Integrated: 8324646: Avoid Class.forName in SecureRandom constructor

[Oli Gillespie]

On Wed, 24 Jan 2024 15:25:28 GMT, Oli Gillespie <ogillespie at openjdk.org> wrote:

> Avoid expensive `Class.forName` call when constructing Providers such as `SecureRandom` which take constructor parameters. This can easily be cached in EngineDescription (this cache already existed before, it was removed in [JDK-8280970](https://bugs.openjdk.org/browse/JDK-8280970) as unused, I'm bringing it back unchanged to support this new usage).
> 
> Benchmark results on my Linux x86 host show around a 20% reduction in time to create a new `SecureRandom` instance. Most of the remaining overhead is due to a failing constructor lookup - see [JDK-8324648](https://bugs.openjdk.org/browse/JDK-8324648).
> 
> 
> Before
> newSecureRandom  avgt  2930 ± 50  ns/op
> 
> After
> newSecureRandom  avgt  2400 ± 33  ns/op
> 
> 
> I have seen multiple real-world applications which call `new SecureRandom()` on the hot path, so I believe efficiency here is important.

This pull request has now been integrated.

Changeset: 8ef918d6
Author:    Oli Gillespie <ogillespie at openjdk.org>
Committer: Weijun Wang <weijun at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/8ef918d6678437a5b351b172bb4cf144eeaa975f
Stats:     61 lines in 2 files changed: 47 ins; 1 del; 13 mod

8324646: Avoid Class.forName in SecureRandom constructor

Reviewed-by: shade, weijun

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PR: https://git.openjdk.org/jdk/pull/17559