RFR: JDK-8310502 : Optimization for j.l.Long.fastUUID() [v24]

[Andrey Turbanov]

On Sun, 25 Jun 2023 20:38:28 GMT, 温绍锦 <duke at openjdk.org> wrote:

>> By optimizing the implementation of java.lang.Long#fastUUID, the performance of the java.util.UUID#toString method can be significantly improved.
>> 
>> The following are the test results of JMH: 
>> 
>> Benchmark                     Mode  Cnt      Score      Error   Units
>> UUIDUtilsBenchmark.new       thrpt    5  92676.550 ±  292.213  ops/ms
>> UUIDUtilsBenchmark.original  thrpt    5  37040.165 ± 1023.532  ops/ms
>
> 温绍锦 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   remove JavaLangAccess#fastUUID

src/java.base/share/classes/java/util/UUID.java line 515:

> 513: 
> 514:         try {
> 515:             return jla.newStringNoRepl(buf, StandardCharsets.ISO_8859_1);

in java.base it's better to use `ISO_8859_1.INSTANCE` directly instead of `StandardCharsets.ISO_8859_1`.
See [JDK-8234147](https://bugs.openjdk.org/browse/JDK-8234147)

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PR Review Comment: https://git.openjdk.org/jdk/pull/14578#discussion_r1241889942