/**
* Look for a path in graph, from def to use. This path has to lie inside an extended basic block
* (and this property implies uniqueness.). The path returned includes from and to.
*
* @param from start point for the path.
* @param to end point for the path.
* @return null if there is no such path.
*/
public List getExtendedBasicBlockPathBetween(Unit from, Unit to) {
UnitGraph g = this;
// if this holds, we're doomed to failure!!!
if (g.getPredsOf(to).size() > 1) return null;
// pathStack := list of succs lists
// pathStackIndex := last visited index in pathStack
LinkedList pathStack = new LinkedList();
LinkedList pathStackIndex = new LinkedList();
pathStack.add(from);
pathStackIndex.add(new Integer(0));
int psiMax = (g.getSuccsOf((Unit) pathStack.get(0))).size();
int level = 0;
while (((Integer) pathStackIndex.get(0)).intValue() != psiMax) {
int p = ((Integer) (pathStackIndex.get(level))).intValue();
List succs = g.getSuccsOf((Unit) (pathStack.get(level)));
if (p >= succs.size()) {
// no more succs - backtrack to previous level.
pathStack.remove(level);
pathStackIndex.remove(level);
level--;
int q = ((Integer) pathStackIndex.get(level)).intValue();
pathStackIndex.set(level, new Integer(q + 1));
continue;
}
Unit betweenUnit = (Unit) (succs.get(p));
// we win!
if (betweenUnit == to) {
pathStack.add(to);
return pathStack;
}
// check preds of betweenUnit to see if we should visit its kids.
if (g.getPredsOf(betweenUnit).size() > 1) {
pathStackIndex.set(level, new Integer(p + 1));
continue;
}
// visit kids of betweenUnit.
level++;
pathStackIndex.add(new Integer(0));
pathStack.add(betweenUnit);
}
return null;
}
/**
* given a DelayabilityAnalysis and the computations of each unit, calculates the latest
* computation-point for each expression.<br>
* the <code>equivRhsMap</code> could be calculated on the fly, but it is <b>very</b> likely that
* it already exists (as similar maps are used for calculating Earliestness, Delayed,...<br>
* the shared set allows more efficient set-operations, when they the computation is merged with
* other analyses/computations.
*
* @param dg a ExceptionalUnitGraph
* @param delayed the delayability-analysis of the same graph.
* @param equivRhsMap all computations of the graph
* @param set the shared flowSet
*/
public LatestComputation(
UnitGraph unitGraph, DelayabilityAnalysis delayed, Map equivRhsMap, BoundedFlowSet set) {
unitToLatest = new HashMap<Unit, FlowSet>(unitGraph.size() + 1, 0.7f);
Iterator unitIt = unitGraph.iterator();
while (unitIt.hasNext()) {
/* create a new Earliest-list for each unit */
Unit currentUnit = (Unit) unitIt.next();
/* basically the latest-set is:
* (delayed) INTERSECT (comp UNION (UNION_successors ~Delayed)) =
* (delayed) MINUS ((INTERSECTION_successors Delayed) MINUS comp).
*/
FlowSet delaySet = (FlowSet) delayed.getFlowBefore(currentUnit);
/* Calculate (INTERSECTION_successors Delayed) */
FlowSet succCompSet = (FlowSet) set.topSet();
List succList = unitGraph.getSuccsOf(currentUnit);
Iterator succIt = succList.iterator();
while (succIt.hasNext()) {
Unit successor = (Unit) succIt.next();
succCompSet.intersection((FlowSet) delayed.getFlowBefore(successor), succCompSet);
}
/* remove the computation of this set: succCompSet is then:
* ((INTERSECTION_successors Delayed) MINUS comp) */
if (equivRhsMap.get(currentUnit) != null) succCompSet.remove(equivRhsMap.get(currentUnit));
/* make the difference: */
FlowSet latest = (FlowSet) delaySet.emptySet();
delaySet.difference(succCompSet, latest);
unitToLatest.put(currentUnit, latest);
}
}
private void buildSuccessor(Chain pegChain) {
// Add regular successors
{
HashMap unitToPeg = (HashMap) unitToPegMap.get(pegChain);
Iterator pegIt = pegChain.iterator();
JPegStmt currentNode, nextNode;
currentNode = pegIt.hasNext() ? (JPegStmt) pegIt.next() : null;
// June 19 add for begin node
if (currentNode != null) {
// System.out.println("currentNode: "+currentNode);
// if the unit is "begin" node
nextNode = pegIt.hasNext() ? (JPegStmt) pegIt.next() : null;
if (currentNode.getName().equals("begin")) {
List<JPegStmt> successors = new ArrayList<JPegStmt>();
successors.add(nextNode);
unitToSuccs.put(currentNode, successors);
currentNode = nextNode;
}
// end June 19 add for begin node
while (currentNode != null) {
// System.out.println("currentNode: "+currentNode);
/* If unitToSuccs contains currentNode, it is the point to inline methods,
* we need not compute its successors again
*/
if (unitToSuccs.containsKey(currentNode) && !currentNode.getName().equals("wait")) {
currentNode = pegIt.hasNext() ? (JPegStmt) pegIt.next() : null;
continue;
}
List<JPegStmt> successors = new ArrayList<JPegStmt>();
Unit unit = currentNode.getUnit();
UnitGraph unitGraph = currentNode.getUnitGraph();
List unitSucc = unitGraph.getSuccsOf(unit);
Iterator succIt = unitSucc.iterator();
while (succIt.hasNext()) {
Unit un = (Unit) succIt.next();
// Don't build the edge from "monitor exit" to exception handler
if (unit instanceof ExitMonitorStmt && exceHandlers.contains(un)) {
// System.out.println("====find it! unit: "+unit+"\n un: "+un);
continue;
} else if (unitToPeg.containsKey(un)) {
JPegStmt pp = (JPegStmt) (unitToPeg.get(un));
if (pp != null && !successors.contains(pp)) successors.add(pp);
}
} // end while
if (currentNode.getName().equals("wait")) {
while (!(currentNode.getName().equals("notified-entry"))) {
currentNode = pegIt.hasNext() ? (JPegStmt) pegIt.next() : null;
}
unitToSuccs.put(currentNode, successors);
// System.out.println("put key: "+currentNode+" into unitToSucc");
} else {
unitToSuccs.put(currentNode, successors);
}
if (currentNode.getName().equals("start")) {
// System.out.println("-----build succ for start----");
if (startToThread.containsKey(currentNode)) {
List runMethodChainList = startToThread.get(currentNode);
Iterator possibleMethodIt = runMethodChainList.iterator();
while (possibleMethodIt.hasNext()) {
Chain subChain = (Chain) possibleMethodIt.next();
if (subChain != null) {
// System.out.println("build succ for subChain");
// buildSuccessor(subGraph, subChain, addExceptionEdges);
buildSuccessor(subChain);
} else System.out.println("*********subgraph is null!!!");
}
}
}
currentNode = pegIt.hasNext() ? (JPegStmt) pegIt.next() : null;
} // while
// June 19 add for begin node
}
// end June 19 add for begin node
}
}