On Wed, 3 Apr 2024 08:43:26 GMT, Oli Gillespie <ogillespie at openjdk.org> wrote:
>> Improve performance of SecureRandom constructor by backporting (both clean) two changes:
>>
>> 1. [JDK-8280970](https://bugs.openjdk.org/browse/JDK-8280970) removes some unused code in Provider.java. This is not really functionally needed, but it changes the same areas of code and makes the actual performance fix apply cleanly.
>> 2. [JDK-8324646](https://bugs.openjdk.org/browse/JDK-8324646) is the actual performance fix - avoiding Class.forName calls in every construction.
>>
>> Note - because of the unused code still present in JDK17, there is actually an alternative fix which makes use of it, which is very simple:
>>
>>
>> diff --git a/src/java.base/share/classes/java/security/Provider.java b/src/java.base/share/classes/java/security/Provider.java
>> index af8ebeeda57..28bf642d0c8 100644
>> --- a/src/java.base/share/classes/java/security/Provider.java
>> +++ b/src/java.base/share/classes/java/security/Provider.java
>> @@ -1851,7 +1851,7 @@ public abstract class Provider extends Properties {
>> null : constructorParameter.getClass();
>> } else {
>> ctrParamClz = cap.constructorParameterClassName == null?
>> - null : Class.forName(cap.constructorParameterClassName);
>> + null : cap.getConstructorParameterClass(); // actually make use of the cached class!
>> if (constructorParameter != null) {
>> if (ctrParamClz == null) {
>> throw new InvalidParameterException
>>
>>
>> This has the same performance benefits as making the two backports. But, it means 17 will be diverged from later versions, and I think the backported fix is cleaner overall.
>>
>> Benchmark results (`make test TEST=micro:org.openjdk.bench.java.security.SecureRandomBench`):
>>
>>
>> Before: 2614 ± 127 ns/op
>> After: 2150 ± 116 ns/op
>
> Oli Gillespie 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 remote-tracking branch 'origin/master' into backport-8324646-class-for-name-3
> - Backport 8ef918d6678437a5b351b172bb4cf144eeaa975f
> - Backport 63e11cfa3f887515ca36ab5147c3e6fa540978d3
Waiting for next release to ask approval, since this is similar in nature to https://bugs.openjdk.org/browse/JDK-8324648.
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PR Comment: https://git.openjdk.org/jdk17u-dev/pull/2310#issuecomment-2089991306