/*
* Copyright (c) 2007, 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.
*/
/*
* @test
* @bug 6359979
* @summary Compare List implementations for identical behavior
* @author Martin Buchholz
* @key randomness
*/
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.Random;
import java.util.Vector;
@SuppressWarnings("unchecked")
public class LockStep {
final int DEFAULT_SIZE = 5;
int size; // Running time is O(size**2)
int intArg(String[] args, int i, int defaultValue) {
return args.length > i ? Integer.parseInt(args[i]) : defaultValue;
}
boolean maybe(int n) { return rnd.nextInt(n) == 0; }
void test(String[] args) {
size = intArg(args, 0, DEFAULT_SIZE);
lockSteps(new ArrayList(),
new LinkedList(),
new Vector());
}
void equalLists(List... lists) {
for (List list : lists)
equalLists(list, lists[0]);
}
void equalLists(List x, List y) {
equal(x, y);
equal(y, x);
equal(x.size(), y.size());
equal(x.isEmpty(), y.isEmpty());
equal(x.hashCode(), y.hashCode());
equal(x.toString(), y.toString());
equal(x.toArray(), y.toArray());
}
void lockSteps(List... lists) {
for (int i = 0; i < lists.length; i++)
if (maybe(4)) lists[i] = serialClone(lists[i]);
for (final List list : lists)
testEmptyList(list);
for (int i = 0; i < size; i++) {
ListFrobber adder = randomAdder();
for (final List list : lists) {
adder.frob(list);
equal(list.size(), i+1);
}
equalLists(lists);
}
{
final ListFrobber adder = randomAdder();
final ListFrobber remover = randomRemover();
for (final List list : lists) {
THROWS(ConcurrentModificationException.class,
new F(){void f(){
Iterator it = list.iterator();
adder.frob(list);
it.next();}},
new F(){void f(){
Iterator it = asSubList(list).iterator();
remover.frob(list);
it.next();}},
new F(){void f(){
Iterator it = asSubList(asSubList(list)).iterator();
adder.frob(list);
it.next();}},
new F(){void f(){
List subList = asSubList(list);
remover.frob(list);
subList.get(0);}},
new F(){void f(){
List sl = asSubList(list);
List ssl = asSubList(sl);
adder.frob(sl);
ssl.get(0);}},
new F(){void f(){
List sl = asSubList(list);
List ssl = asSubList(sl);
remover.frob(sl);
ssl.get(0);}});
}
}
for (final List l : lists) {
final List sl = asSubList(l);
final List ssl = asSubList(sl);
ssl.add(0, 42);
equal(ssl.get(0), 42);
equal(sl.get(0), 42);
equal(l.get(0), 42);
final int s = l.size();
final int rndIndex = rnd.nextInt(l.size());
THROWS(IndexOutOfBoundsException.class,
new F(){void f(){l.subList(rndIndex, rndIndex).get(0);}},
new F(){void f(){l.subList(s/2, s).get(s/2 + 1);}},
new F(){void f(){l.subList(s/2, s).get(-1);}}
);
THROWS(IllegalArgumentException.class,
new F(){void f(){ l.subList(1, 0);}},
new F(){void f(){ sl.subList(1, 0);}},
new F(){void f(){ssl.subList(1, 0);}});
}
equalLists(lists);
for (final List list : lists) {
equalLists(list, asSubList(list));
equalLists(list, asSubList(asSubList(list)));
}
for (final List list : lists)
System.out.println(list);
for (int i = lists[0].size(); i > 0; i--) {
ListFrobber remover = randomRemover();
for (final List list : lists)
remover.frob(list);
equalLists(lists);
}
}
<T> List<T> asSubList(List<T> list) {
return list.subList(0, list.size());
}
void testEmptyCollection(Collection<?> c) {
check(c.isEmpty());
equal(c.size(), 0);
equal(c.toString(),"[]");
equal(c.toArray().length, 0);
equal(c.toArray(new Object[0]).length, 0);
Object[] a = new Object[1]; a[0] = Boolean.TRUE;
equal(c.toArray(a), a);
equal(a[0], null);
}
void testEmptyList(List list) {
testEmptyCollection(list);
equal(list.hashCode(), 1);
equal(list, Collections.emptyList());
}
final Random rnd = new Random();
abstract class ListFrobber { abstract void frob(List l); }
ListFrobber randomAdder() {
final Integer e = rnd.nextInt(1024);
final int subListCount = rnd.nextInt(3);
final boolean atBeginning = rnd.nextBoolean();
final boolean useIterator = rnd.nextBoolean();
final boolean simpleIterator = rnd.nextBoolean();
return new ListFrobber() {void frob(List l) {
final int s = l.size();
List ll = l;
for (int i = 0; i < subListCount; i++)
ll = asSubList(ll);
if (! useIterator) {
if (atBeginning) {
switch (rnd.nextInt(3)) {
case 0: ll.add(0, e); break;
case 1: ll.subList(0, rnd.nextInt(s+1)).add(0, e); break;
case 2: ll.subList(0, rnd.nextInt(s+1)).subList(0,0).add(0,e); break;
default: throw new Error();
}
} else {
switch (rnd.nextInt(3)) {
case 0: check(ll.add(e)); break;
case 1: ll.subList(s/2, s).add(s - s/2, e); break;
case 2: ll.subList(s, s).subList(0, 0).add(0, e); break;
default: throw new Error();
}
}
} else {
if (atBeginning) {
ListIterator it = ll.listIterator();
equal(it.nextIndex(), 0);
check(! it.hasPrevious());
it.add(e);
equal(it.previousIndex(), 0);
equal(it.nextIndex(), 1);
check(it.hasPrevious());
} else {
final int siz = ll.size();
ListIterator it = ll.listIterator(siz);
equal(it.previousIndex(), siz-1);
check(! it.hasNext());
it.add(e);
equal(it.previousIndex(), siz);
equal(it.nextIndex(), siz+1);
check(! it.hasNext());
check(it.hasPrevious());
}
}}};
}
ListFrobber randomRemover() {
final int position = rnd.nextInt(3);
final int subListCount = rnd.nextInt(3);
return new ListFrobber() {void frob(List l) {
final int s = l.size();
List ll = l;
for (int i = 0; i < subListCount; i++)
ll = asSubList(ll);
switch (position) {
case 0: // beginning
switch (rnd.nextInt(3)) {
case 0: ll.remove(0); break;
case 1: {
final Iterator it = ll.iterator();
check(it.hasNext());
THROWS(IllegalStateException.class,
new F(){void f(){it.remove();}});
it.next();
it.remove();
THROWS(IllegalStateException.class,
new F(){void f(){it.remove();}});
break;}
case 2: {
final ListIterator it = ll.listIterator();
check(it.hasNext());
THROWS(IllegalStateException.class,
new F(){void f(){it.remove();}});
it.next();
it.remove();
THROWS(IllegalStateException.class,
new F(){void f(){it.remove();}});
break;}
default: throw new Error();
}
break;
case 1: // midpoint
switch (rnd.nextInt(3)) {
case 0: ll.remove(s/2); break;
case 1: {
final ListIterator it = ll.listIterator(s/2);
it.next();
it.remove();
break;
}
case 2: {
final ListIterator it = ll.listIterator(s/2+1);
it.previous();
it.remove();
break;
}
default: throw new Error();
}
break;
case 2: // end
switch (rnd.nextInt(3)) {
case 0: ll.remove(s-1); break;
case 1: ll.subList(s-1, s).clear(); break;
case 2:
final ListIterator it = ll.listIterator(s);
check(! it.hasNext());
check(it.hasPrevious());
THROWS(IllegalStateException.class,
new F(){void f(){it.remove();}});
it.previous();
equal(it.nextIndex(), s-1);
check(it.hasNext());
it.remove();
equal(it.nextIndex(), s-1);
check(! it.hasNext());
THROWS(IllegalStateException.class,
new F(){void f(){it.remove();}});
break;
default: throw new Error();
}
break;
default: throw new Error();
}}};
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
<T> void equal(T[] x, T[] y) {check(Arrays.equals(x,y));}
public static void main(String[] args) throws Throwable {
new LockStep().instanceMain(args);}
void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
abstract class F {abstract void f() throws Throwable;}
void THROWS(Class<? extends Throwable> k, F... fs) {
for (F f : fs)
try {f.f(); fail("Expected " + k.getName() + " not thrown");}
catch (Throwable t) {
if (k.isAssignableFrom(t.getClass())) pass();
else unexpected(t);}}
static byte[] serializedForm(Object obj) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
new ObjectOutputStream(baos).writeObject(obj);
return baos.toByteArray();
} catch (IOException e) { throw new RuntimeException(e); }}
static Object readObject(byte[] bytes)
throws IOException, ClassNotFoundException {
InputStream is = new ByteArrayInputStream(bytes);
return new ObjectInputStream(is).readObject();}
@SuppressWarnings("unchecked")
static <T> T serialClone(T obj) {
try { return (T) readObject(serializedForm(obj)); }
catch (Exception e) { throw new RuntimeException(e); }}
}