On Thu, 6 Jan 2022 16:38:05 GMT, Claes Redestad <[email protected]> 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 313:
>
>> 311: // getParameterTypes().
>> 312: if (!genericInfo) {
>> 313: return getSharedParameterTypes();
>
> Since this returns the trusted array it delegates responsibility to the
> callers of `getAllGenericParameterTypes` to not mutate or further expose/leak
> the parameter type array. This needs to at least be called out in the method
> specification. The comment here needs to be updated, as well. Is the added
> fragility in this case worth the performance win?
I agree about the spec and comment. I think we have nothing to worry about in
this case as `Executable` is sealed and `getAllGenericParameterTypes()` is
package-private, so it never gets out of JDK codebase. As of its current usage
we only read from returned `Type[]`. Lot's of frameworks utilize reflection, so
I think we should try to make it as fast as possible
-------------
PR: https://git.openjdk.java.net/jdk/pull/6782
