[External] : Re: jvmci return array

[Fotios Kounelis]

Hello,

I have this PR ( https://github.com/fotiskoun/jdk11u-dev/pull/1 ) for 
OpenJDK11, where I try to create a function 
(JVMCIRuntime::object_hash_get) in jvmciRuntime.cpp to return an int[] 
array.

Could you please further assist me if the code works as expected or has 
any logical issues (Tom and Doug cc'ed in this email, already gave me 
some much appreciated hints!)?

Best regards,

Fotis

On 19/01/2022 12:57, Fotios Kounelis wrote:
>
> Hello,
>
> Please find the pull request in the following link: 
> https://github.com/fotiskoun/jdk11u-dev/pulls
>
> As you can see in the commit tab, this pull request contains only the 
> hash_get function, as the rest of my logic is already in the master tab.
>
> To quickly describe what my general changes in jvmciRuntime.cpp do: I 
> want to create two native functions, a hash_put and a hash_get. The 
> arguments of hash_put() are 2 int[] arrays and their sizes and the 
> behavior is to add these arrays in a local hash map. Respectively, the 
> hash_get() has an int[] array as argument and by searching the map, 
> using the argument as key, returns an array from the map.
>
> You could also have a look at hash_put for more and let me know if 
> there is something wrong about it, too.
>
> Best regards,
>
> Fotis
>
> On 18/01/2022 22:40, Douglas Simon wrote:
>> I think we’re going to be able to better help if you put up a PR on GitHub (preferably a PR on your personal fork ofhttps://github.com/openjdk/jdk). That way, there’s no need to guess at missing details of your problem.
>>
>> -Doug
>>
>>> On 19 Jan 2022, at 08:31, Fotios Kounelis<foths.kounelhs at gmail.com>  wrote:
>>>
>>> Hi Tom,
>>>
>>> Thank you for your reply. My bad example was an attempt to use jni in the HotSpot internals. What I am trying to do is: a function returning an int[] array, filled with values of another existing array.
>>>
>>> So, my function 1) needs to return void 2) have an oop obj initialized with new_intArray 3) fill the values using int_at_put(0...size-1, arrayWithValues[0...size-1]) and 4) use the set_vm_result() to return my array.
>>>
>>> I am not sure what you meant by "proper unpacking logic by a stub caller" for the set_vm_result, as in the same file the common use is something like "thread->set_vm_resutl(obj)", initializing just the oop obj properly with a new_typeArray.
>>>
>>> I would appreciate a quick example in case the above is not how it should work.
>>>
>>> Thank you for your time!
>>>
>>> I couldn't find (or maybe I didn't understand) the set*ArrayRegion initialization in the jni.cpp with the macros, that is why I didn't mention it above.
>>>
>>> Best regards,
>>>
>>> Fotis
>>>
>>> On 18/01/2022 21:15, Tom Rodriguez wrote:
>>>> proper unpacking logic by a stub caller