RFR: 8259008: ArithmeticException was thrown at "Monitor Cache Dump" on HSDB [v4]

[Chris Plummer]

On Tue, 26 Jan 2021 07:44:19 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> Yasumasa Suenaga has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains seven commits:
>> 
>>  - Update comments for ObjectMonitorIterator
>>  - Merge remote-tracking branch 'upstream/master' into JDK-8259008
>>  - Update copyright year
>>  - Remove unused code
>>  - Fix comments
>>  - Merge
>>  - 8259008: ArithmeticException was thrown at "Monitor Cache Dump" on HSDB
>
> Hi Yasumasa,
> 
> It looks good to me.
> I have one minor question.
> 
> This loop in the test is a little bit confusing as it has not more than one iteration:
> 55             while (itr.hasNext()) {
> 56                 ObjectMonitor mon = (ObjectMonitor)itr.next();
> 57                 Oop oop = heap.newOop(mon.object());
> 58                 System.out.println("Monitor found: " + oop.getKlass().getName().asString());
> 59                 return;
> 60             }
> Would it better to replace it with if-statement?
> 
> Thanks,
> Serguei

I'd say that's a bug, and probably what was meant is to do a `println` for every monitor found, not just the first one. So what you would want then is to bracket the `while` loop with `if (itr.hasNext()) {` and move the `return` outside the `while` loop but still inside the `if` block.

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PR: https://git.openjdk.java.net/jdk/pull/1910