2 * Copyright (C) 2014, United States Government, as represented by the
3 * Administrator of the National Aeronautics and Space Administration.
6 * The Java Pathfinder core (jpf-core) platform is licensed under the
7 * Apache License, Version 2.0 (the "License"); you may not use this file except
8 * in compliance with the License. You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0.
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
18 package gov.nasa.jpf.listener;
20 import gov.nasa.jpf.Config;
21 import gov.nasa.jpf.JPF;
22 import gov.nasa.jpf.ListenerAdapter;
23 import gov.nasa.jpf.search.Search;
24 import gov.nasa.jpf.jvm.bytecode.*;
25 import gov.nasa.jpf.vm.*;
26 import gov.nasa.jpf.vm.bytecode.LocalVariableInstruction;
27 import gov.nasa.jpf.vm.bytecode.ReadInstruction;
28 import gov.nasa.jpf.vm.bytecode.StoreInstruction;
29 import gov.nasa.jpf.vm.bytecode.WriteInstruction;
31 import java.io.PrintWriter;
36 * Listener using data flow analysis to find conflicts between smartApps.
39 public class ConflictTracker extends ListenerAdapter {
41 private final PrintWriter out;
42 private final HashSet<String> conflictSet = new HashSet<String>(); // Variables we want to track
43 private final HashSet<String> appSet = new HashSet<String>(); // Apps we want to find their conflicts
44 private final HashSet<String> manualSet = new HashSet<String>(); // Writer classes with manual inputs to detect direct-direct(No Conflict) interactions
45 private final HashMap<Integer, Node> nodes = new HashMap<Integer, Node>(); // Nodes of a graph
46 private ArrayList<NameValuePair> tempSetSet = new ArrayList<NameValuePair>();
48 private long startTime;
49 private Node parentNode = new Node(-2);
50 private String operation;
51 private String detail;
52 private String errorMessage;
55 private boolean conflictFound = false;
56 private boolean manual = false;
58 private final String SET_LOCATION_METHOD = "setLocationMode";
59 private final String LOCATION_VAR = "locationMode";
61 public ConflictTracker(Config config, JPF jpf) {
62 out = new PrintWriter(System.out, true);
64 String[] conflictVars = config.getStringArray("variables");
65 // We are not tracking anything if it is null
66 if (conflictVars != null) {
67 for (String var : conflictVars) {
71 String[] apps = config.getStringArray("apps");
72 // We are not tracking anything if it is null
74 for (String var : apps) {
78 String[] manualClasses = config.getStringArray("manualClasses");
79 // We are not tracking anything if it is null
80 if (manualClasses != null) {
81 for (String var : manualClasses) {
86 // Timeout input from config is in minutes, so we need to convert into millis
87 timeout = config.getInt("timeout", 0) * 60 * 1000;
88 startTime = System.currentTimeMillis();
91 boolean propagateTheChange(Node currentNode) {
92 HashSet<Node> changed = new HashSet<Node>(currentNode.getSuccessors());
94 while(!changed.isEmpty()) {
95 // Get the first element of HashSet and remove it from the changed set
96 Node nodeToProcess = changed.iterator().next();
97 changed.remove(nodeToProcess);
100 boolean isChanged = updateEdge(currentNode, nodeToProcess);
102 // Check for a conflict in this transition(currentNode -> nodeToProcess)
103 if (checkForConflict(currentNode))
106 // Checking if the out set has changed or not(Add its successors to the change list!)
108 for (Node i : nodeToProcess.getSuccessors()) {
109 if (!changed.contains(i))
118 String createErrorMessage(NameValuePair pair, HashMap<String, String> valueMap, HashMap<String, Integer> writerMap) {
119 String message = "Conflict found between the two apps. App"+pair.getAppNum()+
120 " has written the value: "+pair.getValue()+
121 " to the variable: "+pair.getVarName()+" while App"+
122 writerMap.get(pair.getVarName())+" is overwriting the value: "
123 +valueMap.get(pair.getVarName())+" to the same variable!";
127 boolean checkForConflict(Node nodeToProcess) {
128 HashMap<String, String> valueMap = new HashMap<String, String>(); // HashMap from varName to value
129 HashMap<String, Integer> writerMap = new HashMap<String, Integer>(); // HashMap from varName to appNum
131 // Update the valueMap
132 for (int i = 0;i < nodeToProcess.getSetSet().size();i++) {
133 NameValuePair nameValuePair = nodeToProcess.getSetSet().get(i);
135 if (valueMap.containsKey(nameValuePair.getVarName())) {
136 // Check if we have a same writer
137 if (!writerMap.get(nameValuePair.getVarName()).equals(nameValuePair.getAppNum())) {
138 // Check if we have a conflict or not
139 if (!valueMap.get(nameValuePair.getVarName()).equals(nameValuePair.getValue())) {
140 errorMessage = createErrorMessage(nameValuePair, valueMap, writerMap);
142 } else { // We have two writers writing the same value
143 writerMap.put(nameValuePair.getVarName(), 3); // 3 represents both apps
146 // Check if we have more than one value with the same writer
147 if (!valueMap.get(nameValuePair.getVarName()).equals(nameValuePair.getValue())) {
148 valueMap.put(nameValuePair.getVarName(), "twoValue"); // We have one writer writing more than one value in a same event
152 valueMap.put(nameValuePair.getVarName(), nameValuePair.getValue());
153 writerMap.put(nameValuePair.getVarName(), nameValuePair.getAppNum());
157 // Comparing the outSet to setSet
158 for (NameValuePair i : nodeToProcess.getOutSet()) {
159 if (valueMap.containsKey(i.getVarName())) {
160 String value = valueMap.get(i.getVarName());
161 Integer writer = writerMap.get(i.getVarName());
162 if ((value != null)&&(writer != null)) {
163 if (!value.equals(i.getValue())&&!writer.equals(i.getAppNum())) { // We have different values
164 errorMessage = createErrorMessage(i, valueMap, writerMap);
174 boolean updateEdge(Node parentNode, Node currentNode) {
175 ArrayList<NameValuePair> setSet = currentNode.getSetSetMap().get(parentNode);
176 HashSet<String> updatedVarNames = new HashSet<String>();
177 HashMap<String, Integer> lastWriter = new HashMap<String, Integer>(); // Store the last writer of each variable
178 boolean isChanged = false;
180 for (int i = 0;i < setSet.size();i++) {
181 updatedVarNames.add(setSet.get(i).getVarName());
182 lastWriter.put(setSet.get(i).getVarName(), setSet.get(i).getAppNum());
185 for (NameValuePair i : parentNode.getOutSet()) {
186 if (!updatedVarNames.contains(i.getVarName()))
187 isChanged |= currentNode.getOutSet().add(i);
190 for (int i = 0;i < setSet.size();i++) {
191 if (setSet.get(i).getAppNum().equals(lastWriter.get(setSet.get(i).getVarName()))) // Add the last writer of each variable to outSet
192 isChanged |= currentNode.getOutSet().add(setSet.get(i));
200 HashSet<Node> predecessors = new HashSet<Node>();
201 HashSet<Node> successors = new HashSet<Node>();
202 HashSet<NameValuePair> outSet = new HashSet<NameValuePair>();
203 HashMap<Node, ArrayList<NameValuePair>> setSetMap = new HashMap<Node, ArrayList<NameValuePair>>();
204 ArrayList<NameValuePair> setSet = new ArrayList<NameValuePair>();
211 void addPredecessor(Node node) {
212 predecessors.add(node);
215 void addSuccessor(Node node) {
216 successors.add(node);
219 void setSetSet(ArrayList<NameValuePair> setSet, boolean isManual) {
221 this.setSet = new ArrayList<NameValuePair>();
223 for (int i = 0;i < setSet.size();i++) {
224 this.setSet.add(new NameValuePair(setSet.get(i).getAppNum(), setSet.get(i).getValue(),
225 setSet.get(i).getVarName(), setSet.get(i).getIsManual()));
233 HashSet<Node> getPredecessors() {
237 HashSet<Node> getSuccessors() {
241 ArrayList<NameValuePair> getSetSet() {
245 HashSet<NameValuePair> getOutSet() {
249 HashMap<Node, ArrayList<NameValuePair>> getSetSetMap() {
254 static class NameValuePair {
260 NameValuePair(Integer appNum, String value, String varName, boolean isManual) {
261 this.appNum = appNum;
263 this.varName = varName;
264 this.isManual = isManual;
267 void setAppNum(Integer appNum) {
268 this.appNum = appNum;
271 void setValue(String value) {
275 void setVarName(String varName) {
276 this.varName = varName;
279 void setIsManual(String varName) {
280 this.isManual = isManual;
283 Integer getAppNum() {
291 String getVarName() {
295 boolean getIsManual() {
300 public boolean equals(Object o) {
301 if (o instanceof NameValuePair) {
302 NameValuePair other = (NameValuePair) o;
303 if (varName.equals(other.getVarName()))
304 return appNum.equals(other.getAppNum());
310 public int hashCode() {
311 return appNum.hashCode() * 31 + varName.hashCode();
316 public void stateRestored(Search search) {
317 id = search.getStateId();
318 depth = search.getDepth();
319 operation = "restored";
322 out.println("The state is restored to state with id: "+id+", depth: "+depth);
324 // Update the parent node
325 if (nodes.containsKey(id)) {
326 parentNode = nodes.get(id);
328 parentNode = new Node(id);
333 public void searchStarted(Search search) {
334 out.println("----------------------------------- search started");
339 public void stateAdvanced(Search search) {
340 String theEnd = null;
341 id = search.getStateId();
342 depth = search.getDepth();
343 operation = "forward";
345 // Check for the conflict in this new transition
346 conflictFound = checkForConflict(parentNode);
348 // Add the node to the list of nodes
349 nodes.put(id, new Node(id));
350 Node currentNode = nodes.get(id);
352 // Update the setSet for this new node
353 currentNode.setSetSet(tempSetSet, manual);
354 tempSetSet = new ArrayList<NameValuePair>();
357 if (search.isNewState()) {
363 if (search.isEndState()) {
364 out.println("This is the last state!");
368 out.println("The state is forwarded to state with id: "+id+", depth: "+depth+" which is "+detail+" state: "+"% "+theEnd);
370 // Updating the predecessors for this node
371 // Check if parent node is already in successors of the current node or not
372 if (!(currentNode.getPredecessors().contains(parentNode)))
373 currentNode.addPredecessor(parentNode);
375 // Update the successors for this node
376 // Check if current node is already in successors of the parent node or not
377 if (!(parentNode.getSuccessors().contains(currentNode)))
378 parentNode.addSuccessor(currentNode);
381 // Update the setSetMap of the current node
382 for (Node i : currentNode.getPredecessors()) {
383 currentNode.getSetSetMap().put(i, i.getSetSet());
386 // Update the edge and check if the outset of the current node is changed or not to propagate the change
387 boolean isChanged = updateEdge(parentNode, currentNode);
389 // Check if the outSet of this state has changed, update all of its successors' sets if any
391 conflictFound = conflictFound || propagateTheChange(currentNode);
393 // Update the parent node
394 if (nodes.containsKey(id)) {
395 parentNode = nodes.get(id);
397 parentNode = new Node(id);
402 public void stateBacktracked(Search search) {
403 id = search.getStateId();
404 depth = search.getDepth();
405 operation = "backtrack";
408 out.println("The state is backtracked to state with id: "+id+", depth: "+depth);
410 // Update the parent node
411 if (nodes.containsKey(id)) {
412 parentNode = nodes.get(id);
414 parentNode = new Node(id);
419 public void searchFinished(Search search) {
420 out.println("----------------------------------- search finished");
423 private String getValue(ThreadInfo ti, Instruction inst, byte type) {
427 frame = ti.getTopFrame();
429 if ((inst instanceof JVMLocalVariableInstruction) ||
430 (inst instanceof JVMFieldInstruction))
432 if (frame.getTopPos() < 0)
436 hi = frame.getTopPos() >= 1 ? frame.peek(1) : 0;
438 return(decodeValue(type, lo, hi));
441 if (inst instanceof JVMArrayElementInstruction)
442 return(getArrayValue(ti, type));
447 private final static String decodeValue(byte type, int lo, int hi) {
449 case Types.T_ARRAY: return(null);
450 case Types.T_VOID: return(null);
452 case Types.T_BOOLEAN: return(String.valueOf(Types.intToBoolean(lo)));
453 case Types.T_BYTE: return(String.valueOf(lo));
454 case Types.T_CHAR: return(String.valueOf((char) lo));
455 case Types.T_DOUBLE: return(String.valueOf(Types.intsToDouble(lo, hi)));
456 case Types.T_FLOAT: return(String.valueOf(Types.intToFloat(lo)));
457 case Types.T_INT: return(String.valueOf(lo));
458 case Types.T_LONG: return(String.valueOf(Types.intsToLong(lo, hi)));
459 case Types.T_SHORT: return(String.valueOf(lo));
461 case Types.T_REFERENCE:
462 ElementInfo ei = VM.getVM().getHeap().get(lo);
466 ClassInfo ci = ei.getClassInfo();
470 if (ci.getName().equals("java.lang.String"))
471 return('"' + ei.asString() + '"');
473 return(ei.toString());
476 System.err.println("Unknown type: " + type);
481 private String getArrayValue(ThreadInfo ti, byte type) {
485 frame = ti.getTopFrame();
487 hi = frame.getTopPos() >= 1 ? frame.peek(1) : 0;
489 return(decodeValue(type, lo, hi));
492 private byte getType(ThreadInfo ti, Instruction inst) {
497 frame = ti.getTopFrame();
498 if ((frame.getTopPos() >= 0) && (frame.isOperandRef())) {
499 return (Types.T_REFERENCE);
504 if (inst instanceof JVMLocalVariableInstruction) {
505 type = ((JVMLocalVariableInstruction) inst).getLocalVariableType();
506 } else if (inst instanceof JVMFieldInstruction){
507 fi = ((JVMFieldInstruction) inst).getFieldInfo();
511 if (inst instanceof JVMArrayElementInstruction) {
512 return (getTypeFromInstruction(inst));
516 return (Types.T_VOID);
519 return (decodeType(type));
522 private final static byte getTypeFromInstruction(Instruction inst) {
523 if (inst instanceof JVMArrayElementInstruction)
524 return(getTypeFromInstruction((JVMArrayElementInstruction) inst));
526 return(Types.T_VOID);
529 private final static byte decodeType(String type) {
530 if (type.charAt(0) == '?'){
531 return(Types.T_REFERENCE);
533 return Types.getBuiltinType(type);
537 // Find the variable writer
538 // It should be one of the apps listed in the .jpf file
539 private String getWriter(List<StackFrame> sfList, HashSet<String> writerSet) {
540 // Start looking from the top of the stack backward
541 for(int i=sfList.size()-1; i>=0; i--) {
542 MethodInfo mi = sfList.get(i).getMethodInfo();
543 if(!mi.isJPFInternal()) {
544 String method = mi.getStackTraceName();
545 // Check against the writers in the writerSet
546 for(String writer : writerSet) {
547 if (method.contains(writer)) {
557 private void writeWriterAndValue(String writer, String value, String var) {
558 // Update the temporary Set set.
559 NameValuePair temp = new NameValuePair(1, value, var, manual);
560 if (writer.equals("App2"))
561 temp = new NameValuePair(2, value, var, manual);
563 tempSetSet.add(temp);
567 public void instructionExecuted(VM vm, ThreadInfo ti, Instruction nextInsn, Instruction executedInsn) {
568 // Instantiate timeoutTimer
570 if (System.currentTimeMillis() - startTime > timeout) {
571 StringBuilder sbTimeOut = new StringBuilder();
572 sbTimeOut.append("Execution timeout: " + (timeout / (60 * 1000)) + " minutes have passed!");
573 Instruction nextIns = ti.createAndThrowException("java.lang.RuntimeException", sbTimeOut.toString());
574 ti.setNextPC(nextIns);
579 StringBuilder sb = new StringBuilder();
580 sb.append(errorMessage);
581 Instruction nextIns = ti.createAndThrowException("java.lang.RuntimeException", sb.toString());
582 ti.setNextPC(nextIns);
584 if (conflictSet.contains(LOCATION_VAR)) {
585 MethodInfo mi = executedInsn.getMethodInfo();
586 // Find the last load before return and get the value here
587 if (mi.getName().equals(SET_LOCATION_METHOD) &&
588 executedInsn instanceof ALOAD && nextInsn instanceof ARETURN) {
589 byte type = getType(ti, executedInsn);
590 String value = getValue(ti, executedInsn, type);
592 // Extract the writer app name
593 ClassInfo ci = mi.getClassInfo();
594 String writer = ci.getName();
596 // Update the temporary Set set.
597 writeWriterAndValue(writer, value, LOCATION_VAR);
600 if (executedInsn instanceof WriteInstruction) {
601 String varId = ((WriteInstruction) executedInsn).getFieldInfo().getFullName();
602 for (String var : conflictSet) {
603 if (varId.contains(var)) {
605 byte type = getType(ti, executedInsn);
606 String value = getValue(ti, executedInsn, type);
607 String writer = getWriter(ti.getStack(), appSet);
608 // Just return if the writer is not one of the listed apps in the .jpf file
612 if (getWriter(ti.getStack(), manualSet) != null)
615 // Update the temporary Set set.
616 writeWriterAndValue(writer, value, var);