RFR(T): 8252125: add an "inflating" entry to the "table" of bit patterns in share/oops/markWord.hpp

[Daniel D. Daugherty]

Hi Thomas,

Thanks for the review.

Dan


On 8/21/20 4:34 AM, Thomas Schatzl wrote:
> Hi,
>
> On 20.08.20 22:56, Daniel D. Daugherty wrote:
>> Greetings,
>>
>> I have a trivial fix to add more clarification to markWord bit patterns.
>>
>> Here's the bug report:
>>
>>      JDK-8252125 add an "inflating" entry to the "table" of bit 
>> patterns in
>>                  share/oops/markWord.hpp
>>      https://bugs.openjdk.java.net/browse/JDK-8252125
>>
>> And here's the context diff for the trivial change itself:
>>
>> $ hg diff -r qparent
>> diff -r 8f73aeccb27c src/hotspot/share/oops/markWord.hpp
>> --- a/src/hotspot/share/oops/markWord.hpp    Thu Aug 20 11:12:00 2020 
>> -0700
>> +++ b/src/hotspot/share/oops/markWord.hpp    Thu Aug 20 16:39:11 2020 
>> -0400
>> @@ -84,12 +84,13 @@
>>   //    [header      | 0 | 01]  unlocked           regular object header
>>   //    [ptr             | 10]  monitor            inflated lock 
>> (header is wapped out)
>>   //    [ptr             | 11]  marked             used to mark an 
>> object
>> +//    [0 ............ 0| 00]  inflating          inflation in progress
>>   //
>>   //    We assume that stack/thread pointers have the lowest two bits 
>> cleared.
>>   //
>> -//  - INFLATING() is a distinguished markword value that is used when
>> -//    inflating an existing stack-lock into an ObjectMonitor. See below
>> -//    for is_being_inflated() and INFLATING().
>> +//  - INFLATING() is a distinguished markword value of all zeros 
>> that is
>> +//    used when inflating an existing stack-lock into an ObjectMonitor.
>> +//    See below for is_being_inflated() and INFLATING().
>>
>>   class BasicLock;
>>   class ObjectMonitor;
>>
>> Thanks, in advance, for any comments, questions or suggestions.
>>
>
>   lgtm and trivial.
>
> Thomas