSERT(oldRMWViolation==hasRMWViolation);
+bool CycleGraph::checkReachable(const CycleNode *from, const CycleNode *to) const
+{
+ return to->cv->synchronized_since(from->action);
}
-/** Commit changes to the cyclegraph. */
-void CycleGraph::commitChanges() {
- rollbackvector.resize(0);
- rmwrollbackvector.resize(0);
- oldCycles=hasCycles;
- oldRMWViolation=hasRMWViolation;
-}
+/**
+ * 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
+ */
+bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) const
+{
+ CycleNode *fromnode = getNode_noCreate(from);
+ CycleNode *tonode = getNode_noCreate(to);
-/** Rollback changes to the previous commit. */
-void CycleGraph::rollbackChanges() {
- for (unsigned int i = 0; i < rollbackvector.size(); i++) {
- rollbackvector[i]->popEdge();
- }
+ if (!fromnode || !tonode)
+ return false;
- for (unsigned int i = 0; i < rmwrollbackvector.size(); i++) {
- rmwrollbackvector[i]->clearRMW();
- }
+ return checkReachable(fromnode, tonode);
+}
- hasCycles = oldCycles;
- hasRMWViolation = oldRMWViolation;
- rollbackvector.resize(0);
- rmwrollbackvector.resize(0);
+/**
+ * @brief Constructor for a CycleNode
+ * @param act The ModelAction for this node
+ */
+CycleNode::CycleNode(const ModelAction *act) :
+ action(act),
+ hasRMW(NULL),
+ cv(new ClockVector(NULL, act))
+{
}
-/** @returns whether a CycleGraph contains cycles. */
-bool CycleGraph::checkForCycles() {
- return hasCycles;
+/**
+ * @param i The index of the edge to return
+ * @returns The CycleNode edge indexed by i
+ */
+CycleNode * CycleNode::getEdge(unsigned int i) const
+{
+ return edges[i];
}
-bool CycleGraph::checkForRMWViolation() {
- return hasRMWViolation;
+/** @returns The number of edges leaving this CycleNode */
+unsigned int CycleNode::getNumEdges() const
+{
+ return edges.size();
}
/**
- * Constructor for a CycleNode.
- * @param modelaction The ModelAction for this node
+ * @brief Remove a (forward) edge from this CycleNode
+ * @return The CycleNode which was popped, if one exists; otherwise NULL
*/
-CycleNode::CycleNode(const ModelAction *modelaction) :
- action(modelaction),
- hasRMW(NULL)
+CycleNode * CycleNode::removeEdge()
{
-}
+ if (edges.empty())
+ return NULL;
-/** @returns a vector of the edges from a CycleNode. */
-std::vector<CycleNode *> * CycleNode::getEdges() {
- return &edges;
+ CycleNode *ret = edges.back();
+ edges.pop_back();
+ return ret;
}
/**
* Adds an edge from this CycleNode to another CycleNode.
* @param node The node to which we add a directed edge
+ * @return True if this edge is a new edge; false otherwise
*/
-void CycleNode::addEdge(CycleNode *node) {
+void CycleNode::addEdge(CycleNode *node)
+{
+ for (unsigned int i = 0;i < edges.size();i++)
+ if (edges[i] == node)
+ return;
edges.push_back(node);
}
/** @returns the RMW CycleNode that reads from the current CycleNode */
-CycleNode * CycleNode::getRMW() {
+CycleNode * CycleNode::getRMW() const
+{
return hasRMW;
}
* @return True, if this node already was read by another RMW; false otherwise
* @see CycleGraph::addRMWEdge
*/
-bool CycleNode::setRMW(CycleNode *node) {
- if (hasRMW!=NULL)
+bool CycleNode::setRMW(CycleNode *node)
+{
+ if (hasRMW != NULL)
return true;
- hasRMW=node;
+ hasRMW = node;
return false;
}