HashSet<Node> changed = new HashSet<Node>(currentNode.getSuccessors());
while(!changed.isEmpty()) {
- // Get the first element of HashSet and remove it from the changed set
- Node nodeToProcess = changed.iterator().next();
- changed.remove(nodeToProcess);
-
- // Update the sets, store the outSet to temp before its changes
- boolean isChanged = updateSets(nodeToProcess);
-
- // Check for a conflict
- if (checkForConflict(nodeToProcess))
- return true;
-
- // Checking if the out set has changed or not(Add its successors to the change list!)
- if (isChanged) {
- for (Node i : nodeToProcess.getSuccessors()) {
- if (!changed.contains(i))
- changed.add(i);
- }
+ // Get the first element of HashSet and remove it from the changed set
+ Node nodeToProcess = changed.iterator().next();
+ changed.remove(nodeToProcess);
+
+ // Update the edge
+ boolean isChanged = updateEdge(currentNode, nodeToProcess);
+
+ // Check for a conflict in this transition(currentNode -> nodeToProcess)
+ if (checkForConflict(currentNode))
+ return true;
+
+ // Checking if the out set has changed or not(Add its successors to the change list!)
+ if (isChanged) {
+ for (Node i : nodeToProcess.getSuccessors()) {
+ if (!changed.contains(i))
+ changed.add(i);
+ }
+ }
}
- }
-
- return false;
- }
-
- boolean setOutSet(Node currentNode) {
- Integer prevSize = currentNode.getOutSet().size();
-
- // Update based on setSet
- for (NameValuePair i : currentNode.getSetSet()) {
- if (currentNode.getOutSet().contains(i))
- currentNode.getOutSet().remove(i);
- currentNode.getOutSet().add(i);
- }
- // Add all the inSet
- currentNode.getOutSet().addAll(currentNode.getInSet());
-
- // Check if the outSet is changed
- if (!prevSize.equals(currentNode.getOutSet().size()))
- return true;
-
- return false;
+ return false;
}
- void setInSet(Node currentNode) {
- for (Node i : currentNode.getPredecessors()) {
- currentNode.getInSet().addAll(i.getOutSet());
- }
+ String createErrorMessage(NameValuePair pair, HashMap<String, String> valueMap, HashMap<String, Integer> writerMap) {
+ String message = "Conflict found between the two apps. App"+pair.getAppNum()+
+ " has written the value: "+pair.getValue()+
+ " to the variable: "+pair.getVarName()+" while App"+
+ writerMap.get(pair.getVarName())+" is overwriting the value: "
+ +valueMap.get(pair.getVarName())+" to the same variable!";
+ return message;
}
- boolean checkForConflict(Node currentNode) {
+ boolean checkForConflict(Node nodeToProcess) {
HashMap<String, String> valueMap = new HashMap<String, String>(); // HashMap from varName to value
HashMap<String, Integer> writerMap = new HashMap<String, Integer>(); // HashMap from varName to appNum
- for (NameValuePair i : currentNode.getSetSet()) {
- if (i.getIsManual()) // Manual input: we have no conflict
- continue;
-
- valueMap.put(i.getVarName(), i.getValue());
- if (writerMap.containsKey(i.getVarName()))
- writerMap.put(i.getVarName(), i.getAppNum()+writerMap.get(i.getVarName())); // We have two writers?
- else
- writerMap.put(i.getVarName(), i.getAppNum());
+ // Update the valueMap and check if we have conflict in the setSet
+ for (NameValuePair i : nodeToProcess.getSetSet()) {
+ if (i.getIsManual()) // Manual input: we have no conflict
+ continue; // If this manual write is the last write, this is actually a break
+
+ if (valueMap.containsKey(i.getVarName())) {
+ if (!valueMap.get(i.getVarName()).equals(i.getValue())) { // Check if their value is different we have a conflict
+ errorMessage = createErrorMessage(i, valueMap, writerMap);
+ return true;
+ }
+ else // We have two writers writing the same value
+ writerMap.put(i.getVarName(), i.getAppNum()+writerMap.get(i.getVarName()));
+ } else {
+ valueMap.put(i.getVarName(), i.getValue());
+ writerMap.put(i.getVarName(), i.getAppNum());
+ }
}
- // Comparing the inSet and setSet to find the conflict
- for (NameValuePair i : currentNode.getInSet()) {
- if (valueMap.containsKey(i.getVarName())) {
- String value = valueMap.get(i.getVarName());
- Integer writer = writerMap.get(i.getVarName());
- if ((value != null)&&(writer != null)) {
- if (!value.equals(i.getValue())&&!writer.equals(i.getAppNum())) { // We have different values
- errorMessage = "Conflict found between the two apps. App"+i.getAppNum()+" has written the value: "+i.getValue()+
- " to the variable: "+i.getVarName()+" while App"+writerMap.get(i.getVarName())+" is overwriting the value: "
- +valueMap.get(i.getVarName())+" to the same variable!";
- return true;
- }
- }
- }
+ // Comparing the outSet to setSet
+ for (NameValuePair i : nodeToProcess.getOutSet()) {
+ if (valueMap.containsKey(i.getVarName())) {
+ String value = valueMap.get(i.getVarName());
+ Integer writer = writerMap.get(i.getVarName());
+ if ((value != null)&&(writer != null)) {
+ if (!value.equals(i.getValue())&&!writer.equals(i.getAppNum())) { // We have different values
+ errorMessage = createErrorMessage(i, valueMap, writerMap);
+ return true;
+ }
+ }
+ }
}
return false;
}
- boolean updateSets(Node currentNode) {
- // Set input set according to output set of pred states of current state
- setInSet(currentNode);
+ boolean updateEdge(Node parentNode, Node currentNode) {
+ HashSet<NameValuePair> setSet = currentNode.getSetSetMap().get(parentNode);
+ HashSet<String> updatedVarNames = new HashSet<String>();
+ HashMap<String, Integer> lastWriter = new HashMap<String, Integer>(); // Store the last writer of each variable
+ boolean isChanged = false;
- // Set outSet according to inSet, and setSet of current node, check if there is a change
- return setOutSet(currentNode);
+ for (NameValuePair i : setSet) {
+ updatedVarNames.add(i.getVarName());
+ lastWriter.put(i.getVarName(), i.getAppNum());
+ }
+
+ for (NameValuePair i : parentNode.getOutSet()) {
+ if (!updatedVarNames.contains(i.getVarName()))
+ isChanged |= currentNode.getOutSet().add(i);
+ }
+
+ for (NameValuePair i : setSet) {
+ if (i.getAppNum().equals(lastWriter.get(i.getVarName()))) // Add the last writer of each variable to outSet
+ isChanged |= currentNode.getOutSet().add(i);
+ }
+
+ return isChanged;
}
static class Node {
Integer id;
HashSet<Node> predecessors = new HashSet<Node>();
HashSet<Node> successors = new HashSet<Node>();
- HashSet<NameValuePair> inSet = new HashSet<NameValuePair>();
HashSet<NameValuePair> setSet = new HashSet<NameValuePair>();
HashSet<NameValuePair> outSet = new HashSet<NameValuePair>();
+ HashMap<Node, HashSet<NameValuePair>> setSetMap = new HashMap<Node, HashSet<NameValuePair>>();
+
Node(Integer id) {
this.id = id;
}
void setSetSet(HashSet<NameValuePair> setSet, boolean isManual) {
- if (isManual)
- this.setSet = new HashSet<NameValuePair>();
- for (NameValuePair i : setSet) {
- this.setSet.add(new NameValuePair(i.getAppNum(), i.getValue(), i.getVarName(), i.getIsManual()));
- }
+ if (isManual)
+ this.setSet = new HashSet<NameValuePair>();
+ for (NameValuePair i : setSet) {
+ this.setSet.add(new NameValuePair(i.getAppNum(), i.getValue(), i.getVarName(), i.getIsManual()));
+ }
}
Integer getId() {
return successors;
}
- HashSet<NameValuePair> getInSet() {
- return inSet;
- }
-
HashSet<NameValuePair> getSetSet() {
return setSet;
}
HashSet<NameValuePair> getOutSet() {
return outSet;
}
+
+ HashMap<Node, HashSet<NameValuePair>> getSetSetMap() {
+ return setSetMap;
+ }
}
static class NameValuePair {
boolean isManual;
NameValuePair(Integer appNum, String value, String varName, boolean isManual) {
- this.appNum = appNum;
- this.value = value;
- this.varName = varName;
- this.isManual = isManual;
+ this.appNum = appNum;
+ this.value = value;
+ this.varName = varName;
+ this.isManual = isManual;
}
void setAppNum(Integer appNum) {
depth = search.getDepth();
operation = "forward";
+ // Check for the conflict in this new transition
+ conflictFound = checkForConflict(parentNode);
+
// Add the node to the list of nodes
nodes.put(id, new Node(id));
Node currentNode = nodes.get(id);
if (!(parentNode.getSuccessors().contains(currentNode)))
parentNode.addSuccessor(currentNode);
- // Update the sets, check if the outSet is changed or not
- boolean isChanged = updateSets(currentNode);
-
- // Check for a conflict
- conflictFound = checkForConflict(currentNode);
+
+ // Update the setSetMap of the current node
+ for (Node i : currentNode.getPredecessors()) {
+ currentNode.getSetSetMap().put(i, i.getSetSet());
+ }
+
+ // Update the edge and check if the outset of the current node is changed or not to propagate the change
+ boolean isChanged = updateEdge(parentNode, currentNode);
// Check if the outSet of this state has changed, update all of its successors' sets if any
if (isChanged)