X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=cyclegraph.cc;h=aa3d24548a554ab039074282f5bab3246e3d3ccd;hp=b140ded1382c12cfc9fee46358bd36fc2720aa36;hb=e44b9753a9b616cba58c2fb0583b876e3d4006ae;hpb=ad9f8597027acf647e4fc3a0b22ac3312d291878

diff --git a/cyclegraph.cc b/cyclegraph.cc
index b140ded..aa3d245 100644
--- a/cyclegraph.cc
+++ b/cyclegraph.cc
@@ -1,9 +1,13 @@
 #include "cyclegraph.h"
 #include "action.h"
+#include "common.h"
 
 /** Initializes a CycleGraph object. */
 CycleGraph::CycleGraph() :
-	hasCycles(false)
+	hasCycles(false),
+	oldCycles(false),
+	hasRMWViolation(false),
+	oldRMWViolation(false)
 {
 }
 
@@ -21,6 +25,9 @@ CycleNode * CycleGraph::getNode(const ModelAction *action) {
 	if (node==NULL) {
 		node=new CycleNode(action);
 		actionToNode.put(action, node);
+#if SUPPORT_MOD_ORDER_DUMP
+		nodeList.push_back(node);
+#endif
 	}
 	return node;
 }
@@ -32,6 +39,10 @@ CycleNode * CycleGraph::getNode(const ModelAction *action) {
  * @param from The edge comes from this ModelAction
  */
 void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to) {
+	ASSERT(from);
+	ASSERT(to);
+	ASSERT(from != to);
+
 	CycleNode *fromnode=getNode(from);
 	CycleNode *tonode=getNode(to);
 
@@ -39,19 +50,28 @@ void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to) {
 		// Check for Cycles
 		hasCycles=checkReachable(tonode, 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
 
-	if (rmwnode!=NULL&&rmwnode!=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);
 		}
-		rmwnode->addEdge(tonode);
+
+		if (rmwnode->addEdge(tonode))
+			rollbackvector.push_back(rmwnode);
 	}
 }
 
@@ -61,26 +81,90 @@ void CycleGraph::addEdge(const ModelAction *from, const ModelAction *to) {
  *  action can read from a given write.
  */
 void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw) {
+	ASSERT(from);
+	ASSERT(rmw);
+	ASSERT(from != 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.*/
+	/* 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.
+	 */
 	std::vector<CycleNode *> * edges=fromnode->getEdges();
 	for(unsigned int i=0;i<edges->size();i++) {
 		CycleNode * tonode=(*edges)[i];
-		rmwnode->addEdge(tonode);
+		if (tonode!=rmwnode) {
+			if (rmwnode->addEdge(tonode))
+				rollbackvector.push_back(rmwnode);
+		}
+	}
+
+
+	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);
+}
 
-	fromnode->addEdge(rmwnode);
+#if SUPPORT_MOD_ORDER_DUMP
+void CycleGraph::dumpNodes(FILE *file) {
+  for(unsigned int i=0;i<nodeList.size();i++) {
+		CycleNode *cn=nodeList[i];
+		std::vector<CycleNode *> * edges=cn->getEdges();
+		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<edges->size();j++) {
+		  CycleNode *dst=(*edges)[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 one CycleNode can reach another.
@@ -89,8 +173,8 @@ void CycleGraph::addRMWEdge(const ModelAction *from, const ModelAction *rmw) {
  * @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;
+	std::vector<CycleNode *, ModelAlloc<CycleNode *> > queue;
+	HashTable<CycleNode *, CycleNode *, uintptr_t, 4, model_malloc, model_calloc, model_free> discovered;
 
 	queue.push_back(from);
 	discovered.put(from, from);
@@ -111,11 +195,46 @@ 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);
+}
+
+/** 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;
 }
 
+bool CycleGraph::checkForRMWViolation() {
+	return hasRMWViolation;
+}
+
 /**
  * Constructor for a CycleNode.
  * @param modelaction The ModelAction for this node
@@ -135,8 +254,12 @@ std::vector<CycleNode *> * CycleNode::getEdges() {
  * 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);
+	return true;
 }
 
 /** @returns the RMW CycleNode that reads from the current CycleNode */
@@ -151,7 +274,8 @@ CycleNode * CycleNode::getRMW() {
  * @see CycleGraph::addRMWEdge
  */
 bool CycleNode::setRMW(CycleNode *node) {
-	CycleNode * oldhasRMW=hasRMW;
+	if (hasRMW!=NULL)
+		return true;
 	hasRMW=node;
-	return (oldhasRMW!=NULL);
+	return false;
 }