[7u-dev] Request for approval for JDK-7175464 (original) (raw)

[7u-dev] Request for approval for JDK-7175464 - entrySetView field is never updated in NavigableSubMap

Martin Buchholz martinrb at google.com
Sun Feb 10 07:49:39 UTC 2013

[adding lambda-dev]

Here's another refinement to the test case, which shows that a serial clone of Collections.reverseOrder in lambda8 creates a new instance of a new class with the opposite order (which I can't explain):

When run against latest lambda-b76, it gives this output:

x=java.util.Collections$ReverseComparator at 3710b205 y=java.util.Collections$ReverseComparator2 at e9b8b810 x: 1 -1 y: -1 1

import java.util.; import java.io.;

public class ReverseOrder { public static void main(String[] args) throws Throwable { Comparator x = Collections.reverseOrder(); Comparator y = serialClone(x); System.out.printf("x=%s%n", x); System.out.printf("y=%s%n", y); System.out.printf("x: %d %d%n", x.compare(0,1), x.compare(1,0)); System.out.printf("y: %d %d%n", y.compare(0,1), y.compare(1,0)); }

static byte[] serialBytes(Object o) {
    try {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(bos);
        oos.writeObject(o);
        oos.flush();
        oos.close();
        return bos.toByteArray();
    } catch (Throwable t) {
        throw new Error(t);
    }
}

@SuppressWarnings("unchecked")
static <T> T serialClone(T o) {
    try {
        ObjectInputStream ois = new ObjectInputStream
            (new ByteArrayInputStream(serialBytes(o)));
        T clone = (T) ois.readObject();
        return clone;
    } catch (Throwable t) {
        throw new Error(t);
    }
}

}

On Sat, Feb 9, 2013 at 3:31 PM, Martin Buchholz <martinrb at google.com> wrote:

On Sat, Feb 9, 2013 at 3:09 PM, Martin Buchholz <martinrb at google.com>wrote: It looks to me like Collections.reverseOrder no longer deserializes to the same object. It also looks like the definition for that in Collections.java hasn't changed recently. So I suspect that there has been some serious incompatible change to deserialization itself. (It's another matter whether that could break TreeSet). (I have long lobbied for more cross-jdk testing focused on seriallization)

The program below demonstrates the different behavior between jdk7 and jdk8:

Oops - correction - this is not a difference between jdk7 and jdk8, but between jdk8 and lambda8, More specifically, lambda-8-b74 fails, while jdk8-b74 succeeds. Have lambdadukes messed with serialization? import java.util.*; import java.io.*; public class ReverseOrder { public static void main(String[] args) throws Throwable { Comparator c = Collections.reverseOrder(); if (c != serialClone(c)) throw new Error(String.format("c=%s clone=%s", c, serialClone(c))); } static byte[] serialBytes(Object o) { try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bos); oos.writeObject(o); oos.flush(); oos.close(); return bos.toByteArray(); } catch (Throwable t) { throw new Error(t); } } @SuppressWarnings("unchecked") static T serialClone(T o) { try { ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream(serialBytes(o))); T clone = (T) ois.readObject(); return clone; } catch (Throwable t) { throw new Error(t); } } }

On Fri, Feb 8, 2013 at 3:16 PM, Mike Duigou <mike.duigou at oracle.com>wrote: Thank you for catching this Doug. I missed your original post on this topic during my Christmas vacation. ( http://mail.openjdk.java.net/pipermail/core-libs-dev/2012-December/013127.htmlfor those following along at home) I will definitely hold off and follow up on the potentially bad patch to Java 8. I have created an issue to resolve the test breakage, JDK-8007889 Mike On Feb 8 2013, at 11:43 , Doug Lea wrote: > On 02/08/13 14:33, Mike Duigou wrote: >> Hello all; >> >> I would like to backport this change from Java 8. It has been baking in JDK8 for about two months with no problems. >> > > I think it may have problems. > As I mentioned in a post a few months ago, it seems > to be responsible for breakage in a TCK/JCK test; > One derived from a jsr166 tck test at > http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck/TreeSubSetTest.java?view=log > > You need the file for context, but it looks like: > > public void testDescendingSerialization() throws Exception { > NavigableSet x = dset5(); > NavigableSet y = serialClone(x); > > assertTrue(x != y); > assertEquals(x.size(), y.size()); > assertEquals(x.toString(), y.toString()); > assertEquals(x, y); > assertEquals(y, x); > while (!x.isEmpty()) { > assertFalse(y.isEmpty()); > assertEquals(x.pollFirst(), y.pollFirst()); > } > assertTrue(y.isEmpty()); > } > > >> http://bugs.sun.com/bugdatabase/viewbug.do?bugid=7175464 >> >> http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/bf6ceb6b8f80 >> >> The change was previously reviewed by Alan Bateman, Paul Sandoz and David Holmes before going in to Java 8. >> >> Mike >> >

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