Re: 回复： 回复： what to do next to fix JDK-8230557. thanks
Hi 未来阳光,
As David has pointed out, your proposed fix would break binary and
source compatibility of BitSet.size() method, so it is not acceptable.
BitSet API allows addressing individual bits using non-negative 'int'
typed indexes (analogous to indexes of Java arrays). The range of
indexes is: 0 ... 2^31 - 1 (0 ... Integer.MAX_VALUE). The maximum "size"
of BitSet is therefore 2^31. Unfortunately, this value can't be
"corectly" represented with signed 32 bit integer (int). Only in this
corner case, - 2^31 (Integer.MIN_VALUE) is the interpreted value
returned from size(). If one would interpret it as unsigned 32 bit
integer value, it is entirely correct. For example, this holds:
Integer.toUnsignedLong(new BitSet(Integer.MAX_VALUE).size()) == 1L << 31
It is also always true what javadoc says about size(): "The maximum
element in the set is the size - 1st element"
The following holds also for this corner case:
new BitSet(Integer.MAX_VALUE).size() - 1 == Integer.MAX_VALUE;
So perhaps, the fix could be just to describe this corner case in the
spec. And perhaps, to support the following use case in the corner case:
BitSet set1 = ...
...
BitSet set2 = new BitSet(set1.size());
... by modifying the BitSet constructor to accept the Integer.MIN_VALUE
in addition to all the non-negative values as the 'nbits' parameter.
What do you think?
Regards, Peter
On 9/5/19 8:31 AM, David Holmes wrote:
Hi,
On 5/09/2019 4:11 pm, 未来阳光 wrote:
Thanks very much.
*BUG-LINK:* https://bugs.openjdk.java.net/browse/JDK-8230557
*Describe: *
the return type of the method BitSet#size is int, so the method may
return a negative value in some case, for example, will return
-2147483648.
```
BitSet bitSet = new BitSet(Integer.MAX_VALUE);
for (int i = 0; i < Integer.MAX_VALUE - 1000; i++) {
bitSet.set(i);
}
System.out.println(bitSet.size());
```
EXPECTED: 2147483648, but ACTUAL: -2147483648.
*FIX*
I have put the patch in the attachment of the mail.
In case the attachment got stripped form the mailing list the proposed
fix is:
- public int size() {
- return words.length * BITS_PER_WORD;
+ public long size() {
+ return (long) words.length * BITS_PER_WORD;
Unfortunately this simple fix it not possible. You can't just change
the return type of the method to long as that is a source-incompatible
change and would not be approved [1]. Instead the return value should
be capped at Integer.MAX_VALUE - but I'll leave that for someone from
core-libs team to pick up. Also look at the evaluation in:
https://bugs.openjdk.java.net/browse/JDK-4213570
Cheers,
David
[1] https://wiki.openjdk.java.net/display/csr/CSR+FAQs
-- 原始邮件 --
*发件人:* "David Holmes";
*发送时间:* 2019年9月5日(星期四) 下午2:00
*收件人:* "未来阳光"<2217232...@qq.com>;"core-libs-dev"d...@openjdk.java.net>;
*主题:* Re: 回复： what to do next to fix JDK-8230557. thanks
On 5/09/2019 3:46 pm, 未来阳光 wrote:
>
> hi, developers.
>
> Can someone help me? thanks very much !!
Help you how exactly. As I stated your are up to step 2 of the how to
contribute process. If you have a suggested fix for the bug then put
that in an email as described.
Thanks,
David
>
> -- 原始邮件 --
> *发件人:* "David Holmes";
> *发送时间:* 2019年9月5日(星期四) 中午1:44
> *收件人:* "未来阳光"<2217232...@qq.com>;"core-libs-dev" d...@openjdk.java.net>;
> *主题:* Re: what to do next to fix JDK-8230557. thanks
>
> On 5/09/2019 3:35 pm, 未来阳光 wrote:
> > Hi, leaders.
>
> Hi,
>
> No "leaders" here only developers :)
>
> >
> > A few days ago, I report a bug in core lib[1]. According to the
> contribute document[2], I had send oca to oracle andmy name has
> been listed onoca[3].
>
> Welcome aboard!
>
> > But I still can't push my changes to jdk, can someone tell me
how to
> do next? thanks very match!!
>
> You can't push anything until you become a Committer and before
that you
> have to become an Author. The steps for contributing are outlined
here:
>
> http://openjdk.java.net/contribute/
>
> and you would seem to be up to step 2. :)
>
> Cheers,
> David
>
> >
> >
> >
> >
> > [1]https://bugs.openjdk.java.net/browse/JDK-8230557
> >
> > [2]http://openjdk.java.net/contribute/
> > [3]https://www.oracle.com/technetwork/community/oca-486395.html
> >
> >
> >
> >
> >
> > --原始邮件--
> > 发件人:"Bug Report
> Notification" > 发送时间:2019年9月5日(星期四) 凌晨3:33
> > 收件人:"未来阳光"<2217232...@qq.com;
> >
> > 主题:Update Notification: Bug Report - JDK-8230557
>
Re: 回复： 回复： what to do next to fix JDK-8230557. thanks
Hi,
On 5/09/2019 4:11 pm, 未来阳光 wrote:
Thanks very much.
*BUG-LINK:* https://bugs.openjdk.java.net/browse/JDK-8230557
*Describe: *
the return type of the method BitSet#size is int, so the method may
return a negative value in some case, for example, will return -2147483648.
```
BitSet bitSet = new BitSet(Integer.MAX_VALUE);
for (int i = 0; i < Integer.MAX_VALUE - 1000; i++) {
bitSet.set(i);
}
System.out.println(bitSet.size());
```
EXPECTED: 2147483648, but ACTUAL: -2147483648.
*FIX*
I have put the patch in the attachment of the mail.
In case the attachment got stripped form the mailing list the proposed
fix is:
-public int size() {
-return words.length * BITS_PER_WORD;
+public long size() {
+return (long) words.length * BITS_PER_WORD;
Unfortunately this simple fix it not possible. You can't just change the
return type of the method to long as that is a source-incompatible
change and would not be approved [1]. Instead the return value should be
capped at Integer.MAX_VALUE - but I'll leave that for someone from
core-libs team to pick up. Also look at the evaluation in:
https://bugs.openjdk.java.net/browse/JDK-4213570
Cheers,
David
[1] https://wiki.openjdk.java.net/display/csr/CSR+FAQs
-- 原始邮件 --
*发件人:* "David Holmes";
*发送时间:* 2019年9月5日(星期四) 下午2:00
*收件人:* "未来阳光"<2217232...@qq.com>;"core-libs-dev"d...@openjdk.java.net>;
*主题:* Re: 回复： what to do next to fix JDK-8230557. thanks
On 5/09/2019 3:46 pm, 未来阳光 wrote:
>
> hi, developers.
>
> Can someone help me? thanks very much !!
Help you how exactly. As I stated your are up to step 2 of the how to
contribute process. If you have a suggested fix for the bug then put
that in an email as described.
Thanks,
David
>
> -- 原始邮件 --
> *发件人:* "David Holmes";
> *发送时间:* 2019年9月5日(星期四) 中午1:44
> *收件人:* "未来阳光"<2217232...@qq.com>;"core-libs-dev" d...@openjdk.java.net>;
> *主题:* Re: what to do next to fix JDK-8230557. thanks
>
> On 5/09/2019 3:35 pm, 未来阳光 wrote:
> > Hi, leaders.
>
> Hi,
>
> No "leaders" here only developers :)
>
> >
> > A few days ago, I report a bug in core lib[1]. According to the
> contribute document[2], I had send oca to oracle andmy name has
> been listed onoca[3].
>
> Welcome aboard!
>
> > But I still can't push my changes to jdk, can someone tell me how to
> do next? thanks very match!!
>
> You can't push anything until you become a Committer and before that you
> have to become an Author. The steps for contributing are outlined here:
>
> http://openjdk.java.net/contribute/
>
> and you would seem to be up to step 2. :)
>
> Cheers,
> David
>
> >
> >
> >
> >
> > [1]https://bugs.openjdk.java.net/browse/JDK-8230557
> >
> > [2]http://openjdk.java.net/contribute/
> > [3]https://www.oracle.com/technetwork/community/oca-486395.html
> >
> >
> >
> >
> >
> > --原始邮件--
> > 发件人:"Bug Report
> Notification" > 发送时间:2019年9月5日(星期四) 凌晨3:33
> > 收件人:"未来阳光"<2217232...@qq.com;
> >
> > 主题:Update Notification: Bug Report - JDK-8230557
> >
> >
> >
> >
> [This is an automated response. Please do not
> reply.]
> > Dear Java Developer,
> > We have finished evaluating your report and have assigned it a Bug
> ID: JDK-8230557. The issue is visible on bugs.java.com at the following
> url JDK-8230557.
> > To provide more information about this issue,
> click here.
> > We work to resolve the issues that are submitted to
> us according to their impact to the community as a whole, and make no
> promises as to the time or release in which a bug might be fixed. If
> this issue has a significant impact on your project you may want to
> consider using one of the technical support offerings available at
> Oracle Support.
> > Regards,
> > Java Developer Support
> >
> >
> >
> >
> >
> > Java SE
> > Java SE Documentation
> > Java SE Downloads
> > Java Developer Forums
> > Oracle Java SE Advanced
> > Bug Database
> >
> Copyright © Oracle and/or
> its affiliates. All rights reserved.
> >
> Terms of Use | Privacy
> >
回复： 回复： what to do next to fix JDK-8230557. thanks
Thanks very much.
BUG-LINK:https://bugs.openjdk.java.net/browse/JDK-8230557
Describe:
the return type of the method BitSet#size is int, so the method may return a
negative value in some case, for example, will return -2147483648.
```
BitSet bitSet = new BitSet(Integer.MAX_VALUE);
for (int i = 0; i < Integer.MAX_VALUE - 1000; i++) {
bitSet.set(i);
}
System.out.println(bitSet.size());
```
EXPECTED:2147483648, butACTUAL:-2147483648.
FIX
I have put the patch in the attachment of the mail.
--原始邮件--
发件人:"David Holmes"http://openjdk.java.net/contribute/
and you would seem to be up to step 2. :)
Cheers,
David
[1]https://bugs.openjdk.java.net/browse/JDK-8230557
[2]http://openjdk.java.net/contribute/
[3]https://www.oracle.com/technetwork/community/oca-486395.html
--nbsp;原始邮件nbsp;--
发件人:nbsp;"Bug Report
Notification"
