RFR(S): 8132723, 8132724: Add tests which check that soft/weak references to humongous objects should work correctly

[Kirill Zhaldybin]

Jon,

Thank you very much for reviewing this.
I will add the enhancement you proposed in a separate fix.

Regards, Kirill

On 09.12.2015 01:41, Jon Masamitsu wrote:
> Kirill,
>
> Test looks good.
>
> One enhancement you might consider (not necessarily for this
> integration) is to print out "adr" and the g1 region for "adr" if the
> test fails.  I'm guessing you can get the g1 region from WB.  If the
> test fails
> and you have the list of g1 regions (it would be in the hs_err log file),
> the first thing you might want to do is look up the g1 region to
> see if there is anything unexpected about it.  Just something to
> consider.
>
> Jon
>
>
> On 11/24/2015 11:05 AM, Kirill Zhaldybin wrote:
>> Hi!
>>
>> Could you please review the following patch that adds a test that
>> checks that soft/weak references to humongous objects work correctly?
>>
>> The test checks that weak and soft references behave correspondingly
>> to actual object behavior:
>> 1. If an object is collected a weak/soft reference .get() should
>> return null.
>> 2. If an object is not collected a weak/soft reference .get() should
>> not return null.
>>
>> Two White Box API methods were added:
>> 1. g1BelongsToHumongousRegion which checks that address belongs to
>> humongous region
>> 2. g1BelongsToFreeRegion which checks that address belongs to free region
>> These methods do not  impact G1 performance/stability since they don't
>> change anything in G1 execution.
>>
>> The only used method from gc/testlibrary is waitTillCMCFinished, which
>> is under review here -
>> http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2015-November/015643.html
>>
>>
>> CR: https://bugs.openjdk.java.net/browse/JDK-8132723
>>     https://bugs.openjdk.java.net/browse/JDK-8132724
>>
>> Webrev:
>>     main:
>> http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8132724/webrev.02/main/
>>     hotspot:
>> http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8132724/webrev.02/hotspot/
>>
>>
>> Thank you.
>>
>> Regards, Kirill
>