+/*
+ * 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.LocalVariableInstruction;
+import gov.nasa.jpf.vm.bytecode.ReadInstruction;
+import gov.nasa.jpf.vm.bytecode.StoreInstruction;
+import gov.nasa.jpf.vm.bytecode.WriteInstruction;
+
+import java.io.PrintWriter;
+
+import java.util.*;
+
+/**
+ * Listener using data flow analysis to find conflicts between smartApps.
+ **/
+
+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 HashMap<Integer, ArrayList<Integer>> predSet = new HashMap<Integer, ArrayList<Integer>>();
+ private final HashMap<Integer, ArrayList<Integer>> succSet = new HashMap<Integer, ArrayList<Integer>>();
+ private final HashMap<Integer, DataSet> setSet = new HashMap<Integer, DataSet>();
+ private final HashMap<Integer, DataSet> inSet = new HashMap<Integer, DataSet>();
+ private final HashMap<Integer, DataSet> outSet = new HashMap<Integer, DataSet>();
+ volatile private String operation;
+ volatile private String detail;
+ volatile private int depth;
+ volatile private int id;
+ volatile private int parentId = -2;
+ volatile private int conflictFound = 0;
+ Transition transition;
+ Object annotation;
+ String label;
+
+
+ public ConflictTracker(Config conf, JPF jpf) {
+ out = new PrintWriter(System.out, true);
+
+ String[] conflictVars = conf.getStringArray("variables");
+ // We are not tracking anything if it is null
+ if (conflictVars != null) {
+ for (String var : conflictVars) {
+ conflictSet.add(var);
+ }
+ }
+ String[] apps = conf.getStringArray("apps");
+ // We are not tracking anything if it is null
+ if (apps != null) {
+ for (String var : apps) {
+ appSet.add(var);
+ }
+ }
+ }
+
+ class DataList {
+ boolean appSet;
+ String value;
+
+ DataList(boolean appSet, String value) {
+ this.appSet = appSet;
+ this.value = value;
+ }
+ }
+
+ class DataSet {
+ HashMap<Integer, DataList> dataSet = new HashMap<Integer, DataList>();
+
+ DataSet(HashMap<Integer, DataList> dataSet) {
+ this.dataSet = dataSet;
+ }
+ }
+
+ @Override
+ public void stateRestored(Search search) {
+ id = search.getStateId();
+ depth = search.getDepth();
+ operation = "restored";
+ detail = null;
+
+ out.println("The state is restored to state with id: "+id+", depth: "+depth);
+
+ parentId = id;
+ }
+
+ @Override
+ public void searchStarted(Search search) {
+ out.println("----------------------------------- search started");
+ }
+
+ @Override
+ public void stateAdvanced(Search search) {
+ String theEnd = null;
+ id = search.getStateId();
+ depth = search.getDepth();
+ operation = "forward";
+
+ if (search.isNewState()) {
+ detail = "new";
+ } else {
+ detail = "visited";
+ }
+
+ if (search.isEndState()) {
+ out.println("This is the last state!");
+ theEnd = "end";
+ }
+
+ out.println("The state is forwarded to state with id: "+id+", depth: "+depth+" which is "+detail+" state: "+"% "+theEnd);
+
+
+ //Set input set of this state to empty!
+ HashMap<Integer, DataList> inDataSet = new HashMap<Integer, DataList>();
+ inDataSet.put(0, new DataList(false, "NA"));
+ inDataSet.put(1, new DataList(false, "NA"));
+ DataSet inTempDataSet = new DataSet(inDataSet);
+ inSet.put(id, inTempDataSet);
+
+ //Set output set of this state to empty if it is not initialized!
+ if (!outSet.containsKey(id)) {
+ HashMap<Integer, DataList> outDataSet = new HashMap<Integer, DataList>();
+ outDataSet.put(0, new DataList(false, "NA"));
+ outDataSet.put(1, new DataList(false, "NA"));
+ DataSet outTempDataSet = new DataSet(outDataSet);
+ outSet.put(id, outTempDataSet);
+ }
+
+ //Create a temp data set of out set of this node
+ DataList tempDataList1 = new DataList(outSet.get(id).dataSet.get(0).appSet, outSet.get(id).dataSet.get(0).value);
+ DataList tempDataList2 = new DataList(outSet.get(id).dataSet.get(1).appSet, outSet.get(id).dataSet.get(1).value);
+ HashMap<Integer, DataList> tempOutDataSet = new HashMap<Integer, DataList>();
+ tempOutDataSet.put(0, tempDataList1);
+ tempOutDataSet.put(1, tempDataList2);
+ DataSet tempDataSet = new DataSet(tempOutDataSet);
+
+ //Set input set according to output set of pred states of current state
+ if (predSet.containsKey(id)) {
+ for (Integer i : predSet.get(id)) {
+ if ((outSet.get(i).dataSet.get(0).appSet == true)||(inSet.get(id).dataSet.get(0).appSet == true)) {
+ inSet.get(id).dataSet.get(0).appSet = true;
+ inSet.get(id).dataSet.get(0).value = outSet.get(i).dataSet.get(0).value;
+ }
+ if ((outSet.get(i).dataSet.get(1).appSet == true)||(inSet.get(id).dataSet.get(1).appSet == true)) {
+ inSet.get(id).dataSet.get(1).appSet = true;
+ inSet.get(id).dataSet.get(1).value = outSet.get(i).dataSet.get(1).value;
+ }
+ }
+ }
+
+ //Set output set to inset or setSet
+ if (setSet.containsKey(id)) {
+ if ((setSet.get(id).dataSet.get(0).appSet == true)&&(setSet.get(id).dataSet.get(1).appSet == true)) { //App1 & App2 are writers
+ outSet.get(id).dataSet.get(0).appSet = true;
+ outSet.get(id).dataSet.get(0).value = setSet.get(id).dataSet.get(0).value;
+ outSet.get(id).dataSet.get(1).appSet = true;
+ outSet.get(id).dataSet.get(1).value = setSet.get(id).dataSet.get(1).value;
+ } else if (setSet.get(id).dataSet.get(0).appSet == true) { //App1 is a writer
+ outSet.get(id).dataSet.get(0).appSet = true;
+ outSet.get(id).dataSet.get(0).value = setSet.get(id).dataSet.get(0).value;
+ outSet.get(id).dataSet.get(1).appSet = inSet.get(id).dataSet.get(1).appSet;
+ outSet.get(id).dataSet.get(1).value = inSet.get(id).dataSet.get(1).value;
+ } else if (setSet.get(id).dataSet.get(1).appSet == true) { //App2 is a writer
+ outSet.get(id).dataSet.get(0).appSet = inSet.get(id).dataSet.get(0).appSet;
+ outSet.get(id).dataSet.get(0).value = inSet.get(id).dataSet.get(0).value;
+ outSet.get(id).dataSet.get(1).appSet = true;
+ outSet.get(id).dataSet.get(1).value = setSet.get(id).dataSet.get(1).value;
+ }
+ } else {
+ outSet.get(id).dataSet.get(0).appSet = inSet.get(id).dataSet.get(0).appSet;
+ outSet.get(id).dataSet.get(0).value = inSet.get(id).dataSet.get(0).value;
+ outSet.get(id).dataSet.get(1).appSet = inSet.get(id).dataSet.get(1).appSet;
+ outSet.get(id).dataSet.get(1).value = inSet.get(id).dataSet.get(1).value;
+ }
+
+ if ((outSet.get(id).dataSet.get(0).appSet == true)&&(outSet.get(id).dataSet.get(1).appSet == true)) { //Both apps have set the device
+ if (!(outSet.get(id).dataSet.get(0).value.equals(outSet.get(id).dataSet.get(1).value))) //Values set by the apps are not the same, and we have a conflict!
+ conflictFound = 1;
+ }
+
+ if ((outSet.get(id).dataSet.get(0).appSet != tempDataSet.dataSet.get(0).appSet)||
+ ((!outSet.get(id).dataSet.get(0).value.equals(tempDataSet.dataSet.get(0).value)))||
+ (outSet.get(id).dataSet.get(1).appSet != tempDataSet.dataSet.get(1).appSet)||
+ ((!outSet.get(id).dataSet.get(1).value.equals(tempDataSet.dataSet.get(1).value)))) {
+ ArrayList<Integer> changed = new ArrayList<Integer>(predSet.get(id));
+ while(!changed.isEmpty()) {
+ //Get a random node inside the changed list!
+ Integer rnd = new Random().nextInt(changed.size());
+ Integer nodeToProcess = changed.get(rnd);
+ changed.remove(nodeToProcess);
+
+ //Initialize the empty input set for the current node
+ HashMap<Integer, DataList> nodeDataSet = new HashMap<Integer, DataList>();
+ nodeDataSet.put(0, new DataList(false, "NA"));
+ nodeDataSet.put(1, new DataList(false, "NA"));
+ DataSet nodeTempDataSet = new DataSet(nodeDataSet);
+ inSet.put(nodeToProcess, nodeTempDataSet);
+
+ //Store current output to temp dataset
+ HashMap<Integer, DataList> currentOutDataSet = new HashMap<Integer, DataList>();
+ currentOutDataSet.put(0, new DataList(outSet.get(nodeToProcess).dataSet.get(0).appSet, outSet.get(nodeToProcess).dataSet.get(0).value));
+ currentOutDataSet.put(1, new DataList(outSet.get(nodeToProcess).dataSet.get(1).appSet, outSet.get(nodeToProcess).dataSet.get(1).value));
+ DataSet currentDataSet = new DataSet(currentOutDataSet);
+
+ //Update the in set based on predecessors
+ for (Integer i : predSet.get(nodeToProcess)) {
+ if ((outSet.get(i).dataSet.get(0).appSet == true)||(inSet.get(nodeToProcess).dataSet.get(0).appSet == true)) {
+ inSet.get(nodeToProcess).dataSet.get(0).appSet = true;
+ inSet.get(nodeToProcess).dataSet.get(0).value = outSet.get(i).dataSet.get(0).value;
+ }
+
+ if ((outSet.get(i).dataSet.get(1).appSet == true)||(inSet.get(nodeToProcess).dataSet.get(1).appSet == true)) {
+ inSet.get(nodeToProcess).dataSet.get(1).appSet = true;
+ inSet.get(nodeToProcess).dataSet.get(1).value = outSet.get(i).dataSet.get(1).value;
+ }
+ }
+
+ //Set output set to inset or setSet
+ if (setSet.containsKey(nodeToProcess)) {
+ if ((setSet.get(nodeToProcess).dataSet.get(0).appSet == true)&&(setSet.get(nodeToProcess).dataSet.get(1).appSet == true)) { //App1 & App2 are writers
+ outSet.get(nodeToProcess).dataSet.get(0).appSet = true;
+ outSet.get(nodeToProcess).dataSet.get(0).value = setSet.get(nodeToProcess).dataSet.get(0).value;
+ outSet.get(nodeToProcess).dataSet.get(1).appSet = true;
+ outSet.get(nodeToProcess).dataSet.get(1).value = setSet.get(nodeToProcess).dataSet.get(1).value;
+ } else if (setSet.get(nodeToProcess).dataSet.get(0).appSet == true) { //App1 is a writer
+ outSet.get(nodeToProcess).dataSet.get(0).appSet = true;
+ outSet.get(nodeToProcess).dataSet.get(0).value = setSet.get(nodeToProcess).dataSet.get(0).value;
+ outSet.get(nodeToProcess).dataSet.get(1).appSet = inSet.get(nodeToProcess).dataSet.get(1).appSet;
+ outSet.get(nodeToProcess).dataSet.get(1).value = inSet.get(nodeToProcess).dataSet.get(1).value;
+ } else if (setSet.get(nodeToProcess).dataSet.get(1).appSet == true) { //App2 is a writer
+ outSet.get(nodeToProcess).dataSet.get(0).appSet = inSet.get(nodeToProcess).dataSet.get(0).appSet;
+ outSet.get(nodeToProcess).dataSet.get(0).value = inSet.get(nodeToProcess).dataSet.get(0).value;
+ outSet.get(nodeToProcess).dataSet.get(1).appSet = true;
+ outSet.get(nodeToProcess).dataSet.get(1).value = setSet.get(nodeToProcess).dataSet.get(1).value;
+ }
+ } else {
+ outSet.get(nodeToProcess).dataSet.get(0).appSet = inSet.get(nodeToProcess).dataSet.get(0).appSet;
+ outSet.get(nodeToProcess).dataSet.get(0).value = inSet.get(nodeToProcess).dataSet.get(0).value;
+ outSet.get(nodeToProcess).dataSet.get(1).appSet = inSet.get(nodeToProcess).dataSet.get(1).appSet;
+ outSet.get(nodeToProcess).dataSet.get(1).value = inSet.get(nodeToProcess).dataSet.get(1).value;
+ }
+
+ //Checking if the output set has changed or not(Add its successors to the change list!)
+ if ((outSet.get(nodeToProcess).dataSet.get(0).appSet != currentDataSet.dataSet.get(0).appSet)||
+ !(outSet.get(nodeToProcess).dataSet.get(0).value.equals(currentDataSet.dataSet.get(0).value))||
+ (outSet.get(nodeToProcess).dataSet.get(1).appSet != currentDataSet.dataSet.get(1).appSet)||
+ !(outSet.get(nodeToProcess).dataSet.get(1).value.equals(currentDataSet.dataSet.get(1).value))) {
+ for (Integer i : succSet.get(nodeToProcess))
+ if (!changed.contains(i))
+ changed.add(i);
+ }
+
+ }
+ }
+
+ //Update the pred
+ if (succSet.containsKey(id)) {
+ ArrayList<Integer> ids = succSet.get(id);
+ if (!ids.contains(parentId)) {
+ ids.add(parentId);
+ succSet.put(id, ids);
+ }
+ } else if (parentId != -2) {
+ ArrayList<Integer> ids = new ArrayList<Integer>();
+ ids.add(parentId);
+ succSet.put(id, ids);
+ }
+
+ //Update the suc
+ if (succSet.containsKey(parentId)) {
+ ArrayList<Integer> ids = succSet.get(parentId);
+ if (!ids.contains(id)) {
+ ids.add(id);
+ succSet.put(parentId, ids);
+ }
+ } else if (parentId != -2) {
+ ArrayList<Integer> ids = new ArrayList<Integer>();
+ ids.add(id);
+ succSet.put(parentId, ids);
+ }
+
+ parentId = id;
+
+ }
+
+ @Override
+ public void stateBacktracked(Search search) {
+ id = search.getStateId();
+ depth = search.getDepth();
+ operation = "backtrack";
+ detail = null;
+
+ out.println("The state is backtracked to state with id: "+id+", depth: "+depth);
+
+ parentId = id;
+ }
+
+ @Override
+ public void searchFinished(Search search) {
+ out.println("----------------------------------- search finished");
+ }
+
+ private String getValue(ThreadInfo ti, Instruction inst, byte type) {
+ StackFrame frame;
+ int lo, hi;
+
+ frame = ti.getTopFrame();
+
+ if ((inst instanceof JVMLocalVariableInstruction) ||
+ (inst instanceof JVMFieldInstruction))
+ {
+ if (frame.getTopPos() < 0)
+ return(null);
+
+ lo = frame.peek();
+ hi = frame.getTopPos() >= 1 ? frame.peek(1) : 0;
+
+ return(decodeValue(type, lo, hi));
+ }
+
+ if (inst instanceof JVMArrayElementInstruction)
+ return(getArrayValue(ti, type));
+
+ return(null);
+ }
+
+ private final static String decodeValue(byte type, int lo, int hi) {
+ switch (type) {
+ case Types.T_ARRAY: return(null);
+ case Types.T_VOID: return(null);
+
+ case Types.T_BOOLEAN: return(String.valueOf(Types.intToBoolean(lo)));
+ case Types.T_BYTE: return(String.valueOf(lo));
+ case Types.T_CHAR: return(String.valueOf((char) lo));
+ case Types.T_DOUBLE: return(String.valueOf(Types.intsToDouble(lo, hi)));
+ case Types.T_FLOAT: return(String.valueOf(Types.intToFloat(lo)));
+ case Types.T_INT: return(String.valueOf(lo));
+ case Types.T_LONG: return(String.valueOf(Types.intsToLong(lo, hi)));
+ case Types.T_SHORT: return(String.valueOf(lo));
+
+ case Types.T_REFERENCE:
+ ElementInfo ei = VM.getVM().getHeap().get(lo);
+ if (ei == null)
+ return(null);
+
+ ClassInfo ci = ei.getClassInfo();
+ if (ci == null)
+ return(null);
+
+ if (ci.getName().equals("java.lang.String"))
+ return('"' + ei.asString() + '"');
+
+ return(ei.toString());
+
+ default:
+ System.err.println("Unknown type: " + type);
+ return(null);
+ }
+ }
+
+ private String getArrayValue(ThreadInfo ti, byte type) {
+ StackFrame frame;
+ int lo, hi;
+
+ frame = ti.getTopFrame();
+ lo = frame.peek();
+ hi = frame.getTopPos() >= 1 ? frame.peek(1) : 0;
+
+ return(decodeValue(type, lo, hi));
+ }
+
+ private byte getType(ThreadInfo ti, Instruction inst) {
+ StackFrame frame;
+ FieldInfo fi;
+ String type;
+
+ frame = ti.getTopFrame();
+ if ((frame.getTopPos() >= 0) && (frame.isOperandRef())) {
+ return (Types.T_REFERENCE);
+ }
+
+ type = null;
+
+ if (inst instanceof JVMLocalVariableInstruction) {
+ type = ((JVMLocalVariableInstruction) inst).getLocalVariableType();
+ } else if (inst instanceof JVMFieldInstruction){
+ fi = ((JVMFieldInstruction) inst).getFieldInfo();
+ type = fi.getType();
+ }
+
+ if (inst instanceof JVMArrayElementInstruction) {
+ return (getTypeFromInstruction(inst));
+ }
+
+ if (type == null) {
+ return (Types.T_VOID);
+ }
+
+ return (decodeType(type));
+ }
+
+ private final static byte getTypeFromInstruction(Instruction inst) {
+ if (inst instanceof JVMArrayElementInstruction)
+ return(getTypeFromInstruction((JVMArrayElementInstruction) inst));
+
+ return(Types.T_VOID);
+ }
+
+ private final static byte decodeType(String type) {
+ if (type.charAt(0) == '?'){
+ return(Types.T_REFERENCE);
+ } else {
+ return Types.getBuiltinType(type);
+ }
+ }
+
+ // Find the variable writer
+ // It should be one of the apps listed in the .jpf file
+ private String getWriter(List<StackFrame> sfList) {
+ // Start looking from the top of the stack backward
+ for(int i=sfList.size()-1; i>=0; i--) {
+ MethodInfo mi = sfList.get(i).getMethodInfo();
+ if(!mi.isJPFInternal()) {
+ String method = mi.getStackTraceName();
+ // Check against the apps in the appSet
+ for(String app : appSet) {
+ // There is only one writer at a time but we need to always
+ // check all the potential writers in the list
+ if (method.contains(app)) {
+ return app;
+ }
+ }
+ }
+ }
+
+ return null;
+ }
+
+ @Override
+ public void instructionExecuted(VM vm, ThreadInfo ti, Instruction nextInsn, Instruction executedInsn) {
+ if (conflictFound == 1) {
+ StringBuilder sb = new StringBuilder();
+ sb.append("Conflict found between two apps!");
+ 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
+ byte type = getType(ti, executedInsn);
+ String value = getValue(ti, executedInsn, type);
+ String writer = getWriter(ti.getStack());
+ // Just return if the writer is not one of the listed apps in the .jpf file
+ if (writer == null)
+ return;
+
+ //Update the HashMap for Set set.
+ if (setSet.containsKey(id)) {
+ if (writer.equals("App1")) {
+ setSet.get(id).dataSet.get(0).appSet = true;
+ setSet.get(id).dataSet.get(0).value = value;
+ } else if (writer.equals("App2")) {
+ setSet.get(id).dataSet.get(1).appSet = true;
+ setSet.get(id).dataSet.get(1).value = value;
+ }
+ } else {
+ HashMap<Integer, DataList> dataSet = new HashMap<Integer, DataList>();
+ DataList dataList1 = new DataList(false, "NA");
+ DataList dataList2 = new DataList(false, "NA");
+ if (writer.equals("App1")) {
+ dataList1.appSet = true;
+ dataList1.value = value;
+ } else if (writer.equals("App2")) {
+ dataList2.appSet = true;
+ dataList2.value = value;
+ }
+ dataSet.put(0, dataList1);
+ dataSet.put(1, dataList2);
+ DataSet tempDataSet = new DataSet(dataSet);
+ setSet.put(id, tempDataSet);
+ }
+
+ }
+ }
+
+
+ }
+
+ }
+
+}