abort in ZForwarding

[Per Liden]

Pushed

/Per

On 04/10/2019 11:22 AM, Erik Österlund wrote:
> Hi Stuart,
> 
> Good catch. Looks good.
> 
> Thanks,
> /Erik
> 
> On 2019-04-09 11:52, Stuart Monteith wrote:
>> Thanks Per.
>>
>> I've opened JDK-8222180 and put the patch here:
>>      http://cr.openjdk.java.net/~smonteith/8222180/webrev/
>>
>> It passes the gtests and runs fine with -XX:+ZVerifyForwarding enabled.
>>
>> BR,
>>     Stuart
>>
>>
>> On Mon, 8 Apr 2019 at 21:18, Per Liden <per.liden at oracle.com> wrote:
>>> Hi Stuart,
>>>
>>> On 04/08/2019 06:39 PM, Stuart Monteith wrote:
>>> [...]
>>>> This resolves the issue:
>>>>
>>>> diff -r 6eb8c555644a src/hotspot/share/gc/z/zForwarding.cpp
>>>> --- a/src/hotspot/share/gc/z/zForwarding.cpp    Mon Apr 08 09:44:49 
>>>> 2019 +0100
>>>> +++ b/src/hotspot/share/gc/z/zForwarding.cpp    Mon Apr 08 17:30:18 
>>>> 2019 +0100
>>>> @@ -69,6 +69,11 @@
>>>>        // Check for duplicates
>>>>        for (ZForwardingCursor j = i + 1; j < _entries.length(); j++) {
>>>>          const ZForwardingEntry other = at(&j);
>>>> +      if (!other.populated()) {
>>>> +         // Skip empty entries
>>>> +         continue;
>>>> +       }
>>>> +
>>>>          guarantee(entry.from_index() != other.from_index(), 
>>>> "Duplicate from");
>>>>          guarantee(entry.to_offset() != other.to_offset(), 
>>>> "Duplicate to");
>>>>        }
>>>>
>>>> Have you already encountered this, shall I create a bug+  patchset ?
>>> Ah, yes. That looks like an oversight after JDK-8221540. Feel free to
>>> create a bug and send a patch to hotspot-gc-dev. I'll sponsor it.
>>>
>>> /Per
>