X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=cyclegraph.cc;h=3949b6ec86d885056282a0b84d0975267da13cdd;hb=d70f6f259c9850e5fceb527e3a9541c440c0146b;hp=62330624d6f08a233292ddfee1269380e8869beb;hpb=c4497f6168d1af560d9305337139d35bcd4ee9bb;p=model-checker.git

diff --git a/cyclegraph.cc b/cyclegraph.cc
index 6233062..3949b6e 100644
--- a/cyclegraph.cc
+++ b/cyclegraph.cc
@@ -1,9 +1,12 @@
 #include "cyclegraph.h"
 #include "action.h"
 #include "common.h"
+#include "promise.h"
+#include "model.h"
 
 /** Initializes a CycleGraph object. */
 CycleGraph::CycleGraph() :
+	discovered(new HashTable<CycleNode *, CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free>(16)),
 	hasCycles(false),
 	oldCycles(false),
 	hasRMWViolation(false),
@@ -12,7 +15,22 @@ CycleGraph::CycleGraph() :
 }
 
 /** CycleGraph destructor */
-CycleGraph::~CycleGraph() {
+CycleGraph::~CycleGraph()
+{
+	delete discovered;
+}
+
+/**
+ * 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
 }
 
 /**
@@ -20,11 +38,12 @@ CycleGraph::~CycleGraph() {
  * @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 = actionToNode.get(action);
+	if (node == NULL) {
+		node = new CycleNode(action);
+		putNode(action, node);
 	}
 	return node;
 }
@@ -35,33 +54,45 @@ CycleNode * CycleGraph::getNode(const ModelAction *action) {
  * @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) {
+void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to)
+{
 	ASSERT(from);
 	ASSERT(to);
 
-	CycleNode *fromnode=getNode(from);
-	CycleNode *tonode=getNode(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);
 	}
 
-	rollbackvector.push_back(fromnode);
-	fromnode->addEdge(tonode);
+	if (fromnode->addEdge(tonode))
+		rollbackvector.push_back(fromnode);
 
-	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
+	CycleNode *rmwnode = fromnode->getRMW();
 
-	if (rmwnode!=NULL&&rmwnode!=tonode) {
+	/*
+	 * 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);
 		}
-		rollbackvector.push_back(rmwnode);
-		rmwnode->addEdge(tonode);
+
+		if (rmwnode->addEdge(tonode))
+			rollbackvector.push_back(rmwnode);
 	}
 }
 
@@ -70,50 +101,88 @@ void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to) {
  *  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 *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);
 
 	/* Two RMW actions cannot read from the same write. */
 	if (fromnode->setRMW(rmwnode)) {
-		hasRMWViolation=true;
+		hasRMWViolation = 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: 
+	/* 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 
+	 * (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];
-		rollbackvector.push_back(rmwnode);
-		rmwnode->addEdge(tonode);
+	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);
+		}
 	}
-	rollbackvector.push_back(fromnode);
 
+
+	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);
+		hasCycles = checkReachable(rmwnode, fromnode);
+	}
+	if (fromnode->addEdge(rmwnode))
+		rollbackvector.push_back(fromnode);
+}
+
+#if SUPPORT_MOD_ORDER_DUMP
+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());
+		}
 	}
-	fromnode->addEdge(rmwnode);
 }
 
+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 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) {
+bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to) const
+{
 	CycleNode *fromnode = actionToNode.get(from);
 	CycleNode *tonode = actionToNode.get(to);
 
@@ -129,22 +198,23 @@ bool CycleGraph::checkReachable(const ModelAction *from, const ModelAction *to)
  * @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;
+bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) const
+{
+	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);
 			}
 		}
@@ -152,23 +222,53 @@ bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) {
 	return false;
 }
 
-void CycleGraph::startChanges() {
-	ASSERT(rollbackvector.size()==0);
-	ASSERT(rmwrollbackvector.size()==0);
-	ASSERT(oldCycles==hasCycles);
-	ASSERT(oldRMWViolation==hasRMWViolation);
+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 (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() {
+void CycleGraph::commitChanges()
+{
 	rollbackvector.resize(0);
 	rmwrollbackvector.resize(0);
-	oldCycles=hasCycles;
-	oldRMWViolation=hasRMWViolation;
+	oldCycles = hasCycles;
+	oldRMWViolation = hasRMWViolation;
 }
 
 /** Rollback changes to the previous commit. */
-void CycleGraph::rollbackChanges() {
+void CycleGraph::rollbackChanges()
+{
 	for (unsigned int i = 0; i < rollbackvector.size(); i++) {
 		rollbackvector[i]->popEdge();
 	}
@@ -184,39 +284,68 @@ void CycleGraph::rollbackChanges() {
 }
 
 /** @returns whether a CycleGraph contains cycles. */
-bool CycleGraph::checkForCycles() {
+bool CycleGraph::checkForCycles() const
+{
 	return hasCycles;
 }
 
-bool CycleGraph::checkForRMWViolation() {
+bool CycleGraph::checkForRMWViolation() const
+{
 	return hasRMWViolation;
 }
 
 /**
- * Constructor for a CycleNode.
- * @param modelaction The ModelAction for this node
+ * @brief Constructor for a CycleNode
+ * @param act The ModelAction for this node
  */
-CycleNode::CycleNode(const ModelAction *modelaction) :
-	action(modelaction),
+CycleNode::CycleNode(const ModelAction *act) :
+	action(act),
 	hasRMW(NULL)
 {
 }
 
-/** @returns a vector of the edges from a CycleNode. */
-std::vector<CycleNode *> * CycleNode::getEdges() {
-	return &edges;
+/**
+ * @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 The number of edges leaving this CycleNode */
+unsigned int CycleNode::getNumEdges() const
+{
+	return edges.size();
+}
+
+CycleNode * CycleNode::getBackEdge(unsigned int i) const
+{
+	return back_edges[i];
+}
+
+unsigned int CycleNode::getNumBackEdges() const
+{
+	return back_edges.size();
 }
 
 /**
  * Adds an edge from this CycleNode to another CycleNode.
  * @param node The node to which we add a directed edge
  */
-void CycleNode::addEdge(CycleNode *node) {
+bool CycleNode::addEdge(CycleNode *node)
+{
+	for (unsigned int i = 0; i < edges.size(); i++)
+		if (edges[i] == node)
+			return false;
 	edges.push_back(node);
+	node->back_edges.push_back(this);
+	return true;
 }
 
 /** @returns the RMW CycleNode that reads from the current CycleNode */
-CycleNode * CycleNode::getRMW() {
+CycleNode * CycleNode::getRMW() const
+{
 	return hasRMW;
 }
 
@@ -226,9 +355,10 @@ CycleNode * CycleNode::getRMW() {
  * @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;
 }