// Reference to the state graph in the ConflictTracker class
private HashMap<Integer, ConflictTracker.Node> stateGraph;
+ private HashMap<Integer, HashSet<Integer>> stateToEventMap;
+ // Map state to event
// Visited states in the previous and current executions/traces for terminating condition
private HashSet<Integer> prevVisitedStates;
private HashSet<Integer> currVisitedStates;
unusedCG = new HashSet<>();
// TODO: We are assuming that the StateReducer is always used together with the ConflictTracker
stateGraph = ConflictTracker.nodes;
+ stateToEventMap = new HashMap<>();
prevVisitedStates = new HashSet<>();
currVisitedStates = new HashSet<>();
initializeStateReduction();
}
}
+ private IntChoiceFromSet setNewCG(IntChoiceFromSet icsCG) {
+ icsCG.setNewValues(choices);
+ icsCG.reset();
+ // Use a modulo since choiceCounter is going to keep increasing
+ int choiceIndex = choiceCounter % (choices.length - 1);
+ icsCG.advance(choices[choiceIndex]);
+ return icsCG;
+ }
+
+ private void initializeChoiceGenerators(IntChoiceFromSet icsCG, Integer[] cgChoices) {
+ if (choiceCounter <= choiceUpperBound && !cgMap.containsValue(choiceCounter)) {
+ // Update the choices of the first CG and add '-1'
+ if (choices == null) {
+ // Initialize backtrack set that stores all the explored backtrack lists
+ maxUpperBound = cgChoices.length;
+ // All the choices are always the same so we only need to update it once
+ choices = new Integer[cgChoices.length + 1];
+ System.arraycopy(cgChoices, 0, choices, 0, cgChoices.length);
+ choices[choices.length - 1] = -1;
+ String firstChoiceListString = buildStringFromChoiceList(choices);
+ backtrackSet.add(firstChoiceListString);
+ }
+ IntChoiceFromSet setCG = setNewCG(icsCG);
+ cgMap.put(setCG, choices[choiceCounter]);
+ } else {
+ // We repeat the same trace if a state match is not found yet
+ IntChoiceFromSet setCG = setNewCG(icsCG);
+ unusedCG.add(setCG);
+ }
+ //choiceCounter = choiceCounter < choiceUpperBound ? choiceCounter + 1 : 0;
+ choiceCounter++;
+ }
+
@Override
public void choiceGeneratorRegistered(VM vm, ChoiceGenerator<?> nextCG, ThreadInfo currentThread, Instruction executedInstruction) {
if (stateReductionMode) {
}
// Record the subsequent Integer CGs only until we hit the upper bound
if (!isResetAfterAnalysis) {
- if (choiceCounter <= choiceUpperBound && !cgMap.containsValue(choiceCounter)) {
- // Update the choices of the first CG and add '-1'
- if (choices == null) {
- // Initialize backtrack set that stores all the explored backtrack lists
- maxUpperBound = cgChoices.length;
- // All the choices are always the same so we only need to update it once
- choices = new Integer[cgChoices.length + 1];
- System.arraycopy(cgChoices, 0, choices, 0, cgChoices.length);
- choices[choices.length - 1] = -1;
- String firstChoiceListString = buildStringFromChoiceList(choices);
- backtrackSet.add(firstChoiceListString);
- }
- icsCG.setNewValues(choices);
- icsCG.reset();
- // Advance the current Integer CG
- // This way we explore all the event numbers in the first pass
- icsCG.advance(choices[choiceCounter]);
- cgMap.put(icsCG, choices[choiceCounter]);
- } else {
- // We repeat the same trace if a state match is not found yet
- icsCG.setNewValues(choices);
- icsCG.reset();
- // Use a modulo since choiceCounter is going to keep increasing
- int choiceIndex = choiceCounter % (choices.length - 1);
- icsCG.advance(choices[choiceIndex]);
- unusedCG.add(icsCG);
- }
- //choiceCounter = choiceCounter < choiceUpperBound ? choiceCounter + 1 : 0;
- choiceCounter++;
+ initializeChoiceGenerators(icsCG, cgChoices);
} else {
// Set new CGs to done so that the search algorithm explores the existing CGs
icsCG.setDone();
// We terminate the execution iff:
// (1) the state has been visited in the current execution
// (2) the state has one or more cycles that involve all the events
+ // With simple approach we only need to check for a re-visited state.
+ // Basically, we have to check that we have executed all events between two occurrences of such state.
private boolean containsCyclesWithAllEvents(int stId) {
HashSet<ConflictTracker.Node> visitingStates = new HashSet<>();
- HashSet<Integer> visitedEvents = new HashSet<>();
+ HashSet<Integer> visitedEvents = stateToEventMap.get(stId);
boolean containsCyclesWithAllEvts = false;
- ConflictTracker.Node currNode = stateGraph.get(stId);
- dfsFindCycles(currNode, visitingStates, visitedEvents, new HashSet<>());
if (checkIfAllEventsInvolved(visitedEvents)) {
containsCyclesWithAllEvts = true;
}
return containsCyclesWithAllEvts;
}
- private void dfsFindCycles(ConflictTracker.Node currNode, HashSet<ConflictTracker.Node> visitingStates,
- HashSet<Integer> visitedEvents, HashSet<Integer> visitingEvents) {
-
- // Stop when there is a cycle and record all the events
- if (visitingStates.contains(currNode)) {
- visitedEvents.addAll(visitingEvents);
- } else {
- visitingStates.add(currNode);
- for(ConflictTracker.Edge edge : currNode.getOutEdges()) {
- visitingEvents.add(edge.getEventNumber());
- dfsFindCycles(edge.getDst(), visitingStates, visitedEvents, visitingEvents);
- visitingEvents.remove(edge.getEventNumber());
- }
- visitingStates.remove(currNode);
- }
- }
+ // TODO: The following is a full-blown graph traversal that we can do if we need to in the future
+ // Detect cycles in the current execution/trace
+ // We terminate the execution iff:
+ // (1) the state has been visited in the current execution
+ // (2) the state has one or more cycles that involve all the events
+// private boolean containsCyclesWithAllEvents(int stId) {
+//
+// HashSet<ConflictTracker.Node> visitingStates = new HashSet<>();
+// HashSet<Integer> visitedEvents = new HashSet<>();
+// boolean containsCyclesWithAllEvts = false;
+// ConflictTracker.Node currNode = stateGraph.get(stId);
+// dfsFindCycles(currNode, visitingStates, visitedEvents, new HashSet<>());
+// if (checkIfAllEventsInvolved(visitedEvents)) {
+// containsCyclesWithAllEvts = true;
+// }
+//
+// return containsCyclesWithAllEvts;
+// }
+//
+// private void dfsFindCycles(ConflictTracker.Node currNode, HashSet<ConflictTracker.Node> visitingStates,
+// HashSet<Integer> visitedEvents, HashSet<Integer> visitingEvents) {
+//
+// // Stop when there is a cycle and record all the events
+// if (visitingStates.contains(currNode)) {
+// visitedEvents.addAll(visitingEvents);
+// } else {
+// visitingStates.add(currNode);
+// for(ConflictTracker.Edge edge : currNode.getOutEdges()) {
+// visitingEvents.add(edge.getEventNumber());
+// dfsFindCycles(edge.getDst(), visitingStates, visitedEvents, visitingEvents);
+// visitingEvents.remove(edge.getEventNumber());
+// }
+// visitingStates.remove(currNode);
+// }
+// }
private boolean checkIfAllEventsInvolved(HashSet<Integer> visitedEvents) {
currVisitedStates.clear();
}
+ private void updateChoices(IntChoiceFromSet icsCG) {
+ if (choices == null || choices != icsCG.getAllChoices()) {
+ currCG = icsCG;
+ choices = icsCG.getAllChoices();
+ // Reset a few things for the sub-graph
+ conflictPairMap.clear();
+ readWriteFieldsMap.clear();
+ choiceCounter = 0;
+ }
+ }
+
+ private void exploreNextBacktrackSets(IntChoiceFromSet icsCG) {
+ // Traverse the sub-graphs
+ if (isResetAfterAnalysis) {
+ // Advance choice counter for sub-graphs
+ choiceCounter++;
+ // Do this for every CG after finishing each backtrack list
+ // We try to update the CG with a backtrack list if the state has been visited multiple times
+ if ((icsCG.getNextChoice() == -1 || choiceCounter > 1) && cgMap.containsKey(icsCG)) {
+ int event = cgMap.get(icsCG);
+ LinkedList<Integer[]> choiceLists = backtrackMap.get(event);
+ if (choiceLists != null && choiceLists.peekFirst() != null) {
+ Integer[] choiceList = choiceLists.removeFirst();
+ // Deploy the new choice list for this CG
+ icsCG.setNewValues(choiceList);
+ icsCG.reset();
+ } else {
+ // Set done if this was the last backtrack list
+ icsCG.setDone();
+ }
+ saveVisitedStates();
+ }
+ } else {
+ // Update and reset the CG if needed (do this for the first time after the analysis)
+ // Start backtracking if this is a visited state and it is not a repeating state
+ resetAllCGs();
+ isResetAfterAnalysis = true;
+ }
+ }
+
@Override
public void choiceGeneratorAdvanced(VM vm, ChoiceGenerator<?> currentCG) {
if (currentCG instanceof IntChoiceFromSet) {
IntChoiceFromSet icsCG = (IntChoiceFromSet) currentCG;
// Update the current pointer to the current set of choices
- if (choices == null || choices != icsCG.getAllChoices()) {
- currCG = icsCG;
- choices = icsCG.getAllChoices();
- // Reset a few things for the sub-graph
- conflictPairMap.clear();
- readWriteFieldsMap.clear();
- choiceCounter = 0;
- }
+ updateChoices(icsCG);
// Check if we have seen this state or this state contains cycles that involve all events
if (prevVisitedStates.contains(stateId) || containsCyclesWithAllEvents(stateId)) {
- // Traverse the sub-graphs
- if (isResetAfterAnalysis) {
- // Advance choice counter for sub-graphs
- choiceCounter++;
- // Do this for every CG after finishing each backtrack list
- // We try to update the CG with a backtrack list if the state has been visited multiple times
- if ((icsCG.getNextChoice() == -1 || choiceCounter > 1) && cgMap.containsKey(icsCG)) {
- int event = cgMap.get(icsCG);
- LinkedList<Integer[]> choiceLists = backtrackMap.get(event);
- if (choiceLists != null && choiceLists.peekFirst() != null) {
- Integer[] choiceList = choiceLists.removeFirst();
- // Deploy the new choice list for this CG
- icsCG.setNewValues(choiceList);
- icsCG.reset();
- } else {
- // Set done if this was the last backtrack list
- icsCG.setDone();
- }
- saveVisitedStates();
- }
- } else {
- // Update and reset the CG if needed (do this for the first time after the analysis)
- // Start backtracking if this is a visited state and it is not a repeating state
- resetAllCGs();
- isResetAfterAnalysis = true;
- }
+ exploreNextBacktrackSets(icsCG);
}
// Update the VOD graph always with the latest
updateVODGraph(icsCG.getNextChoice());
choiceSet.add(currChoice);
}
+ private void mapStateToEvent(Search search) {
+ // Insert state ID and event choice into the map
+ HashSet<Integer> eventSet;
+ if (stateToEventMap.containsKey(stateId)) {
+ eventSet = stateToEventMap.get(stateId);
+ } else {
+ eventSet = new HashSet<>();
+ stateToEventMap.put(stateId, eventSet);
+ }
+ eventSet.add(prevChoiceValue);
+ }
+
+ private void updateStateInfo(Search search) {
+ if (stateReductionMode) {
+ // Update the state variables
+ // Line 19 in the paper page 11 (see the heading note above)
+ stateId = search.getStateId();
+ currVisitedStates.add(stateId);
+ mapStateToEvent(search);
+ }
+ }
+
@Override
public void stateAdvanced(Search search) {
if (debugMode) {
out.println("\n==> DEBUG: The state is forwarded to state with id: " + id + " with depth: " + depth +
" which is " + detail + " Transition: " + transition + "\n");
}
- if (stateReductionMode) {
- // Update the state ID variables
- stateId = search.getStateId();
- currVisitedStates.add(stateId);
- }
+ updateStateInfo(search);
}
@Override
transition = search.getTransition();
detail = null;
- // Update the state variables
- // Line 19 in the paper page 11 (see the heading note above)
- stateId = search.getStateId();
- currVisitedStates.add(stateId);
-
out.println("\n==> DEBUG: The state is backtracked to state with id: " + id + " -- Transition: " + transition +
" and depth: " + depth + "\n");
}
+ updateStateInfo(search);
}
@Override
public void instructionExecuted(VM vm, ThreadInfo ti, Instruction nextInsn, Instruction executedInsn) {
if (stateReductionMode) {
if (isInitialized) {
- if (choiceCounter <= 0 || choiceCounter > choices.length - 1) {
+ int currentChoice = (choiceCounter % (choices.length - 1)) - 1;
+ if (currentChoice < 0) {
// We do not compute the conflicts for the choice '-1'
return;
}
- int currentChoice = choiceCounter - 1;
// Record accesses from executed instructions
if (executedInsn instanceof JVMFieldInstruction) {
// Analyze only after being initialized
projects / jpf-core.git / blobdiff