From 8307c84256b8574dc03b6f0c7a3d4084acdeabc7 Mon Sep 17 00:00:00 2001 From: rtrimana Date: Tue, 12 Nov 2019 13:32:02 -0800 Subject: [PATCH] Checking in (1) StateReducer, and (2) StateReducerEfficient; ISSUE: the StateReducerEfficient doesn't traverse the sub-graphs completely and JPF ignores some of the child CGs---incomplete POR. --- .../gov/nasa/jpf/listener/StateReducer.java | 2 +- .../jpf/listener/StateReducerEfficient.java | 529 ++++++++++++++++++ 2 files changed, 530 insertions(+), 1 deletion(-) create mode 100644 src/main/gov/nasa/jpf/listener/StateReducerEfficient.java diff --git a/src/main/gov/nasa/jpf/listener/StateReducer.java b/src/main/gov/nasa/jpf/listener/StateReducer.java index 08b27b1..4667668 100644 --- a/src/main/gov/nasa/jpf/listener/StateReducer.java +++ b/src/main/gov/nasa/jpf/listener/StateReducer.java @@ -509,4 +509,4 @@ public class StateReducer extends ListenerAdapter { } } } -} \ No newline at end of file +} diff --git a/src/main/gov/nasa/jpf/listener/StateReducerEfficient.java b/src/main/gov/nasa/jpf/listener/StateReducerEfficient.java new file mode 100644 index 0000000..ebe9201 --- /dev/null +++ b/src/main/gov/nasa/jpf/listener/StateReducerEfficient.java @@ -0,0 +1,529 @@ +/* + * Copyright (C) 2014, United States Government, as represented by the + * Administrator of the National Aeronautics and Space Administration. + * All rights reserved. + * + * The Java Pathfinder core (jpf-core) platform is licensed under the + * Apache License, Version 2.0 (the "License"); you may not use this file except + * in compliance with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0. + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package gov.nasa.jpf.listener; + +import gov.nasa.jpf.Config; +import gov.nasa.jpf.JPF; +import gov.nasa.jpf.ListenerAdapter; +import gov.nasa.jpf.search.Search; +import gov.nasa.jpf.jvm.bytecode.*; +import gov.nasa.jpf.vm.*; +import gov.nasa.jpf.vm.bytecode.ReadInstruction; +import gov.nasa.jpf.vm.bytecode.WriteInstruction; +import gov.nasa.jpf.vm.choice.IntChoiceFromSet; + +import java.io.PrintWriter; + +import java.util.*; + +// TODO: Fix for Groovy's model-checking +// TODO: This is a setter to change the values of the ChoiceGenerator to implement POR + +// TODO: ISSUES +// TODO: This POR implementation, however, has some issues in that the DFS algorithm doesn't properly +// traverse the sub-graphs after resets (the CGs are ignored) +/** + * simple tool to log state changes + */ +public class StateReducerEfficient extends ListenerAdapter { + + // Debug info fields + private boolean debugMode; + private boolean stateReductionMode; + private final PrintWriter out; + volatile private String detail; + volatile private int depth; + volatile private int id; + Transition transition; + + // State reduction fields + private Integer[] choices; + private IntChoiceFromSet currCG; + private int choiceCounter; + private Integer choiceUpperBound; + private boolean isInitialized; + private HashMap resetAfterAnalysisMap; + private HashMap cgToParentChoicesMap; + private HashMap> choicesToCGMap; + private HashMap>> choicesToBacktrackMap; + private boolean isBooleanCGFlipped; + // Record the mapping between event number and field accesses (Read and Write) + private HashMap readWriteFieldsMap; + // The following is the backtrack map (set) that stores all the backtrack information + // e.g., event number 1 can have two backtrack sequences: {3,1,2,4,...} and {2,1,3,4,...} + private HashMap> conflictPairMap; + + public StateReducerEfficient (Config config, JPF jpf) { + debugMode = config.getBoolean("debug_state_transition", false); + stateReductionMode = config.getBoolean("activate_state_reduction", true); + if (debugMode) { + out = new PrintWriter(System.out, true); + } else { + out = null; + } + detail = null; + depth = 0; + id = 0; + transition = null; + isBooleanCGFlipped = false; + // TODO: TESTING + choicesToCGMap = new HashMap<>(); + choicesToBacktrackMap = new HashMap<>(); + resetAfterAnalysisMap = new HashMap<>(); + resetAfterAnalysisMap.put(null, false); + cgToParentChoicesMap = new HashMap<>(); + readWriteFieldsMap = new HashMap<>(); + conflictPairMap = new HashMap<>(); + choices = null; + currCG = null; + choiceCounter = 0; + initializeStateReduction(); + } + + private void initializeStateReduction() { + choiceUpperBound = 0; + isInitialized = false; + readWriteFieldsMap.clear(); + conflictPairMap.clear(); + } + + @Override + public void stateRestored(Search search) { + if (debugMode) { + id = search.getStateId(); + depth = search.getDepth(); + transition = search.getTransition(); + detail = null; + out.println("\n==> DEBUG: The state is restored to state with id: " + id + " -- Transition: " + transition + + " and depth: " + depth + "\n"); + } + } + + //--- the ones we are interested in + @Override + public void searchStarted(Search search) { + if (debugMode) { + out.println("\n==> DEBUG: ----------------------------------- search started" + "\n"); + } + } + + // We map current child CG to parent CG + private void insertCGToMap(int choice, IntChoiceFromSet childCG) { + HashMap cgMap; + if (choicesToCGMap.containsKey(choices)) { + cgMap = choicesToCGMap.get(choices); + } else { + cgMap = new HashMap<>(); + } + cgMap.put(childCG, choice); + choicesToCGMap.put(choices,cgMap); + } + + @Override + public void choiceGeneratorRegistered (VM vm, ChoiceGenerator nextCG, ThreadInfo currentThread, Instruction executedInstruction) { + if (stateReductionMode) { + // Initialize with necessary information from the CG + if (nextCG instanceof IntChoiceFromSet) { + IntChoiceFromSet icsCG = (IntChoiceFromSet) nextCG; + // Check if CG has been initialized, otherwise initialize it + Integer[] cgChoices = null; + if (!isInitialized) { + if (currCG == null) { // Main + cgChoices = icsCG.getAllChoices(); + // Get the upper bound from the last element of the choices + choiceUpperBound = cgChoices.length - 1; + } else { // Sub-graph + cgChoices = choices; + choiceUpperBound = cgChoices.length - 2; + } + isInitialized = true; + } + // Record the subsequent Integer CGs only until we hit the upper bound + boolean isResetAfterAnalysis = resetAfterAnalysisMap.get(currCG); + if (!isResetAfterAnalysis && choiceCounter <= choiceUpperBound) { + // Update the choices of the first CG and add '-1' + if (choices == null) { + // 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; + } + 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]); + insertCGToMap(choices[choiceCounter], icsCG); + choiceCounter++; + cgToParentChoicesMap.put(icsCG, choices); + } else { + // Set done the subsequent CGs + // We only need n CGs (n is event numbers) + icsCG.setDone(); + } + } + } + } + + private void resetAllCGs() { + HashMap> currBacktrackMap = choicesToBacktrackMap.get(choices); + if (currBacktrackMap == null) { + return; + } + // Extract the event numbers that have backtrack lists + Set eventSet = currBacktrackMap.keySet(); + // Return if there is no conflict at all (highly unlikely) + if (eventSet.isEmpty()) { + return; + } + // Reset every CG with the first backtrack lists + HashMap currCGMap = choicesToCGMap.get(choices); + for(IntChoiceFromSet cg : currCGMap.keySet()) { + int event = currCGMap.get(cg); + LinkedList choiceLists = currBacktrackMap.get(event); + if (choiceLists != null && choiceLists.peekFirst() != null) { + Integer[] choiceList = choiceLists.removeFirst(); + // Deploy the new choice list for this CG + cg.setNewValues(choiceList); + cg.reset(); + } else { + cg.setDone(); + } + } + } + + @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 (!isBooleanCGFlipped) { + isBooleanCGFlipped = true; + } else { + choiceCounter = 0; + initializeStateReduction(); + } + } + // Check every choice generated and make sure that all the available choices + // are chosen first before repeating the same choice of value twice! + 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(); + resetAfterAnalysisMap.put(icsCG, false); + choiceCounter = 1; + // Reset states for the sub-graph + initializeStateReduction(); + } + if (icsCG.getNextChoice() == -1) { + // Get the current CG + boolean isCurrResetAfterAnalysis = resetAfterAnalysisMap.get(currCG); + // Update and reset the CG if needed (do this for the first time after the analysis) + if (!isCurrResetAfterAnalysis) { + resetAllCGs(); + resetAfterAnalysisMap.put(currCG, true); + } + if (!icsCG.isDone()) { + // Get the CG that needs to be reset + Integer[] parentChoices = cgToParentChoicesMap.get(icsCG); + // Do this for every CG after finishing each backtrack list + HashMap parentCGMap = choicesToCGMap.get(parentChoices); + HashMap> parentBacktrackMap = choicesToBacktrackMap.get(parentChoices); + int event = parentCGMap.get(icsCG); + LinkedList choiceLists = parentBacktrackMap.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(); + } + } + } + } + } + } + + @Override + public void stateAdvanced(Search search) { + if (debugMode) { + id = search.getStateId(); + depth = search.getDepth(); + transition = search.getTransition(); + if (search.isNewState()) { + detail = "new"; + } else { + detail = "visited"; + } + + if (search.isEndState()) { + out.println("\n==> DEBUG: This is the last state!\n"); + detail += " end"; + } + out.println("\n==> DEBUG: The state is forwarded to state with id: " + id + " with depth: " + depth + + " which is " + detail + " Transition: " + transition + "\n"); + } + } + + @Override + public void stateBacktracked(Search search) { + if (debugMode) { + id = search.getStateId(); + depth = search.getDepth(); + transition = search.getTransition(); + detail = null; + + out.println("\n==> DEBUG: The state is backtracked to state with id: " + id + " -- Transition: " + transition + + " and depth: " + depth + "\n"); + } + } + + @Override + public void searchFinished(Search search) { + if (debugMode) { + out.println("\n==> DEBUG: ----------------------------------- search finished" + "\n"); + } + } + + // This class compactly stores Read and Write field sets + // We store the field name and its object ID + // Sharing the same field means the same field name and object ID + private class ReadWriteSet { + private HashMap readSet; + private HashMap writeSet; + + public ReadWriteSet() { + readSet = new HashMap<>(); + writeSet = new HashMap<>(); + } + + public void addReadField(String field, int objectId) { + readSet.put(field, objectId); + } + + public void addWriteField(String field, int objectId) { + writeSet.put(field, objectId); + } + + public boolean readFieldExists(String field) { + return readSet.containsKey(field); + } + + public boolean writeFieldExists(String field) { + return writeSet.containsKey(field); + } + + public int readFieldObjectId(String field) { + return readSet.get(field); + } + + public int writeFieldObjectId(String field) { + return writeSet.get(field); + } + } + + private void analyzeReadWriteAccesses(Instruction executedInsn, String fieldClass, int currentChoice) { + // Do the analysis to get Read and Write accesses to fields + ReadWriteSet rwSet; + // We already have an entry + if (readWriteFieldsMap.containsKey(choices[currentChoice])) { + rwSet = readWriteFieldsMap.get(choices[currentChoice]); + } else { // We need to create a new entry + rwSet = new ReadWriteSet(); + readWriteFieldsMap.put(choices[currentChoice], rwSet); + } + int objectId = ((JVMFieldInstruction) executedInsn).getFieldInfo().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_WRITE_INSTRUCTIONS_STARTS_WITH_LIST) { + if (fieldClass.startsWith(str)) { + return; + } + } + rwSet.addWriteField(fieldClass, objectId); + } else if (executedInsn instanceof ReadInstruction) { + rwSet.addReadField(fieldClass, objectId); + } + } + + private boolean recordConflictPair(int currentEvent, int eventNumber) { + HashSet conflictSet; + if (!conflictPairMap.containsKey(currentEvent)) { + conflictSet = new HashSet<>(); + conflictPairMap.put(currentEvent, conflictSet); + } else { + conflictSet = conflictPairMap.get(currentEvent); + } + // If this conflict has been recorded before, we return false because + // we don't want to service this backtrack point twice + if (conflictSet.contains(eventNumber)) { + return false; + } + // If it hasn't been recorded, then do otherwise + conflictSet.add(eventNumber); + return true; + } + + private void createBacktrackChoiceList(int currentChoice, int conflictEventNumber) { + + LinkedList backtrackChoiceLists; + // Create a new list of choices for backtrack based on the current choice and conflicting event number + // If we have a conflict between 1 and 3, then we create the list {3, 1, 2, 4, 5} for backtrack + // The backtrack point is the CG for event number 1 and the list length is one less than the original list + // (originally of length 6) since we don't start from event number 0 + boolean isResetAfterAnalysis = resetAfterAnalysisMap.get(currCG); + if (!isResetAfterAnalysis) { + HashMap> currBacktrackMap; + if (!choicesToBacktrackMap.containsKey(choices)) { + currBacktrackMap = new HashMap<>(); + choicesToBacktrackMap.put(choices, currBacktrackMap); + } else { + currBacktrackMap = choicesToBacktrackMap.get(choices); + } + // Check if we have a list for this choice number + // If not we create a new one for it + if (!currBacktrackMap.containsKey(conflictEventNumber)) { + backtrackChoiceLists = new LinkedList<>(); + currBacktrackMap.put(conflictEventNumber, backtrackChoiceLists); + } else { + backtrackChoiceLists = currBacktrackMap.get(conflictEventNumber); + } + int maxListLength = choiceUpperBound + 1; + int listLength = maxListLength - conflictEventNumber; + Integer[] newChoiceList = new Integer[listLength + 1]; + // Put the conflicting event numbers first and reverse the order + newChoiceList[0] = choices[currentChoice]; + newChoiceList[1] = choices[conflictEventNumber]; + // Put the rest of the event numbers into the array starting from the minimum to the upper bound + for (int i = conflictEventNumber + 1, j = 2; j < listLength; i++) { + if (choices[i] != choices[currentChoice]) { + newChoiceList[j] = choices[i]; + j++; + } + } + // Set the last element to '-1' as the end of the sequence + newChoiceList[newChoiceList.length - 1] = -1; + backtrackChoiceLists.addLast(newChoiceList); + } + } + + // We exclude fields that come from libraries (Java and Groovy), and also the infrastructure + private final static String[] EXCLUDED_FIELDS_STARTS_WITH_LIST = + // Java and Groovy libraries + { "java", "org", "sun", "com", "gov", "groovy"}; + private final static String[] EXCLUDED_FIELDS_ENDS_WITH_LIST = + // Groovy library created fields + {"stMC", "callSiteArray", "metaClass", "staticClassInfo", "__constructor__", + // Infrastructure + "sendEvent", "Object", "reference", "location", "app", "state", "log", "functionList", "objectList", + "eventList", "valueList", "settings", "printToConsole", "app1", "app2"}; + private final static String[] EXCLUDED_FIELDS_CONTAINS_LIST = {"_closure"}; + private final static String[] EXCLUDED_FIELDS_WRITE_INSTRUCTIONS_STARTS_WITH_LIST = {"Event"}; + + private boolean isFieldExcluded(String field) { + // Check against "starts-with" list + for(String str : EXCLUDED_FIELDS_STARTS_WITH_LIST) { + if (field.startsWith(str)) { + return true; + } + } + // Check against "ends-with" list + for(String str : EXCLUDED_FIELDS_ENDS_WITH_LIST) { + if (field.endsWith(str)) { + return true; + } + } + // Check against "contains" list + for(String str : EXCLUDED_FIELDS_CONTAINS_LIST) { + if (field.contains(str)) { + return true; + } + } + + return false; + } + + @Override + public void instructionExecuted(VM vm, ThreadInfo ti, Instruction nextInsn, Instruction executedInsn) { + if (stateReductionMode) { + if (isInitialized) { + if (choiceCounter > choices.length - 1) { + // 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 + String fieldClass = ((JVMFieldInstruction) executedInsn).getFieldInfo().getFullName(); + // We don't care about libraries + if (!isFieldExcluded(fieldClass)) { + analyzeReadWriteAccesses(executedInsn, fieldClass, currentChoice); + } + } + // Analyze conflicts from next instructions + if (nextInsn instanceof JVMFieldInstruction) { + // The constructor is only called once when the object is initialized + // It does not have shared access with other objects + MethodInfo mi = nextInsn.getMethodInfo(); + if (!mi.getName().equals("")) { + String fieldClass = ((JVMFieldInstruction) nextInsn).getFieldInfo().getFullName(); + // We don't care about libraries + if (!isFieldExcluded(fieldClass)) { + // For the main graph we go down to 0, but for subgraph, we only go down to 1 since 0 contains + // the reversed event + // If null then it is the main graph, if not it is a sub-graph + int end = currCG == null ? 0 : 1; + // Check for conflict (go backward from currentChoice and get the first conflict) + // If the current event has conflicts with multiple events, then these will be detected + // one by one as this recursively checks backward when backtrack set is revisited and executed. + for (int eventNumber = currentChoice - 1; eventNumber >= end; eventNumber--) { + // Skip if this event number does not have any Read/Write set + if (!readWriteFieldsMap.containsKey(choices[eventNumber])) { + continue; + } + ReadWriteSet rwSet = readWriteFieldsMap.get(choices[eventNumber]); + int currObjId = ((JVMFieldInstruction) nextInsn).getFieldInfo().getClassInfo().getClassObjectRef(); + // 1) Check for conflicts with Write fields for both Read and Write instructions + // 2) Check for conflicts with Read fields for Write instructions + if (((nextInsn instanceof WriteInstruction || nextInsn instanceof ReadInstruction) && + rwSet.writeFieldExists(fieldClass) && rwSet.writeFieldObjectId(fieldClass) == currObjId) || + (nextInsn instanceof WriteInstruction && rwSet.readFieldExists(fieldClass) && + rwSet.readFieldObjectId(fieldClass) == currObjId)) { + // We do not record and service the same backtrack pair/point twice! + // If it has been serviced before, we just skip this + if (recordConflictPair(currentChoice, eventNumber)) { + createBacktrackChoiceList(currentChoice, eventNumber); + // Break if a conflict is found! + break; + } + } + } + } + } + } + } + } + } +} -- 2.34.1