import java.io.FileWriter;
import java.io.PrintWriter;
+import java.lang.reflect.Field;
import java.util.*;
import java.util.logging.Logger;
import java.io.IOException;
private int choiceCounter;
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
- private HashSet<Integer> justVisitedStates; // States just visited in the previous choice/event
- private HashSet<Integer> prevVisitedStates; // States visited in the previous execution
+ private HashSet<Integer> currVisitedStates; // States being visited in the current execution
+ private HashSet<Integer> justVisitedStates; // States just visited in the previous choice/event
+ private HashSet<Integer> prevVisitedStates; // States visited in the previous execution
+ private HashSet<ClassInfo> nonRelevantClasses;// Class info objects of non-relevant classes
+ private HashSet<FieldInfo> nonRelevantFields; // Field info objects of non-relevant fields
+ private HashSet<FieldInfo> relevantFields; // Field info objects of relevant fields
private HashMap<Integer, HashSet<Integer>> stateToEventMap;
// Data structure to analyze field Read/Write accesses and conflicts
private HashMap<Integer, LinkedList<BacktrackExecution>> backtrackMap; // Track created backtracking points
private Execution currentExecution; // Holds the information about the current execution
private HashSet<String> doneBacktrackSet; // Record state ID and trace already constructed
private HashMap<Integer, RestorableVMState> restorableStateMap; // Maps state IDs to the restorable state object
- private HashMap<Integer, Integer> stateToChoiceCounterMap; // Maps state IDs to the choice counter
- private HashMap<Integer, HashSet<TransitionEvent>> rGraph; // Reachability graph for past executions
+ private RGraph rGraph; // R-Graph for past executions
// Boolean states
private boolean isBooleanCGFlipped;
isBooleanCGFlipped = false;
numOfConflicts = 0;
numOfTransitions = 0;
+ nonRelevantClasses = new HashSet<>();
+ nonRelevantFields = new HashSet<>();
+ relevantFields = new HashSet<>();
restorableStateMap = new HashMap<>();
initializeStatesVariables();
}
" which is " + detail + " Transition: " + transition + "\n");
}
if (stateReductionMode) {
- // Only add a transition into R-Graph when it advances the state
- addTransitionToRGRaph();
updateStateInfo(search);
}
}
@Override
public void choiceGeneratorAdvanced(VM vm, ChoiceGenerator<?> currentCG) {
-
if (stateReductionMode) {
// Check the boolean CG and if it is flipped, we are resetting the analysis
if (currentCG instanceof BooleanChoiceGenerator) {
// If this is a new CG then we need to update data structures
resetStatesForNewExecution(icsCG, vm);
// If we don't see a fair scheduling of events/choices then we have to enforce it
- fairSchedulingAndTransition(icsCG, vm);
+ ensureFairSchedulingAndSetupTransition(icsCG, vm);
// Update backtrack set of an executed event (transition): one transition before this one
updateBacktrackSet(currentExecution, choiceCounter - 1);
- // Explore the next backtrack point:
+ // Explore the next backtrack point:
// 1) if we have seen this state or this state contains cycles that involve all events, and
// 2) after the current CG is advanced at least once
if (terminateCurrentExecution() && choiceCounter > 0) {
currentChoice = checkAndAdjustChoice(currentChoice, vm);
// Record accesses from executed instructions
if (executedInsn instanceof JVMFieldInstruction) {
- // Analyze only after being initialized
- String fieldClass = ((JVMFieldInstruction) executedInsn).getFieldInfo().getFullName();
// We don't care about libraries
- if (!isFieldExcluded(fieldClass)) {
- analyzeReadWriteAccesses(executedInsn, fieldClass, currentChoice);
+ if (!isFieldExcluded(executedInsn)) {
+ analyzeReadWriteAccesses(executedInsn, currentChoice);
}
} else if (executedInsn instanceof INVOKEINTERFACE) {
// Handle the read/write accesses that occur through iterators
}
}
- // This class stores a representation of the execution graph node
+ // This class stores a representation of an execution
// TODO: We can modify this class to implement some optimization (e.g., clock-vector)
// TODO: We basically need to keep track of:
// TODO: (1) last read/write access to each memory location
- // TODO: (2) last state with two or more incoming events (transitions)
+ // TODO: (2) last state with two or more incoming events/transitions
private class Execution {
private HashMap<IntChoiceFromSet, Integer> cgToChoiceMap; // Map between CG to choice numbers for O(1) access
- private ArrayList<TransitionEvent> executionTrace; // The BacktrackPoint objects of this execution
+ private ArrayList<TransitionEvent> executionTrace; // The BacktrackPoint objects of this execution
+ private boolean isNew; // Track if this is the first time it is accessed
private HashMap<Integer, ReadWriteSet> readWriteFieldsMap; // Record fields that are accessed
private HashMap<Integer, TransitionEvent> stateToTransitionMap; // For O(1) access to backtrack point
public Execution() {
cgToChoiceMap = new HashMap<>();
executionTrace = new ArrayList<>();
+ isNew = true;
readWriteFieldsMap = new HashMap<>();
stateToTransitionMap = new HashMap<>();
}
cgToChoiceMap = null;
}
- public TransitionEvent getTransitionFromState(int stateId) {
- if (stateToTransitionMap.containsKey(stateId)) {
- return stateToTransitionMap.get(stateId);
- }
- return null;
- }
-
public int getChoiceFromCG(IntChoiceFromSet icsCG) {
return cgToChoiceMap.get(icsCG);
}
return executionTrace;
}
- public HashMap<Integer, ReadWriteSet> getReadWriteFieldsMap() {
- return readWriteFieldsMap;
- }
-
public TransitionEvent getFirstTransition() {
return executionTrace.get(0);
}
- public TransitionEvent getLastTransition() {
+ public HashMap<Integer, ReadWriteSet> getReadWriteFieldsMap() {
+ return readWriteFieldsMap;
+ }
+
+ public TransitionEvent getTransitionFromState(int stateId) {
+ if (stateToTransitionMap.containsKey(stateId)) {
+ return stateToTransitionMap.get(stateId);
+ }
+ // Return the latest transition for unseen states (that have just been encountered in this transition)
return executionTrace.get(executionTrace.size() - 1);
}
public boolean isNew() {
- return executionTrace.size() == 1;
+ if (isNew) {
+ // Right after this is accessed, it is no longer new
+ isNew = false;
+ return true;
+ }
+ return false;
}
public void mapCGToChoice(IntChoiceFromSet icsCG, int choice) {
// 1) a predecessor execution
// 2) the predecessor choice in that predecessor execution
private class Predecessor {
- private int predecessorChoice; // Predecessor choice
- private Execution predecessorExecution; // Predecessor execution
+ private int choice; // Predecessor choice
+ private Execution execution; // Predecessor execution
public Predecessor(int predChoice, Execution predExec) {
- predecessorChoice = predChoice;
- predecessorExecution = predExec;
- }
-
- public int getPredecessorChoice() {
- return predecessorChoice;
- }
-
- public Execution getPredecessorExecution() {
- return predecessorExecution;
- }
- }
-
- // This class compactly stores backtrack points:
- // 1) CG,
- // 2) state ID,
- // 3) choice,
- // 4) predecessors (for backward DFS).
- private class TransitionEvent {
- private IntChoiceFromSet transitionCG; // CG at this transition
- private int stateId; // State at this transition
- private int choice; // Choice chosen at this transition
- private Execution execution; // The execution where this transition belongs
- private int choiceCounter; // Choice counter at this transition
- private HashSet<Predecessor> predecessors; // Maps incoming events/transitions (execution and choice)
-
- public TransitionEvent() {
- transitionCG = null;
- stateId = -1;
- choice = -1;
- execution = null;
- choiceCounter = -1;
- predecessors = new HashSet<>();
- }
-
- public void setTransitionCG(IntChoiceFromSet cg) {
- transitionCG = cg;
- }
-
- public void setStateId(int stId) {
- stateId = stId;
- }
-
- public void setChoice(int cho) {
- choice = cho;
- }
-
- public void setChoiceCounter(int choCounter) {
- choiceCounter = choCounter;
- }
-
- public IntChoiceFromSet getTransitionCG() { return transitionCG; }
-
- public int getStateId() {
- return stateId;
+ choice = predChoice;
+ execution = predExec;
}
public int getChoice() {
return choice;
}
- public int getChoiceCounter() {
- return choiceCounter;
+ public Execution getExecution() {
+ return execution;
}
+ }
- public void setExecution(Execution exec) {
- execution = exec;
+ // This class represents a R-Graph (in the paper it is a state transition graph R)
+ // This implementation stores reachable transitions from and connects with past executions
+ private class RGraph {
+ private int hiStateId; // Maximum state Id
+ private HashMap<Integer, HashSet<TransitionEvent>> graph; // Reachable transitions from past executions
+
+ public RGraph() {
+ hiStateId = 0;
+ graph = new HashMap<>();
}
- public Execution getExecution() {
- return execution;
+ public void addReachableTransition(int stateId, TransitionEvent transition) {
+ HashSet<TransitionEvent> transitionSet;
+ if (graph.containsKey(stateId)) {
+ transitionSet = graph.get(stateId);
+ } else {
+ transitionSet = new HashSet<>();
+ graph.put(stateId, transitionSet);
+ }
+ // Insert into the set if it does not contain it yet
+ if (!transitionSet.contains(transition)) {
+ transitionSet.add(transition);
+ }
+ // Update highest state ID
+ if (hiStateId < stateId) {
+ hiStateId = stateId;
+ }
}
- public HashSet<Predecessor> getPredecessors() {
- return predecessors;
+ public HashSet<TransitionEvent> getReachableTransitionsAtState(int stateId) {
+ return graph.get(stateId);
}
- public void recordPredecessor(Execution execution, int choice) {
- predecessors.add(new Predecessor(choice, execution));
+ public HashSet<TransitionEvent> getReachableTransitions(int stateId) {
+ HashSet<TransitionEvent> reachableTransitions = new HashSet<>();
+ // All transitions from states higher than the given state ID (until the highest state ID) are reachable
+ for(int stId = stateId; stId <= hiStateId; stId++) {
+ reachableTransitions.addAll(graph.get(stId));
+ }
+ return reachableTransitions;
}
}
}
}
+ // This class compactly stores transitions:
+ // 1) CG,
+ // 2) state ID,
+ // 3) choice,
+ // 4) predecessors (for backward DFS).
+ private class TransitionEvent {
+ private int choice; // Choice chosen at this transition
+ private int choiceCounter; // Choice counter at this transition
+ private Execution execution; // The execution where this transition belongs
+ private HashSet<Predecessor> predecessors; // Maps incoming events/transitions (execution and choice)
+ private int stateId; // State at this transition
+ private IntChoiceFromSet transitionCG; // CG at this transition
+
+ public TransitionEvent() {
+ choice = 0;
+ choiceCounter = 0;
+ execution = null;
+ predecessors = new HashSet<>();
+ stateId = 0;
+ transitionCG = null;
+ }
+
+ public int getChoice() {
+ return choice;
+ }
+
+ public int getChoiceCounter() {
+ return choiceCounter;
+ }
+
+ public Execution getExecution() {
+ return execution;
+ }
+
+ public HashSet<Predecessor> getPredecessors() {
+ return predecessors;
+ }
+
+ public int getStateId() {
+ return stateId;
+ }
+
+ public IntChoiceFromSet getTransitionCG() { return transitionCG; }
+
+ public void recordPredecessor(Execution execution, int choice) {
+ predecessors.add(new Predecessor(choice, execution));
+ }
+
+ public void setChoice(int cho) {
+ choice = cho;
+ }
+
+ public void setChoiceCounter(int choCounter) {
+ choiceCounter = choCounter;
+ }
+
+ public void setExecution(Execution exec) {
+ execution = exec;
+ }
+
+ public void setPredecessors(HashSet<Predecessor> preds) {
+ predecessors = new HashSet<>(preds);
+ }
+
+ public void setStateId(int stId) {
+ stateId = stId;
+ }
+
+ public void setTransitionCG(IntChoiceFromSet cg) {
+ transitionCG = cg;
+ }
+ }
+
// -- CONSTANTS
private final static String DO_CALL_METHOD = "doCall";
// We exclude fields that come from libraries (Java and Groovy), and also the infrastructure
private final static String JAVA_STRING_LIB = "java.lang.String";
// -- FUNCTIONS
- private void fairSchedulingAndTransition(IntChoiceFromSet icsCG, VM vm) {
+ private Integer[] copyChoices(Integer[] choicesToCopy) {
+
+ Integer[] copyOfChoices = new Integer[choicesToCopy.length];
+ System.arraycopy(choicesToCopy, 0, copyOfChoices, 0, choicesToCopy.length);
+ return copyOfChoices;
+ }
+
+ private void ensureFairSchedulingAndSetupTransition(IntChoiceFromSet icsCG, VM vm) {
// Check the next choice and if the value is not the same as the expected then force the expected value
int choiceIndex = choiceCounter % refChoices.length;
int nextChoice = icsCG.getNextChoice();
}
// Get state ID and associate it with this transition
int stateId = vm.getStateId();
+ TransitionEvent transition = setupTransition(icsCG, stateId, choiceIndex);
+ // Add new transition to the current execution and map it in R-Graph
+ for (Integer stId : justVisitedStates) { // Map this transition to all the previously passed states
+ rGraph.addReachableTransition(stId, transition);
+ currentExecution.mapStateToTransition(stId, transition);
+ }
+ currentExecution.mapCGToChoice(icsCG, choiceCounter);
+ // Store restorable state object for this state (always store the latest)
+ RestorableVMState restorableState = vm.getRestorableState();
+ restorableStateMap.put(stateId, restorableState);
+ }
+
+ private TransitionEvent setupTransition(IntChoiceFromSet icsCG, int stateId, int choiceIndex) {
// Get a new transition
TransitionEvent transition;
if (currentExecution.isNew()) {
transition = currentExecution.getFirstTransition();
} else {
transition = new TransitionEvent();
+ currentExecution.addTransition(transition);
transition.recordPredecessor(currentExecution, choiceCounter - 1);
}
transition.setExecution(currentExecution);
transition.setStateId(stateId);
transition.setChoice(refChoices[choiceIndex]);
transition.setChoiceCounter(choiceCounter);
- // Add new transition to the current execution
- currentExecution.mapStateToTransition(stateId, transition);
- currentExecution.addTransition(transition);
- currentExecution.mapCGToChoice(icsCG, choiceCounter);
- // Store restorable state object for this state (always store the latest)
- RestorableVMState restorableState = vm.getRestorableState();
- restorableStateMap.put(stateId, restorableState);
- }
- private Integer[] copyChoices(Integer[] choicesToCopy) {
-
- Integer[] copyOfChoices = new Integer[choicesToCopy.length];
- System.arraycopy(choicesToCopy, 0, copyOfChoices, 0, choicesToCopy.length);
- return copyOfChoices;
+ return transition;
}
// --- Functions related to cycle detection and reachability graph
// 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 completeFullCycle(int stId) {
-
// False if the state ID hasn't been recorded
if (!stateToEventMap.containsKey(stId)) {
return false;
currentExecution = new Execution();
currentExecution.addTransition(new TransitionEvent()); // Always start with 1 backtrack point
doneBacktrackSet = new HashSet<>();
- stateToChoiceCounterMap = new HashMap<>();
- rGraph = new HashMap<>();
+ rGraph = new RGraph();
// Booleans
isEndOfExecution = false;
}
}
}
- // Save the current transition into R-Graph
- // Basically the current transition is reachable from the final state of the previous transition in this execution
- private void addTransitionToRGRaph() {
- // Get the current transition
- TransitionEvent currTrans = currentExecution.getLastTransition();
- // This transition is reachable from this source state when it has advanced the state
- int stateId = currTrans.getStateId();
- // Add transition into R-Graph
- HashSet<TransitionEvent> transitionSet;
- if (rGraph.containsKey(stateId)) {
- transitionSet = rGraph.get(stateId);
- } else {
- transitionSet = new HashSet<>();
- }
- // Insert into the set if it does not contain it yet
- if (!transitionSet.contains(currTrans)) {
- transitionSet.add(currTrans);
- }
- }
-
private boolean terminateCurrentExecution() {
// We need to check all the states that have just been visited
// Often a transition (choice/event) can result into forwarding/backtracking to a number of states
private void updateStateInfo(Search search) {
// Update the state variables
- // Line 19 in the paper page 11 (see the heading note above)
int stateId = search.getStateId();
// Insert state ID into the map if it is new
if (!stateToEventMap.containsKey(stateId)) {
stateToEventMap.put(stateId, eventSet);
}
analyzeReachabilityAndCreateBacktrackPoints(search.getVM(), stateId);
- stateToChoiceCounterMap.put(stateId, choiceCounter);
justVisitedStates.add(stateId);
- currVisitedStates.add(stateId);
+ if (!prevVisitedStates.contains(stateId)) {
+ // It is a currently visited states if the state has not been seen in previous executions
+ currVisitedStates.add(stateId);
+ }
}
// --- Functions related to Read/Write access analysis on shared fields
- private void addNewBacktrackPoint(int stateId, Integer[] newChoiceList, Execution parentExecution, int parentChoice) {
+ private void addNewBacktrackPoint(int stateId, Integer[] newChoiceList, TransitionEvent conflictTransition) {
// Insert backtrack point to the right state ID
LinkedList<BacktrackExecution> backtrackExecList;
if (backtrackMap.containsKey(stateId)) {
}
// Add the new backtrack execution object
TransitionEvent backtrackTransition = new TransitionEvent();
- backtrackTransition.recordPredecessor(parentExecution, parentChoice);
+ backtrackTransition.setPredecessors(conflictTransition.getPredecessors());
backtrackExecList.addFirst(new BacktrackExecution(newChoiceList, backtrackTransition));
// Add to priority queue
if (!backtrackStateQ.contains(stateId)) {
}
// Analyze Read/Write accesses that are directly invoked on fields
- private void analyzeReadWriteAccesses(Instruction executedInsn, String fieldClass, int currentChoice) {
+ private void analyzeReadWriteAccesses(Instruction executedInsn, int currentChoice) {
+ // Get the field info
+ FieldInfo fieldInfo = ((JVMFieldInstruction) executedInsn).getFieldInfo();
+ // Analyze only after being initialized
+ String fieldClass = fieldInfo.getFullName();
// Do the analysis to get Read and Write accesses to fields
ReadWriteSet rwSet = getReadWriteSet(currentChoice);
- int objectId = ((JVMFieldInstruction) executedInsn).getFieldInfo().getClassInfo().getClassObjectRef();
+ int objectId = fieldInfo.getClassInfo().getClassObjectRef();
// Record the field in the map
if (executedInsn instanceof WriteInstruction) {
- // Exclude certain field writes because of infrastructure needs, e.g., Event class field writes
- for (String str : EXCLUDED_FIELDS_READ_WRITE_INSTRUCTIONS_STARTS_WITH_LIST) {
- if (fieldClass.startsWith(str)) {
- return;
+ // We first check the non-relevant fields set
+ if (!nonRelevantFields.contains(fieldInfo)) {
+ // Exclude certain field writes because of infrastructure needs, e.g., Event class field writes
+ for (String str : EXCLUDED_FIELDS_READ_WRITE_INSTRUCTIONS_STARTS_WITH_LIST) {
+ if (fieldClass.startsWith(str)) {
+ nonRelevantFields.add(fieldInfo);
+ return;
+ }
}
+ } else {
+ // If we have this field in the non-relevant fields set then we return right away
+ return;
}
rwSet.addWriteField(fieldClass, objectId);
} else if (executedInsn instanceof ReadInstruction) {
return;
}
// We exclude library classes (they start with java, org, etc.) and some more
- String objClassName = eiAccessObj.getClassInfo().getName();
- if (excludeThisForItStartsWith(EXCLUDED_FIELDS_STARTS_WITH_LIST, objClassName) ||
- excludeThisForItStartsWith(EXCLUDED_FIELDS_READ_WRITE_INSTRUCTIONS_STARTS_WITH_LIST, objClassName)) {
+ ClassInfo classInfo = eiAccessObj.getClassInfo();
+ String objClassName = classInfo.getName();
+ // Check if this class info is part of the non-relevant classes set already
+ if (!nonRelevantClasses.contains(classInfo)) {
+ if (excludeThisForItStartsWith(EXCLUDED_FIELDS_READ_WRITE_INSTRUCTIONS_STARTS_WITH_LIST, objClassName) ||
+ excludeThisForItStartsWith(EXCLUDED_FIELDS_STARTS_WITH_LIST, objClassName)) {
+ nonRelevantClasses.add(classInfo);
+ return;
+ }
+ } else {
+ // If it is part of the non-relevant classes set then return immediately
return;
}
// Extract fields from this object and put them into the read write
return currentChoice;
}
- private void createBacktrackingPoint(Execution execution, int currentChoice, int conflictChoice) {
-
+ private void createBacktrackingPoint(Execution execution, int currentChoice,
+ Execution conflictExecution, int conflictChoice) {
// Create a new list of choices for backtrack based on the current choice and conflicting event number
// E.g. if we have a conflict between 1 and 3, then we create the list {3, 1, 0, 2}
// for the original set {0, 1, 2, 3}
Integer[] newChoiceList = new Integer[refChoices.length];
- //int firstChoice = choices[actualChoice];
- ArrayList<TransitionEvent> pastTrace = execution.getExecutionTrace();
- ArrayList<TransitionEvent> currTrace = currentExecution.getExecutionTrace();
- int currChoice = currTrace.get(currentChoice).getChoice();
- int stateId = pastTrace.get(conflictChoice).getStateId();
+ ArrayList<TransitionEvent> currentTrace = execution.getExecutionTrace();
+ ArrayList<TransitionEvent> conflictTrace = conflictExecution.getExecutionTrace();
+ int currChoice = currentTrace.get(currentChoice).getChoice();
+ int stateId = conflictTrace.get(conflictChoice).getStateId();
// Check if this trace has been done from this state
if (isTraceAlreadyConstructed(currChoice, stateId)) {
return;
j++;
}
}
- // Parent choice is conflict choice - 1
- addNewBacktrackPoint(stateId, newChoiceList, execution, conflictChoice - 1);
+ // Predecessor of the new backtrack point is the same as the conflict point's
+ addNewBacktrackPoint(stateId, newChoiceList, conflictTrace.get(conflictChoice));
}
private boolean excludeThisForItContains(String[] excludedStrings, String className) {
}
private void exploreNextBacktrackPoints(VM vm, IntChoiceFromSet icsCG) {
-
// Check if we are reaching the end of our execution: no more backtracking points to explore
// cgMap, backtrackMap, backtrackStateQ are updated simultaneously (checking backtrackStateQ is enough)
if (!backtrackStateQ.isEmpty()) {
isEndOfExecution = true;
}
- private boolean isConflictFound(Execution execution, int reachableChoice, int conflictChoice,
+ private boolean isConflictFound(Execution execution, int reachableChoice, Execution conflictExecution, int conflictChoice,
ReadWriteSet currRWSet) {
-
ArrayList<TransitionEvent> executionTrace = execution.getExecutionTrace();
- HashMap<Integer, ReadWriteSet> execRWFieldsMap = execution.getReadWriteFieldsMap();
+ ArrayList<TransitionEvent> conflictTrace = conflictExecution.getExecutionTrace();
+ HashMap<Integer, ReadWriteSet> confRWFieldsMap = conflictExecution.getReadWriteFieldsMap();
// Skip if this event does not have any Read/Write set or the two events are basically the same event (number)
- if (!execRWFieldsMap.containsKey(conflictChoice) ||
- executionTrace.get(reachableChoice).getChoice() == executionTrace.get(conflictChoice).getChoice()) {
+ if (!confRWFieldsMap.containsKey(conflictChoice) ||
+ executionTrace.get(reachableChoice).getChoice() == conflictTrace.get(conflictChoice).getChoice()) {
return false;
}
// R/W set of choice/event that may have a potential conflict
- ReadWriteSet evtRWSet = execRWFieldsMap.get(conflictChoice);
+ ReadWriteSet confRWSet = confRWFieldsMap.get(conflictChoice);
// Check for conflicts with Read and Write fields for Write instructions
Set<String> currWriteSet = currRWSet.getWriteSet();
for(String writeField : currWriteSet) {
int currObjId = currRWSet.writeFieldObjectId(writeField);
- if (evtRWSet.readFieldExists(writeField) && evtRWSet.readFieldObjectId(writeField) == currObjId) {
- // Remove this from the read set as we are tracking per memory location
- evtRWSet.removeWriteField(writeField);
- return true;
- } else if (evtRWSet.writeFieldExists(writeField) && evtRWSet.writeFieldObjectId(writeField) == currObjId) {
+ if ((confRWSet.readFieldExists(writeField) && confRWSet.readFieldObjectId(writeField) == currObjId) ||
+ (confRWSet.writeFieldExists(writeField) && confRWSet.writeFieldObjectId(writeField) == currObjId)) {
// Remove this from the write set as we are tracking per memory location
- evtRWSet.removeReadField(writeField);
+ currRWSet.removeWriteField(writeField);
return true;
}
}
Set<String> currReadSet = currRWSet.getReadSet();
for(String readField : currReadSet) {
int currObjId = currRWSet.readFieldObjectId(readField);
- if (evtRWSet.writeFieldExists(readField) && evtRWSet.writeFieldObjectId(readField) == currObjId) {
- // Remove this from the write set as we are tracking per memory location
- evtRWSet.removeWriteField(readField);
- return true;
- }
- }
- // Return false if no conflict is found
- return false;
- }
-
- private boolean isConflictFound(Execution execution, int reachableChoice, int conflictChoice) {
-
- ArrayList<TransitionEvent> executionTrace = execution.getExecutionTrace();
- HashMap<Integer, ReadWriteSet> execRWFieldsMap = execution.getReadWriteFieldsMap();
- // Skip if this event does not have any Read/Write set or the two events are basically the same event (number)
- if (!execRWFieldsMap.containsKey(conflictChoice) ||
- executionTrace.get(reachableChoice).getChoice() == executionTrace.get(conflictChoice).getChoice()) {
- return false;
- }
- // Current R/W set
- ReadWriteSet currRWSet = execRWFieldsMap.get(reachableChoice);
- // R/W set of choice/event that may have a potential conflict
- ReadWriteSet evtRWSet = execRWFieldsMap.get(conflictChoice);
- // Check for conflicts with Read and Write fields for Write instructions
- Set<String> currWriteSet = currRWSet.getWriteSet();
- for(String writeField : currWriteSet) {
- int currObjId = currRWSet.writeFieldObjectId(writeField);
- if ((evtRWSet.readFieldExists(writeField) && evtRWSet.readFieldObjectId(writeField) == currObjId) ||
- (evtRWSet.writeFieldExists(writeField) && evtRWSet.writeFieldObjectId(writeField) == currObjId)) {
- return true;
- }
- }
- // Check for conflicts with Write fields for Read instructions
- Set<String> currReadSet = currRWSet.getReadSet();
- for(String readField : currReadSet) {
- int currObjId = currRWSet.readFieldObjectId(readField);
- if (evtRWSet.writeFieldExists(readField) && evtRWSet.writeFieldObjectId(readField) == currObjId) {
+ if (confRWSet.writeFieldExists(readField) && confRWSet.writeFieldObjectId(readField) == currObjId) {
+ // Remove this from the read set as we are tracking per memory location
+ currRWSet.removeReadField(readField);
return true;
}
}
return rwSet;
}
- private boolean isFieldExcluded(String field) {
+ private boolean isFieldExcluded(Instruction executedInsn) {
+ // Get the field info
+ FieldInfo fieldInfo = ((JVMFieldInstruction) executedInsn).getFieldInfo();
+ // Check if the non-relevant fields set already has it
+ if (nonRelevantFields.contains(fieldInfo)) {
+ return true;
+ }
+ // Check if the relevant fields set already has it
+ if (relevantFields.contains(fieldInfo)) {
+ return false;
+ }
+ // Analyze only after being initialized
+ String field = fieldInfo.getFullName();
// Check against "starts-with", "ends-with", and "contains" list
if (excludeThisForItStartsWith(EXCLUDED_FIELDS_STARTS_WITH_LIST, field) ||
excludeThisForItEndsWith(EXCLUDED_FIELDS_ENDS_WITH_LIST, field) ||
excludeThisForItContains(EXCLUDED_FIELDS_CONTAINS_LIST, field)) {
+ nonRelevantFields.add(fieldInfo);
return true;
}
-
+ relevantFields.add(fieldInfo);
return false;
}
refChoices = copyChoices(choices);
// Clear data structures
currVisitedStates = new HashSet<>();
- stateToChoiceCounterMap = new HashMap<>();
stateToEventMap = new HashMap<>();
isEndOfExecution = false;
}
// 1) recursively, and
// 2) track accesses per memory location (per shared variable/field)
private void updateBacktrackSet(Execution execution, int currentChoice) {
- // Choice/event we want to check for conflict against (start from actual choice)
- int conflictChoice = currentChoice;
// Copy ReadWriteSet object
HashMap<Integer, ReadWriteSet> currRWFieldsMap = execution.getReadWriteFieldsMap();
- ReadWriteSet currRWSet = currRWFieldsMap.get(currentChoice).getCopy();
+ ReadWriteSet currRWSet = currRWFieldsMap.get(currentChoice);
+ if (currRWSet == null) {
+ return;
+ }
+ currRWSet = currRWSet.getCopy();
// Memorize visited TransitionEvent object while performing backward DFS to avoid getting caught up in a cycle
HashSet<TransitionEvent> visited = new HashSet<>();
// Update backtrack set recursively
- updateBacktrackSetRecursive(execution, currentChoice, conflictChoice, currRWSet, visited);
+ // TODO: The following is the call to the original version of the method
+// updateBacktrackSetRecursive(execution, currentChoice, execution, currentChoice, currRWSet, visited);
+ // TODO: The following is the call to the version of the method with pushing up happens-before transitions
+ updateBacktrackSetRecursive(execution, currentChoice, execution, currentChoice, execution, currentChoice, currRWSet, visited);
}
- private void updateBacktrackSetRecursive(Execution execution, int currentChoice, int conflictChoice,
+// TODO: This is the original version of the recursive method
+// private void updateBacktrackSetRecursive(Execution execution, int currentChoice,
+// Execution conflictExecution, int conflictChoice,
+// ReadWriteSet currRWSet, HashSet<TransitionEvent> visited) {
+// // Halt when we have found the first read/write conflicts for all memory locations
+// if (currRWSet.isEmpty()) {
+// return;
+// }
+// TransitionEvent confTrans = conflictExecution.getExecutionTrace().get(conflictChoice);
+// // Halt when we have visited this transition (in a cycle)
+// if (visited.contains(confTrans)) {
+// return;
+// }
+// visited.add(confTrans);
+// // Explore all predecessors
+// for (Predecessor predecessor : confTrans.getPredecessors()) {
+// // Get the predecessor (previous conflict choice)
+// conflictChoice = predecessor.getChoice();
+// conflictExecution = predecessor.getExecution();
+// // Check if a conflict is found
+// if (isConflictFound(execution, currentChoice, conflictExecution, conflictChoice, currRWSet)) {
+// createBacktrackingPoint(execution, currentChoice, conflictExecution, conflictChoice);
+// }
+// // Continue performing DFS if conflict is not found
+// updateBacktrackSetRecursive(execution, currentChoice, conflictExecution, conflictChoice, currRWSet, visited);
+// }
+// }
+
+ // TODO: This is the version of the method with pushing up happens-before transitions
+ private void updateBacktrackSetRecursive(Execution execution, int currentChoice,
+ Execution conflictExecution, int conflictChoice,
+ Execution hbExecution, int hbChoice,
ReadWriteSet currRWSet, HashSet<TransitionEvent> visited) {
// Halt when we have found the first read/write conflicts for all memory locations
if (currRWSet.isEmpty()) {
return;
}
- TransitionEvent confTrans = execution.getExecutionTrace().get(conflictChoice);
+ TransitionEvent confTrans = conflictExecution.getExecutionTrace().get(conflictChoice);
// Halt when we have visited this transition (in a cycle)
if (visited.contains(confTrans)) {
return;
// Explore all predecessors
for (Predecessor predecessor : confTrans.getPredecessors()) {
// Get the predecessor (previous conflict choice)
- conflictChoice = predecessor.getPredecessorChoice();
- execution = predecessor.getPredecessorExecution();
+ conflictChoice = predecessor.getChoice();
+ conflictExecution = predecessor.getExecution();
+ // Push up one happens-before transition
+ int pushedChoice = hbChoice;
+ Execution pushedExecution = hbExecution;
// Check if a conflict is found
- if (isConflictFound(execution, currentChoice, conflictChoice, currRWSet)) {
- createBacktrackingPoint(execution, currentChoice, conflictChoice);
+ if (isConflictFound(execution, currentChoice, conflictExecution, conflictChoice, currRWSet)) {
+ createBacktrackingPoint(pushedExecution, pushedChoice, conflictExecution, conflictChoice);
+ pushedChoice = conflictChoice;
+ pushedExecution = conflictExecution;
}
// Continue performing DFS if conflict is not found
- updateBacktrackSetRecursive(execution, currentChoice, conflictChoice, currRWSet, visited);
+ updateBacktrackSetRecursive(execution, currentChoice, conflictExecution, conflictChoice,
+ pushedExecution, pushedChoice, currRWSet, visited);
}
}
private void analyzeReachabilityAndCreateBacktrackPoints(VM vm, int stateId) {
// Perform this analysis only when:
- // 1) there is a state match,
- // 2) this is not during a switch to a new execution,
- // 3) at least 2 choices/events have been explored (choiceCounter > 1),
- // 4) state > 0 (state 0 is for boolean CG)
- if (!vm.isNewState() && !isEndOfExecution && choiceCounter > 1 && (stateId > 0)) {
+ // 1) this is not during a switch to a new execution,
+ // 2) at least 2 choices/events have been explored (choiceCounter > 1),
+ // 3) state > 0 (state 0 is for boolean CG)
+ if (!isEndOfExecution && choiceCounter > 1 && stateId > 0) {
if (currVisitedStates.contains(stateId)) {
// Get the backtrack point from the current execution
TransitionEvent transition = currentExecution.getTransitionFromState(stateId);
updateBacktrackSetsFromPreviousExecution(stateId);
} else if (prevVisitedStates.contains(stateId)) { // We visit a state in a previous execution
// Update past executions with a predecessor
- HashSet<TransitionEvent> reachableTransitions = rGraph.get(stateId);
+ HashSet<TransitionEvent> reachableTransitions = rGraph.getReachableTransitionsAtState(stateId);
for(TransitionEvent transition : reachableTransitions) {
- Execution execution = transition.getExecution();
- transition.recordPredecessor(execution, choiceCounter - 1);
+ transition.recordPredecessor(currentExecution, choiceCounter - 1);
}
updateBacktrackSetsFromPreviousExecution(stateId);
}
// Update the backtrack sets from previous executions
private void updateBacktrackSetsFromPreviousExecution(int stateId) {
// Collect all the reachable transitions from R-Graph
- HashSet<TransitionEvent> reachableTransitions = rGraph.get(stateId);
+ HashSet<TransitionEvent> reachableTransitions = rGraph.getReachableTransitions(stateId);
for(TransitionEvent transition : reachableTransitions) {
Execution execution = transition.getExecution();
int currentChoice = transition.getChoiceCounter();
projects / jpf-core.git / blobdiff