RFR: 8278461: Use Executable.getSharedParameterTypes() instead of Executable.getParameterTypes() in trusted code

[Сергей Цыпанов]

On Thu, 6 Jan 2022 16:45:09 GMT, Claes Redestad <redestad at openjdk.org> wrote:

>> `Executable.getParameterTypes()` creates a copy of underlying array which is redundant in trusted code when we are sure the action is read-only.
>
> src/java.base/share/classes/java/lang/reflect/Executable.java line 317:
> 
>> 315:             final boolean realParamData = hasRealParameterData();
>> 316:             final Type[] genericParamTypes = getGenericParameterTypes();
>> 317:             final Type[] nonGenericParamTypes = getSharedParameterTypes();
> 
> (If removing these allocations is important, I note that `ConstructorRepository.getGenericParameterTypes()` lacks an equivalent to `getSharedParameterType` for trusted callers)
> 
> Similarly here I'm not sure the win from avoiding the clone is worth delegating the additional responsibility. You could still do this here if you add `.clone()` after `nonGenericParamTypes` on L344

@cl4es Do you think it's worth creating a separate PR for `ConstructorRepository.getGenericParameterTypes()`?

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PR: https://git.openjdk.java.net/jdk/pull/6782