/*
* Copyright (c) 2001, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
package sun.jvm.hotspot.utilities;
import java.io.*;
import java.util.*;
import sun.jvm.hotspot.oops.*;
/** Describes a path from an object back to the root which is keeping
it alive. Elements of the path are (object, field) pairs, where
the object is expressed as a @link{sun.jvm.hotspot.oops.Oop}, and
where the field is expressed as a
@link{sun.jvm.hotspot.oops.FieldIdentifier}. If the element
reflects a root, the Oop will be null. If the element is the end
of the path, the FieldIdentifier will be null. */
public class LivenessPath {
LivenessPath() {
stack = new Stack();
}
/** Number of elements in the path */
public int size() {
return stack.size();
}
/** Fetch the element at the given index; 0-based */
public LivenessPathElement get(int index) throws ArrayIndexOutOfBoundsException {
return (LivenessPathElement) stack.get(index);
}
public void printOn(PrintStream tty) {
for (int j = 0; j < size(); j++) {
LivenessPathElement el = get(j);
tty.print(" - ");
if (el.getObj() != null) {
Oop.printOopValueOn(el.getObj(), tty);
}
if (el.getField() != null) {
if (el.getObj() != null) {
tty.print(", field ");
}
tty.print(el.getField().getName());
}
tty.println();
}
}
/** Indicates whether this path is "complete", i.e., whether the
last element is a root. Convenience routine for LivenessAnalysis. */
boolean isComplete() {
if (size() == 0)
return false;
return peek().isRoot();
}
// Convenience routine for LivenessAnalysis
LivenessPathElement peek() {
return (LivenessPathElement) stack.peek();
}
// Convenience routine for LivenessAnalysis
void push(LivenessPathElement el) {
stack.push(el);
}
// Convenience routine for LivenessAnalysis
void pop() {
stack.pop();
}
// Make a copy of the contents of the path -- the
/**代码未完, 请加载全部代码(NowJava.com).**/