Integrated: 8353175: Eliminate double iteration of stream in FieldDescriptor reinitialization

[Radim Vansa]

On Fri, 28 Mar 2025 11:03:29 GMT, Radim Vansa <rvansa at openjdk.org> wrote:

> On the reproducer https://bugs.openjdk.org/secure/attachment/113985/CCC.java my local testing shows these numbers:
> 
> ### JDK-17
> 
> $ hyperfine -w 5 -r 10 '/path/to/jdk-17/bin/java -cp /tmp/ CCC'
> Benchmark 1: /path/to/jdk-17/bin/java -cp /tmp/ CCC
>   Time (mean ± σ):      32.5 ms ±   0.9 ms    [User: 27.5 ms, System: 10.6 ms]
>   Range (min … max):    31.1 ms …  33.7 ms    10 runs
> 
> ### JDK-25 before the change applied
> 
> $ hyperfine -w 5 -r 10 '/path/to/jdk-25/build/linux-x86_64-server-release/images/jdk/bin/java -cp /tmp/ CCC'
> Benchmark 1: /path/to/jdk-25/build/linux-x86_64-server-release/images/jdk/bin/java -cp /tmp/ CCC
>   Time (mean ± σ):     101.6 ms ±   1.5 ms    [User: 96.8 ms, System: 14.6 ms]
>   Range (min … max):    99.0 ms … 104.5 ms    10 runs
> 
> ### JDK-25 with this patch
> 
> $ hyperfine -w 5 -r 10 '/path/to/jdk-25/build/linux-x86_64-server-release/images/jdk/bin/java -cp /tmp/ CCC'
> Benchmark 1: /path/to/jdk-25/build/linux-x86_64-server-release/images/jdk/bin/java -cp /tmp/ CCC
>   Time (mean ± σ):      75.8 ms ±   1.2 ms    [User: 69.8 ms, System: 16.0 ms]
>   Range (min … max):    73.8 ms …  78.2 ms    10 runs

This pull request has now been integrated.

Changeset: f169fc5a
Author:    Radim Vansa <rvansa at openjdk.org>
Committer: Johan Sjölen <jsjolen at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/f169fc5a99ee2b485e156c043134ab76b7e5ebd9
Stats:     31 lines in 5 files changed: 1 ins; 11 del; 19 mod

8353175: Eliminate double iteration of stream in FieldDescriptor reinitialization

Reviewed-by: jsjolen, shade, fparain

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PR: https://git.openjdk.org/jdk/pull/24290