// DPOR-related fields
// Basic information
private Integer[] choices;
- private Integer[] refChoices;
+ private Integer[] refChoices; // Second reference to a copy of choices (choices may be modified for fair scheduling)
private int choiceCounter;
+ private int lastCGStateId; // Record the state of the currently active CG
private int maxEventChoice;
// Data structure to track the events seen by each state to track cycles (containing all events) for termination
private HashSet<Integer> currVisitedStates; // States being visited in the current execution
// Data structure to analyze field Read/Write accesses and conflicts
private HashMap<Integer, LinkedList<Integer[]>> backtrackMap; // Track created backtracking points
private PriorityQueue<Integer> backtrackStateQ; // Heap that returns the latest state
- private ArrayList<IntChoiceFromSet> cgList; // Record CGs for backtracking points
+ private ArrayList<BacktrackPoint> backtrackPointList; // Record backtrack points (CG and choice)
private HashMap<Integer, IntChoiceFromSet> cgMap; // Maps state IDs to CGs
private HashMap<Integer, HashSet<Integer>> conflictPairMap; // Record conflicting events
-// private HashSet<IntChoiceFromSet> activeBacktrackCGs; // Record active backtrack CGs
+ private HashSet<String> doneBacktrackSet; // Record state ID and trace that are done
private HashMap<Integer, ReadWriteSet> readWriteFieldsMap; // Record fields that are accessed
// Visible operation dependency graph implementation (SPIN paper) related fields
} else {
out = null;
}
- // DPOR-related
- choices = null;
- refChoices = null;
- choiceCounter = 0;
- maxEventChoice = 0;
- // Cycle tracking
- currVisitedStates = new HashSet<>();
- justVisitedStates = new HashSet<>();
- prevVisitedStates = new HashSet<>();
- stateToEventMap = new HashMap<>();
- // Backtracking
- backtrackMap = new HashMap<>();
- backtrackStateQ = new PriorityQueue<>();
- cgList = new ArrayList<>();
- cgMap = new HashMap<>();
- conflictPairMap = new HashMap<>();
-// activeBacktrackCGs = new HashSet<>();
- readWriteFieldsMap = new HashMap<>();
- // VOD graph
- prevChoiceValue = -1;
- vodGraphMap = new HashMap<>();
- // Booleans
isBooleanCGFlipped = false;
- isEndOfExecution = false;
- isFirstResetDone = false;
+ initializeStatesVariables();
}
@Override
int choiceIndex = choiceCounter % choices.length;
icsCG.advance(choices[choiceIndex]);
// Index the ChoiceGenerator to set backtracking points
- cgList.add(icsCG);
+ BacktrackPoint backtrackPoint = new BacktrackPoint(icsCG, choices[choiceIndex]);
+ backtrackPointList.add(backtrackPoint);
} else {
// Set done all CGs while transitioning to a new execution
icsCG.setDone();
if (stateReductionMode) {
// Check the boolean CG and if it is flipped, we are resetting the analysis
-// if (currentCG instanceof BooleanChoiceGenerator) {
-// if (!isBooleanCGFlipped) {
-// isBooleanCGFlipped = true;
-// } else {
-// initializeStateReduction();
-// }
-// }
+ if (currentCG instanceof BooleanChoiceGenerator) {
+ if (!isBooleanCGFlipped) {
+ isBooleanCGFlipped = true;
+ } else {
+ // Allocate new objects for data structure when the boolean is flipped from "false" to "true"
+ initializeStatesVariables();
+ }
+ }
// Check every choice generated and ensure fair scheduling!
if (currentCG instanceof IntChoiceFromSet) {
IntChoiceFromSet icsCG = (IntChoiceFromSet) currentCG;
// This class compactly stores backtracking points: 1) backtracking ChoiceGenerator, and 2) backtracking choices
private class BacktrackPoint {
private IntChoiceFromSet backtrackCG; // CG to backtrack from
- private Integer[] backtrackChoices; // Choices to set for this backtrack CG
+ private int choice; // Choice chosen at this backtrack point
- public BacktrackPoint(IntChoiceFromSet cg, Integer[] choices) {
+ public BacktrackPoint(IntChoiceFromSet cg, int cho) {
backtrackCG = cg;
- backtrackChoices = choices;
+ choice = cho;
}
public IntChoiceFromSet getBacktrackCG() {
return backtrackCG;
}
- public Integer[] getBacktrackChoices() {
- return backtrackChoices;
+ public int getChoice() {
+ return choice;
}
}
return true;
}
+ private void initializeStatesVariables() {
+ // DPOR-related
+ choices = null;
+ refChoices = null;
+ choiceCounter = 0;
+ lastCGStateId = 0;
+ maxEventChoice = 0;
+ // Cycle tracking
+ currVisitedStates = new HashSet<>();
+ justVisitedStates = new HashSet<>();
+ prevVisitedStates = new HashSet<>();
+ stateToEventMap = new HashMap<>();
+ // Backtracking
+ backtrackMap = new HashMap<>();
+ backtrackStateQ = new PriorityQueue<>(Collections.reverseOrder());
+ backtrackPointList = new ArrayList<>();
+ cgMap = new HashMap<>();
+ conflictPairMap = new HashMap<>();
+ doneBacktrackSet = new HashSet<>();
+ readWriteFieldsMap = new HashMap<>();
+ // VOD graph
+ prevChoiceValue = -1;
+ vodGraphMap = new HashMap<>();
+ // Booleans
+ isEndOfExecution = false;
+ isFirstResetDone = false;
+ }
+
private void mapStateToEvent(int nextChoiceValue) {
// Update all states with this event/choice
// This means that all past states now see this transition
backtrackList = backtrackMap.get(stateId);
} else {
backtrackList = new LinkedList<>();
+ backtrackMap.put(stateId, backtrackList);
}
backtrackList.addFirst(newChoiceList);
// Add CG for this state ID if there isn't one yet
Integer[] newChoiceList = new Integer[refChoices.length];
// Put the conflicting event numbers first and reverse the order
int actualCurrCho = currentChoice % refChoices.length;
- int actualConfEvtNum = confEvtNum % refChoices.length;
- newChoiceList[0] = refChoices[actualCurrCho];
- newChoiceList[1] = refChoices[actualConfEvtNum];
+ // We use the actual choices here in case they have been modified/adjusted by the fair scheduling method
+ newChoiceList[0] = choices[actualCurrCho];
+ newChoiceList[1] = backtrackPointList.get(confEvtNum).getChoice();
// Put the rest of the event numbers into the array starting from the minimum to the upper bound
for (int i = 0, j = 2; i < refChoices.length; i++) {
if (refChoices[i] != newChoiceList[0] && refChoices[i] != newChoiceList[1]) {
j++;
}
}
- // Record the backtracking point in the stack as well
- IntChoiceFromSet backtrackCG = cgList.get(confEvtNum);
+ // Get the backtrack CG for this backtrack point
+ IntChoiceFromSet backtrackCG = backtrackPointList.get(confEvtNum).getBacktrackCG();
+ // Check if this trace has been done starting from this state
+ if (isTraceConstructed(newChoiceList, backtrackCG)) {
+ return;
+ }
//BacktrackPoint backtrackPoint = new BacktrackPoint(backtrackCG, newChoiceList);
addNewBacktrackPoint(backtrackCG, newChoiceList);
}
private void exploreNextBacktrackPoints(IntChoiceFromSet icsCG, VM vm) {
// We can start exploring the next backtrack point after the current CG is advanced at least once
if (icsCG.getNextChoiceIndex() > 0) {
- if (backtrackMap.isEmpty()) {
- // This means we are reaching the end of our execution: no more backtracking points to explore
- return;
+ // Check if we are reaching the end of our execution: no more backtracking points to explore
+ if (!backtrackMap.isEmpty()) {
+ setNextBacktrackPoint(icsCG);
}
- setNextBacktrackPoint(icsCG);
// Save all the visited states when starting a new execution of trace
prevVisitedStates.addAll(currVisitedStates);
currVisitedStates.clear();
int actualEvtCntr = eventCounter % refChoices.length;
int actualCurrCho = currentChoice % refChoices.length;
// Skip if this event does not have any Read/Write set or the two events are basically the same event (number)
- if (!readWriteFieldsMap.containsKey(eventCounter) || (actualEvtCntr == actualCurrCho)) {
+ if (!readWriteFieldsMap.containsKey(eventCounter) || choices[actualCurrCho] == choices[actualEvtCntr]) {
return false;
}
ReadWriteSet rwSet = readWriteFieldsMap.get(eventCounter);
return true;
}
+ private boolean isTraceConstructed(Integer[] choiceList, IntChoiceFromSet backtrackCG) {
+ // Concatenate state ID and trace in a string, e.g., "1:10234"
+ int stateId = backtrackCG.getStateId();
+ StringBuilder sb = new StringBuilder();
+ sb.append(stateId);
+ sb.append(':');
+ for(Integer choice : choiceList) {
+ sb.append(choice);
+ }
+ // Check if the trace has been constructed as a backtrack point for this state
+ if (doneBacktrackSet.contains(sb.toString())) {
+ return true;
+ }
+ doneBacktrackSet.add(sb.toString());
+ return false;
+ }
+
private void resetStatesForNewExecution(IntChoiceFromSet icsCG) {
if (choices == null || choices != icsCG.getAllChoices()) {
// Reset state variables
- choiceCounter = 1;
+ choiceCounter = 0;
choices = icsCG.getAllChoices();
refChoices = copyChoices(choices);
+ lastCGStateId = icsCG.getStateId();
// Clearing data structures
- backtrackMap.clear();
conflictPairMap.clear();
readWriteFieldsMap.clear();
stateToEventMap.clear();
isEndOfExecution = false;
- // Adding this CG as the first CG for this execution
- cgList.add(icsCG);
+ // Adding this CG as the first backtrack point for this execution
+ backtrackPointList.add(new BacktrackPoint(icsCG, choices[0]));
}
}
- private IntChoiceFromSet setBacktrackCG(int stateId) {
+ private void setBacktrackCG(int stateId) {
// Set a backtrack CG based on a state ID
IntChoiceFromSet backtrackCG = cgMap.get(stateId);
LinkedList<Integer[]> backtrackChoices = backtrackMap.get(stateId);
backtrackMap.remove(stateId);
backtrackStateQ.remove(stateId);
}
- return backtrackCG;
}
private void setNextBacktrackPoint(IntChoiceFromSet icsCG) {
for (Integer stateId : cgMap.keySet()) {
setBacktrackCG(stateId);
}
-// activeBacktrackCGs.addAll(cgMap.values());
isFirstResetDone = true;
} else {
- // Check if we still have backtrack points for the current CG
- int currStateId = icsCG.getStateId();
- if (backtrackMap.containsKey(currStateId)) {
- setBacktrackCG(currStateId);
+ // Check if we still have backtrack points for the last state after the last backtrack
+ if (backtrackMap.containsKey(lastCGStateId)) {
+ setBacktrackCG(lastCGStateId);
} else {
-// activeBacktrackCGs.remove(icsCG);
// We try to reset new CGs (if we do have) when we are running out of active CGs
if (!backtrackStateQ.isEmpty()) {
// Reset the next CG with the latest state
int hiStateId = backtrackStateQ.peek();
- IntChoiceFromSet backtrackCG = setBacktrackCG(hiStateId);
-// activeBacktrackCGs.add(backtrackCG);
+ setBacktrackCG(hiStateId);
}
}
}
// Clear unused CGs
- for(IntChoiceFromSet cg : cgList) {
+ for(BacktrackPoint backtrackPoint : backtrackPointList) {
+ IntChoiceFromSet cg = backtrackPoint.getBacktrackCG();
if (!backtrackCGs.contains(cg)) {
cg.setDone();
}
}
- cgList.clear();
+ backtrackPointList.clear();
}
// --- Functions related to the visible operation dependency graph implementation discussed in the SPIN paper
projects / jpf-core.git / blobdiff