RFR: 8287661: Fix and improve BitMap::print_on(outputStream*) [v2]

[Aleksey Shipilev]

On Wed, 1 Jun 2022 15:56:39 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Found these inconvenient during debugging using the `BitMap::print_on`. We pass the `outputStream*` to the method, but do not use it. Also, the output is hard to read for large bitmaps. 
>> 
>> Sample output generated by gtest:
>> 
>> 
>> [0.292s][info][test] Bitmap (0 bits):
>> [0.292s][info][test] Bitmap (128 bits):
>> [0.292s][info][test]     0: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]    64: S....... ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test] Bitmap (1024 bits):
>> [0.292s][info][test]     0: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]    64: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   128: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   192: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   256: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   320: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   384: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   448: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   512: S....... ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   576: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   640: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   704: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   768: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   832: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   896: ........ ........ ........ ........ ........ ........ ........ ........
>> [0.292s][info][test]   960: ........ ........ ........ ........ ........ ........ ........ ........
>> 
>> 
>> It becomes clearer that bits 64 and 512 are set, respectively.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 fastdebug, new gtest
>>  - [x] Linux x86_64 release, new gtest
>
> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8287661-bitmaps-improv
>  - Review comments
>  - Fix

Any other opinions? I'll integrate it otherwise.

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PR: https://git.openjdk.java.net/jdk/pull/8970