**/
public class ConflictTracker extends ListenerAdapter {
-
private final PrintWriter out;
private final HashSet<String> conflictSet = new HashSet<String>(); // Variables we want to track
private final HashSet<String> appSet = new HashSet<String>(); // Apps we want to find their conflicts
private final HashSet<String> manualSet = new HashSet<String>(); // Writer classes with manual inputs to detect direct-direct(No Conflict) interactions
private final HashMap<Integer, Node> nodes = new HashMap<Integer, Node>(); // Nodes of a graph
- private HashSet<NameValuePair> tempSetSet = new HashSet<NameValuePair>();
+ private ArrayList<NameValuePair> tempSetSet = new ArrayList<NameValuePair>();
private long timeout;
private long startTime;
private Node parentNode = new Node(-2);
private int depth;
private int id;
private boolean conflictFound = false;
- private boolean isSet = false;
private boolean manual = false;
-
+
+ private final String SET_LOCATION_METHOD = "setLocationMode";
+ private final String LOCATION_VAR = "locationMode";
public ConflictTracker(Config config, JPF jpf) {
out = new PrintWriter(System.out, true);
boolean propagateTheChange(Node currentNode) {
HashSet<Node> changed = new HashSet<Node>(currentNode.getSuccessors());
+ HashMap<Node, HashSet<Node>> parentQueueMap = new HashMap<Node, HashSet<Node>>();
+ HashSet<Node> parents = new HashSet<Node>();
+ parents.add(currentNode);
+
+ for (Node node : currentNode.getSuccessors()) {
+ parentQueueMap.put(node, parents);
+ }
while(!changed.isEmpty()) {
- // Get the first element of HashSet and remove it from the changed set
- Node nodeToProcess = changed.iterator().next();
- changed.remove(nodeToProcess);
-
- // Update the sets, store the outSet to temp before its changes
- boolean isChanged = updateSets(nodeToProcess);
-
- // Check for a conflict
- if (checkForConflict(nodeToProcess))
- return true;
-
- // Checking if the out set has changed or not(Add its successors to the change list!)
- if (isChanged) {
- for (Node i : nodeToProcess.getSuccessors()) {
- if (!changed.contains(i))
- changed.add(i);
+ // Get the first element of the changed set and remove it
+ Node nodeToProcess = changed.iterator().next();
+ changed.remove(nodeToProcess);
+
+ // Update the changed parents
+ parents = parentQueueMap.get(nodeToProcess);
+ boolean isChanged = false;
+
+ for (Node node : parents) {
+ // Update the edge
+ isChanged |= updateTheOutSet(node, nodeToProcess);
+ }
+
+ // Check for a conflict if the outSet of nodeToProcess is changed
+ if (isChanged) {
+ for (Node node : nodeToProcess.getSuccessors()) {
+ HashMap<Transition, ArrayList<NameValuePair>> setSets = nodeToProcess.getOutgoingEdges().get(node).getSetSetMap();
+ for (Map.Entry mapElement : setSets.entrySet()) {
+ Transition transition = (Transition)mapElement.getKey();
+ if (checkForConflict(nodeToProcess, node, transition))
+ return true;
+ }
}
}
- }
- return false;
+ // Update the parents list for the successors of the current node
+ parents = new HashSet<Node>();
+ parents.add(nodeToProcess);
+
+ // Checking if the out set has changed or not(Add its successors to the change list!)
+ if (isChanged) {
+ for (Node i : nodeToProcess.getSuccessors()) {
+ if (!changed.contains(i))
+ changed.add(i);
+
+ // Update the list of updated parents for the current node
+ if (parentQueueMap.containsKey(i))
+ parentQueueMap.get(i).add(nodeToProcess);
+ else
+ parentQueueMap.put(i, parents);
+ }
+ }
+ }
+
+ return false;
}
- boolean setOutSet(Node currentNode) {
- Integer prevSize = currentNode.getOutSet().size();
+ String createErrorMessage(NameValuePair pair, HashMap<String, String> valueMap, HashMap<String, Integer> writerMap) {
+ String message = "Conflict found between the two apps. App"+pair.getAppNum()+
+ " has written the value: "+pair.getValue()+
+ " to the variable: "+pair.getVarName()+" while App"
+ +writerMap.get(pair.getVarName())+" is overwriting the value: "
+ +valueMap.get(pair.getVarName())+" to the same variable!";
+ System.out.println(message);
+ return message;
+ }
- // Update based on setSet
- for (NameValuePair i : currentNode.getSetSet()) {
- if (currentNode.getOutSet().contains(i))
- currentNode.getOutSet().remove(i);
- currentNode.getOutSet().add(i);
+ boolean checkForConflict(Node parentNode, Node currentNode, Transition currentTransition) {
+ ArrayList<NameValuePair> setSet = parentNode.getOutgoingEdges().get(currentNode).getSetSetMap().get(currentTransition);
+ HashMap<String, String> valueMap = new HashMap<String, String>(); // HashMap from varName to value
+ HashMap<String, Integer> writerMap = new HashMap<String, Integer>(); // HashMap from varName to appNum
+
+ // Update the valueMap and writerMap + check for conflict between the elements of setSet
+ for (int i = 0;i < setSet.size();i++) {
+ NameValuePair nameValuePair = setSet.get(i);
+ String varName = nameValuePair.getVarName();
+ String value = nameValuePair.getValue();
+ Integer appNum = nameValuePair.getAppNum();
+
+ if (valueMap.containsKey(varName)) {
+ // Check if we have a same writer
+ if (!writerMap.get(varName).equals(appNum)) {
+ // Check if we have a conflict or not
+ if (!valueMap.get(varName).equals(value)) {
+ errorMessage = createErrorMessage(nameValuePair, valueMap, writerMap);
+ return true;
+ } else { // We have two writers writing the same value
+ writerMap.put(varName, 3); // 3 represents both apps
+ }
+ } else {
+ // Check if we have more than one value with the same writer
+ if (!valueMap.get(varName).equals(value)) {
+ // We have one writer writing more than one value in a same event
+ valueMap.put(varName, "twoValue");
+ }
+ }
+ } else {
+ valueMap.put(varName, value);
+ writerMap.put(varName, appNum);
+ }
}
- // Add all the inSet
- currentNode.getOutSet().addAll(currentNode.getInSet());
+ // Check for conflict between outSet and this transition setSet
+ for (NameValuePair i : currentNode.getOutSet()) {
+ if (valueMap.containsKey(i.getVarName())) {
+ String value = valueMap.get(i.getVarName());
+ Integer writer = writerMap.get(i.getVarName());
+ if ((value != null)&&(writer != null)) {
+ if (!value.equals(i.getValue())&&!writer.equals(i.getAppNum())) { // We have different values and different writers
+ errorMessage = createErrorMessage(i, valueMap, writerMap);
+ return true;
+ }
+ }
+ }
+ }
- // Check if the outSet is changed
- if (!prevSize.equals(currentNode.getOutSet().size()))
- return true;
-
- return false;
+ return false;
}
- void setInSet(Node currentNode) {
- for (Node i : currentNode.getPredecessors()) {
- currentNode.getInSet().addAll(i.getOutSet());
- }
- }
+ boolean updateTheOutSet(Node parentNode, Node currentNode) {
+ HashMap<Transition, ArrayList<NameValuePair>> setSet = parentNode.getOutgoingEdges().get(currentNode).getSetSetMap();
+ HashSet<String> updatedVarNames = new HashSet<String>();
+ Edge currentEdge = parentNode.getOutgoingEdges().get(currentNode);
+ HashMap<String, Integer> lastWriter = currentEdge.getLastWriter();
+ HashMap<String, String> lastValue = currentEdge.getLastValue();
+ boolean isChanged = false;
- boolean checkForConflict(Node currentNode) {
- HashMap<String, String> valueMap = new HashMap<String, String>(); // HashMap from varName to value
- HashMap<String, Integer> writerMap = new HashMap<String, Integer>(); // HashMap from varName to appNum
+ for (Map.Entry mapElement : setSet.entrySet()) {
+ ArrayList<NameValuePair> value = (ArrayList<NameValuePair>)mapElement.getValue();
+
+ for (int i = 0;i < value.size();i++) {
+ updatedVarNames.add(value.get(i).getVarName());
+ }
+ }
- for (NameValuePair i : currentNode.getSetSet()) {
- if (i.getIsManual()) // Manual input: we have no conflict
- continue;
- valueMap.put(i.getVarName(), i.getValue());
- if (writerMap.containsKey(i.getVarName()))
- writerMap.put(i.getVarName(), i.getAppNum()+writerMap.get(i.getVarName())); // We have two writers?
- else
- writerMap.put(i.getVarName(), i.getAppNum());
+ for (NameValuePair i : parentNode.getOutSet()) {
+ if (!updatedVarNames.contains(i.getVarName()))
+ isChanged |= currentNode.getOutSet().add(i);
}
- // Comparing the inSet and setSet to find the conflict
- for (NameValuePair i : currentNode.getInSet()) {
- if (valueMap.containsKey(i.getVarName())) {
- if (!(valueMap.get(i.getVarName()).equals(i.getValue()))) // We have different values
- if (!(writerMap.get(i.getVarName()).equals(i.getAppNum()))) {// We have different writers
- errorMessage = "Conflict found between the two apps. App"+i.getAppNum()+" has written the value: "+i.getValue()+
- " to the variable: "+i.getVarName()+" while App"+writerMap.get(i.getVarName())+" is overwriting the value: "
- +valueMap.get(i.getVarName())+" to the same variable!";
- return true;
- }
- }
- }
- return false;
+ for (Map.Entry mapElement : setSet.entrySet()) {
+ ArrayList<NameValuePair> value = (ArrayList<NameValuePair>)mapElement.getValue();
+
+ for (int i = 0;i < value.size();i++) {
+ if (value.get(i).getAppNum().equals(lastWriter.get(value.get(i).getVarName()))
+ && value.get(i).getValue().equals(lastValue.get(value.get(i).getVarName()))) {
+ isChanged |= currentNode.getOutSet().add(value.get(i));
+ }
+ }
+ }
+
+ return isChanged;
}
- boolean updateSets(Node currentNode) {
- // Set input set according to output set of pred states of current state
- setInSet(currentNode);
+ void updateTheEdge(Node currentNode, Transition transition) {
+ if (parentNode.getOutgoingEdges().containsKey(currentNode)) {
+ Edge currentEdge = parentNode.getOutgoingEdges().get(currentNode);
+ if (currentEdge.getSetSetMap().containsKey(transition)) { // Update the transition
+ if (manual)
+ currentEdge.getSetSetMap().put(transition, tempSetSet);
+ else
+ currentEdge.getSetSetMap().get(transition).addAll(tempSetSet);
+ } else { // Add a new transition
+ currentEdge.getSetSetMap().put(transition, tempSetSet);
+ }
+ } else {
+ parentNode.getOutgoingEdges().put(currentNode, new Edge(parentNode, currentNode));
+ Edge currentEdge = parentNode.getOutgoingEdges().get(currentNode);
+ currentEdge.getSetSetMap().put(transition, tempSetSet);
+ }
- // Set outSet according to inSet, and setSet of current node, check if there is a change
- return setOutSet(currentNode);
+ // Update the last writer and last value for this edge for each varName
+ Edge currentEdge = parentNode.getOutgoingEdges().get(currentNode);
+ ArrayList<NameValuePair> setSet = currentEdge.getSetSetMap().get(transition);
+ for (int i = 0;i < setSet.size();i++) {
+ NameValuePair nameValuePair = setSet.get(i);
+ currentEdge.getLastWriter().put(nameValuePair.getVarName(), nameValuePair.getAppNum());
+ currentEdge.getLastValue().put(nameValuePair.getVarName(), nameValuePair.getValue());
+ }
}
+
+
static class Node {
- Integer id;
+ Integer id;
HashSet<Node> predecessors = new HashSet<Node>();
HashSet<Node> successors = new HashSet<Node>();
- HashSet<NameValuePair> inSet = new HashSet<NameValuePair>();
- HashSet<NameValuePair> setSet = new HashSet<NameValuePair>();
HashSet<NameValuePair> outSet = new HashSet<NameValuePair>();
+ HashMap<Node, Edge> outgoingEdges = new HashMap<Node, Edge>();
Node(Integer id) {
- this.id = id;
- }
-
- void addPredecessor(Node node) {
- predecessors.add(node);
- }
-
- void addSuccessor(Node node) {
- successors.add(node);
- }
-
- void setSetSet(HashSet<NameValuePair> setSet, boolean isManual) {
- if (isManual)
- this.setSet = new HashSet<NameValuePair>();
- for (NameValuePair i : setSet) {
- this.setSet.add(new NameValuePair(i.getAppNum(), i.getValue(), i.getVarName(), i.getIsManual()));
- }
+ this.id = id;
}
Integer getId() {
return successors;
}
- HashSet<NameValuePair> getInSet() {
- return inSet;
+ HashSet<NameValuePair> getOutSet() {
+ return outSet;
}
- HashSet<NameValuePair> getSetSet() {
- return setSet;
+ HashMap<Node, Edge> getOutgoingEdges() {
+ return outgoingEdges;
}
+ }
- HashSet<NameValuePair> getOutSet() {
- return outSet;
+ static class Edge {
+ Node source, destination;
+ HashMap<String, Integer> lastWriter = new HashMap<String, Integer>();
+ HashMap<String, String> lastValue = new HashMap<String, String>();
+ HashMap<Transition, ArrayList<NameValuePair>> setSetMap = new HashMap<Transition, ArrayList<NameValuePair>>();
+
+ Edge(Node source, Node destination) {
+ this.source = source;
+ this.destination = destination;
+ }
+
+ Node getSource() {
+ return source;
+ }
+
+ Node getDestination() {
+ return destination;
+ }
+
+ HashMap<Transition, ArrayList<NameValuePair>> getSetSetMap() {
+ return setSetMap;
+ }
+
+ HashMap<String, Integer> getLastWriter() {
+ return lastWriter;
+ }
+
+ HashMap<String, String> getLastValue() {
+ return lastValue;
}
}
boolean isManual;
NameValuePair(Integer appNum, String value, String varName, boolean isManual) {
- this.appNum = appNum;
- this.value = value;
- this.varName = varName;
- this.isManual = isManual;
+ this.appNum = appNum;
+ this.value = value;
+ this.varName = varName;
+ this.isManual = isManual;
}
void setAppNum(Integer appNum) {
@Override
public boolean equals(Object o) {
- if (o instanceof NameValuePair) {
- NameValuePair other = (NameValuePair) o;
- if (varName.equals(other.getVarName()))
- return appNum.equals(other.getAppNum());
- }
- return false;
+ if (o instanceof NameValuePair) {
+ NameValuePair other = (NameValuePair) o;
+ if (varName.equals(other.getVarName()))
+ return appNum.equals(other.getAppNum());
+ }
+ return false;
}
@Override
// Update the parent node
if (nodes.containsKey(id)) {
- parentNode = nodes.get(id);
+ parentNode = nodes.get(id);
} else {
- parentNode = new Node(id);
+ parentNode = new Node(id);
}
}
@Override
public void stateAdvanced(Search search) {
String theEnd = null;
+ Transition transition = search.getTransition();
id = search.getStateId();
depth = search.getDepth();
operation = "forward";
- // Add the node to the list of nodes
- nodes.put(id, new Node(id));
+ // Add the node to the list of nodes
+ if (nodes.get(id) == null)
+ nodes.put(id, new Node(id));
+
Node currentNode = nodes.get(id);
- // Update the setSet for this new node
- if (isSet) {
- currentNode.setSetSet(tempSetSet, manual);
- tempSetSet = new HashSet<NameValuePair>();
- isSet = false;
- manual = false;
- }
+ // Update the edge based on the current transition
+ updateTheEdge(currentNode, transition);
+
+ // Reset the temporary variables and flags
+ tempSetSet = new ArrayList<NameValuePair>();
+ manual = false;
+
+ // Check for the conflict in this transition
+ conflictFound = checkForConflict(parentNode, currentNode, transition);
if (search.isNewState()) {
detail = "new";
// Updating the predecessors for this node
// Check if parent node is already in successors of the current node or not
if (!(currentNode.getPredecessors().contains(parentNode)))
- currentNode.addPredecessor(parentNode);
+ currentNode.getPredecessors().add(parentNode);
// Update the successors for this node
// Check if current node is already in successors of the parent node or not
if (!(parentNode.getSuccessors().contains(currentNode)))
- parentNode.addSuccessor(currentNode);
-
- // Update the sets, check if the outSet is changed or not
- boolean isChanged = updateSets(currentNode);
-
- // Check for a conflict
- conflictFound = checkForConflict(currentNode);
+ parentNode.getSuccessors().add(currentNode);
+ // Update the outset of the current node and check if it is changed or not to propagate the change
+ boolean isChanged = updateTheOutSet(parentNode, currentNode);
+
// Check if the outSet of this state has changed, update all of its successors' sets if any
if (isChanged)
conflictFound = conflictFound || propagateTheChange(currentNode);
// Update the parent node
if (nodes.containsKey(id)) {
- parentNode = nodes.get(id);
+ parentNode = nodes.get(id);
} else {
- parentNode = new Node(id);
+ parentNode = new Node(id);
}
}
// Update the parent node
if (nodes.containsKey(id)) {
- parentNode = nodes.get(id);
+ parentNode = nodes.get(id);
} else {
- parentNode = new Node(id);
+ parentNode = new Node(id);
}
}
if ((inst instanceof JVMLocalVariableInstruction) ||
(inst instanceof JVMFieldInstruction))
{
- if (frame.getTopPos() < 0)
- return(null);
+ if (frame.getTopPos() < 0)
+ return(null);
- lo = frame.peek();
- hi = frame.getTopPos() >= 1 ? frame.peek(1) : 0;
+ lo = frame.peek();
+ hi = frame.getTopPos() >= 1 ? frame.peek(1) : 0;
- return(decodeValue(type, lo, hi));
+ return(decodeValue(type, lo, hi));
}
if (inst instanceof JVMArrayElementInstruction)
return null;
}
+ private void writeWriterAndValue(String writer, String value, String var) {
+ // Update the temporary Set set.
+ NameValuePair temp = new NameValuePair(1, value, var, manual);
+ if (writer.equals("App2"))
+ temp = new NameValuePair(2, value, var, manual);
+
+ tempSetSet.add(temp);
+ }
+
@Override
public void instructionExecuted(VM vm, ThreadInfo ti, Instruction nextInsn, Instruction executedInsn) {
- // Instantiate timeoutTimer
if (timeout > 0) {
if (System.currentTimeMillis() - startTime > timeout) {
StringBuilder sbTimeOut = new StringBuilder();
sb.append(errorMessage);
Instruction nextIns = ti.createAndThrowException("java.lang.RuntimeException", sb.toString());
ti.setNextPC(nextIns);
- } else if (executedInsn instanceof WriteInstruction) {
- String varId = ((WriteInstruction) executedInsn).getFieldInfo().getFullName();
- for(String var : conflictSet) {
-
- if (varId.contains(var)) {
- // Get variable info
+ } else {
+ if (conflictSet.contains(LOCATION_VAR)) {
+ MethodInfo mi = executedInsn.getMethodInfo();
+ // Find the last load before return and get the value here
+ if (mi.getName().equals(SET_LOCATION_METHOD) &&
+ executedInsn instanceof ALOAD && nextInsn instanceof ARETURN) {
byte type = getType(ti, executedInsn);
String value = getValue(ti, executedInsn, type);
- String writer = getWriter(ti.getStack(), appSet);
- // Just return if the writer is not one of the listed apps in the .jpf file
- if (writer == null)
- return;
-
- if (getWriter(ti.getStack(), manualSet) != null)
- manual = true;
-
- // Update the temporary Set set.
- if (writer.equals("App1"))
- tempSetSet.add(new NameValuePair(1, value, var, manual));
- else if (writer.equals("App2"))
- tempSetSet.add(new NameValuePair(2, value, var, manual));
- // Set isSet to true
- isSet = true;
-
- }
- }
-
- }
-
- }
+ // Extract the writer app name
+ ClassInfo ci = mi.getClassInfo();
+ String writer = ci.getName();
+ // Update the temporary Set set.
+ writeWriterAndValue(writer, value, LOCATION_VAR);
+ }
+ } else {
+ if (executedInsn instanceof WriteInstruction) {
+ String varId = ((WriteInstruction) executedInsn).getFieldInfo().getFullName();
+
+ for (String var : conflictSet) {
+ if (varId.contains(var)) {
+ // Get variable info
+ byte type = getType(ti, executedInsn);
+ String value = getValue(ti, executedInsn, type);
+ String writer = getWriter(ti.getStack(), appSet);
+ // Just return if the writer is not one of the listed apps in the .jpf file
+ if (writer == null)
+ return;
+
+ if (getWriter(ti.getStack(), manualSet) != null)
+ manual = true;
+
+ // Update the temporary Set set.
+ writeWriterAndValue(writer, value, var);
+ }
+ }
+ }
+ }
+ }
+ }
}