X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=cyclegraph.cc;h=51066c94601fef25bf99e021a91183b66719ad08;hb=8ea66f246f18e3a92e279a9ba49c29beb2d8ef52;hp=f060a00e74362b6f9df99649ffd844f7e416d4b9;hpb=20926923f6de1790fdd368d5e7fa1738abe7b9a6;p=model-checker.git

diff --git a/cyclegraph.cc b/cyclegraph.cc
index f060a00..51066c9 100644
--- a/cyclegraph.cc
+++ b/cyclegraph.cc
@@ -1,49 +1,87 @@
 #include "cyclegraph.h"
 #include "action.h"
+#include "common.h"
+#include "promise.h"
+#include "model.h"
 
 /** Initializes a CycleGraph object. */
-CycleGraph::CycleGraph() {
-	hasCycles=false;
+CycleGraph::CycleGraph() :
+	discovered(new HashTable<CycleNode *, CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free>(16)),
+	hasCycles(false),
+	oldCycles(false),
+	hasRMWViolation(false),
+	oldRMWViolation(false)
+{
 }
 
-CycleGraph::~CycleGraph() {
+/** CycleGraph destructor */
+CycleGraph::~CycleGraph()
+{
 }
 
-/** Returns the CycleNode for a given ModelAction. */
-CycleNode * CycleGraph::getNode(const ModelAction * action) {
-	CycleNode *node=actionToNode.get(action);
-	if (node==NULL) {
-		node=new CycleNode(action);
+/**
+ * @brief Returns the CycleNode corresponding to a given 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);
+#if SUPPORT_MOD_ORDER_DUMP
+		nodeList.push_back(node);
+#endif
 	}
 	return node;
 }
 
 /**
- * Adds an edge between two ModelActions.  The ModelAction to happens after the
- * ModelAction from.
+ * 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 *to, const ModelAction *from) {
-	CycleNode *fromnode=getNode(from);
-	CycleNode *tonode=getNode(to);
+void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to)
+{
+	ASSERT(from);
+	ASSERT(to);
+
+	CycleNode *fromnode = getNode(from);
+	CycleNode *tonode = getNode(to);
 
+	if (!hasCycles) {
+		// Reflexive edges are cycles
+		hasCycles = (from == to);
+	}
 	if (!hasCycles) {
 		// Check for Cycles
-		hasCycles=checkReachable(tonode, fromnode);
+		hasCycles = checkReachable(tonode, fromnode);
 	}
-	fromnode->addEdge(tonode);
 
-	CycleNode * rmwnode=fromnode->getRMW();
+	if (fromnode->addEdge(tonode))
+		rollbackvector.push_back(fromnode);
 
-	//If the fromnode has a rmwnode that is not the tonode, we
-	//should add an edge between its rmwnode and the tonode
 
-	if (rmwnode!=NULL&&rmwnode!=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 (rmwnode != NULL && !to->is_rmw()) {
 		if (!hasCycles) {
 			// Check for Cycles
-			hasCycles=checkReachable(tonode, rmwnode);
+			hasCycles = checkReachable(tonode, rmwnode);
 		}
-		rmwnode->addEdge(tonode);
+
+		if (rmwnode->addEdge(tonode))
+			rollbackvector.push_back(rmwnode);
 	}
 }
 
@@ -52,45 +90,120 @@ void CycleGraph::addEdge(const ModelAction *to, const ModelAction *from) {
  *  can occur in between the rmw and the from action.  Only one RMW
  *  action can read from a given write.
  */
-void CycleGraph::addRMWEdge(const ModelAction *rmw, const ModelAction * from) {
-	CycleNode *fromnode=getNode(from);
-	CycleNode *rmwnode=getNode(rmw);
+void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw)
+{
+	ASSERT(from);
+	ASSERT(rmw);
+
+	CycleNode *fromnode = getNode(from);
+	CycleNode *rmwnode = getNode(rmw);
 
 	/* Two RMW actions cannot read from the same write. */
 	if (fromnode->setRMW(rmwnode)) {
-		hasCycles=true;
+		hasRMWViolation = true;
+	} else {
+		rmwrollbackvector.push_back(fromnode);
 	}
 
 	/* Transfer all outgoing edges from the from node to the rmw node */
-	/* This process cannot add a cycle because rmw should not have any
-		 incoming edges yet.*/
-	std::vector<CycleNode *> * edges=fromnode->getEdges();
-	for(unsigned int i=0;i<edges->size();i++) {
-		CycleNode * tonode=(*edges)[i];
-		rmwnode->addEdge(tonode);
+	/* This process should not add a cycle because either:
+	 * (1) The rmw should not have any incoming edges yet if it is the
+	 * new node or
+	 * (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++) {
+		CycleNode *tonode = fromnode->getEdge(i);
+		if (tonode != rmwnode) {
+			if (rmwnode->addEdge(tonode))
+				rollbackvector.push_back(rmwnode);
+		}
 	}
 
-	fromnode->addEdge(rmwnode);
+
+	if (!hasCycles) {
+		// Reflexive edges are cycles
+		hasCycles = (from == rmw);
+	}
+	if (!hasCycles) {
+		// With promises we could be setting up a cycle here if we aren't
+		// careful...avoid it..
+		hasCycles = checkReachable(rmwnode, fromnode);
+	}
+	if (fromnode->addEdge(rmwnode))
+		rollbackvector.push_back(fromnode);
 }
 
+#if SUPPORT_MOD_ORDER_DUMP
+void CycleGraph::dumpNodes(FILE *file)
+{
+	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());
+		}
+	}
+}
+
+void CycleGraph::dumpGraphToFile(const char *filename)
+{
+	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 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)
+{
+	CycleNode *fromnode = actionToNode.get(from);
+	CycleNode *tonode = actionToNode.get(to);
+
+	if (!fromnode || !tonode)
+		return false;
+
+	return checkReachable(fromnode, tonode);
+}
 
-/** Checks whether the first CycleNode can reach the second one. */
-bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) {
-	std::vector<CycleNode *> queue;
-	HashTable<CycleNode *, CycleNode *, uintptr_t, 4> discovered;
+/**
+ * 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 *, ModelAlloc<CycleNode *> > queue;
+	discovered->reset();
 
 	queue.push_back(from);
-	discovered.put(from, from);
-	while(!queue.empty()) {
-		CycleNode * node=queue.back();
+	discovered->put(from, from);
+	while (!queue.empty()) {
+		CycleNode *node = queue.back();
 		queue.pop_back();
-		if (node==to)
+		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);
+		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);
 			}
 		}
@@ -98,35 +211,129 @@ bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) {
 	return false;
 }
 
-/** Returns whether a CycleGraph contains cycles. */
+bool CycleGraph::checkPromise(const ModelAction *fromact, Promise *promise)
+{
+	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 (promise->increment_threads(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.size() == 0);
+	ASSERT(rmwrollbackvector.size() == 0);
+	ASSERT(oldCycles == hasCycles);
+	ASSERT(oldRMWViolation == hasRMWViolation);
+}
+
+/** Commit changes to the cyclegraph. */
+void CycleGraph::commitChanges()
+{
+	rollbackvector.resize(0);
+	rmwrollbackvector.resize(0);
+	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 < rmwrollbackvector.size(); i++) {
+		rmwrollbackvector[i]->clearRMW();
+	}
+
+	hasCycles = oldCycles;
+	hasRMWViolation = oldRMWViolation;
+	rollbackvector.resize(0);
+	rmwrollbackvector.resize(0);
+}
+
+/** @returns whether a CycleGraph contains cycles. */
 bool CycleGraph::checkForCycles() {
 	return hasCycles;
 }
 
-/** Constructor for a CycleNode. */
-CycleNode::CycleNode(const ModelAction *modelaction) {
-	action=modelaction;
-	hasRMW=NULL;
+bool CycleGraph::checkForRMWViolation() {
+	return hasRMWViolation;
+}
+
+/**
+ * Constructor for a CycleNode.
+ * @param modelaction The ModelAction for this node
+ */
+CycleNode::CycleNode(const ModelAction *modelaction) :
+	action(modelaction),
+	hasRMW(NULL)
+{
+}
+
+/**
+ * @param i The index of the edge to return
+ * @returns The a CycleNode edge indexed by i
+ */
+CycleNode * CycleNode::getEdge(unsigned int i) const
+{
+	return edges[i];
 }
 
-/** Returns a vector of the edges from a CycleNode. */
-std::vector<CycleNode *> * CycleNode::getEdges() {
-	return &edges;
+/** @returns The number of edges leaving this CycleNode */
+unsigned int CycleNode::getNumEdges() const
+{
+	return edges.size();
 }
 
-/** Adds an edge to a CycleNode. */
-void CycleNode::addEdge(CycleNode * node) {
+/**
+ * Adds an edge from this CycleNode to another CycleNode.
+ * @param node The node to which we add a directed edge
+ */
+bool CycleNode::addEdge(CycleNode *node)
+{
+	for (unsigned int i = 0; i < edges.size(); i++)
+		if (edges[i] == node)
+			return false;
 	edges.push_back(node);
+	return true;
 }
 
-/** Get the RMW CycleNode that reads from the current CycleNode. */
-CycleNode* CycleNode::getRMW() {
+/** @returns the RMW CycleNode that reads from the current CycleNode */
+CycleNode * CycleNode::getRMW() const
+{
 	return hasRMW;
 }
 
-/** Set a RMW action node that reads from the current CycleNode. */
-bool CycleNode::setRMW(CycleNode * node) {
-	CycleNode * oldhasRMW=hasRMW;
-	hasRMW=node;
-	return (oldhasRMW!=NULL);
+/**
+ * Set a RMW action node that reads from the current CycleNode.
+ * @param node The RMW that reads from the current node
+ * @return True, if this node already was read by another RMW; false otherwise
+ * @see CycleGraph::addRMWEdge
+ */
+bool CycleNode::setRMW(CycleNode *node)
+{
+	if (hasRMW != NULL)
+		return true;
+	hasRMW = node;
+	return false;
 }