RFR: 8337505: Footprint and startup regressions up to 20% in GUI apps

[Chen Liang]

On Mon, 28 Oct 2024 21:26:38 GMT, Phil Race <prr at openjdk.org> wrote:

> https://bugs.openjdk.org/browse/JDK-8338677 already improved things for this so that's good.
> 
> This fix adds to it lazy initialisation of VarHandles in StrikeCache at the cost of some extra code.
> Since these VarHandles get used more or less immediately on Linux this new fix won't further improve matters there
> But should help on Mac where they aren't usually needed at startup
> And Windows is somewhere in between.

>From the FFM API pov, we might be able to make the VarHandle lazy, that it contains symbolic information and is fully expanded upon first use, effectively the same as the laziness here. Don't know if this works for FFM, but this is how java lang invoke ones work if they have to initialize classes. If such laziness is implemented, we can always revisit the existing uses later. This patch is fine as long as there is no bad side effects.

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PR Comment: https://git.openjdk.org/jdk/pull/21748#issuecomment-2522095066