RFR: 8355636: Reuse StringBuilder in printStackTrace [v7]

[Shaojin Wen]

On Sat, 26 Apr 2025 22:42:08 GMT, Shaojin Wen <swen at openjdk.org> wrote:

>> In the Throwable::printStackTrace method, StringBuilder is created multiple times to build String. By sharing StringBuilder to build String, object allocation and copying are reduced.
>> 
>> In the scenario without suppressed and ourCause, unused IdentityHashMap is not created.
>> 
>> Through these optimizations, the performance of `new Exception().printStackTrace()` can be improved by about 10%.
>
> Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/java.base/share/classes/java/lang/Throwable.java
>   
>   Co-authored-by: Hendrik Schick <30866028+ky0n at users.noreply.github.com>

Because more than one Reviewer disagrees with the changes in this PR, I have closed this PR. Thank you for the reviewers who spent time on this PR. Thank you for your time.

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PR Comment: https://git.openjdk.org/jdk/pull/24864#issuecomment-2834284078