New candidate JEP: 412: Foreign Function & Memory API (Incubator)

[Gerard Ziemski]

hi,

I read this JEP only once so far, but one thing that I immediately noticed was whether MethodType is really necessary when constructing a MethodHandle, or whether that info can be inferred from FunctionDescriptor as in this given example:


MethodHandle qsort = CLinker.getInstance().downcallHandle(
        LibraryLookup.ofDefault().lookup("qsort").get(),
        MethodType.methodType(void.class, MemoryAddress.class, long.class,
                              long.class, MemoryAddress.class),
        FunctionDescriptor.ofVoid(C_POINTER, C_LONG, C_LONG, C_POINTER)
);

Seems to me that FunctionDescriptor and MethodType describe the same layout?


cheers

> On Apr 22, 2021, at 1:27 PM, mark.reinhold at oracle.com wrote:
> 
> https://openjdk.java.net/jeps/412
> 
>  Summary: Introduce an API by which Java programs can interoperate with
>  code and data outside of the Java runtime. By efficiently invoking
>  foreign functions (i.e., code outside the JVM), and by safely accessing
>  foreign memory (i.e., memory not managed by the JVM), the API enables
>  Java programs to call native libraries and process native data without
>  the brittleness and danger of JNI.
> 
> - Mark