[Vm-dev] Multi-Image Sista VM?

[Robert]

Hi Clément,

On 5/2/20 2:47 PM, Clément Béra wrote:

> On Sat, May 2, 2020 at 8:06 PM Robert <robert.withers at pm.me> wrote:
>
>> On 5/1/20 2:59 PM, Clément Béra wrote:
>>
>>> The Hydra VM from Igor was doing exactly that.
>>
>> Stellar! Could we reintegrate with the latest squeak.cog.spur?
>
> Hydra was a fork of the pre-stack VM. I don't know where is the code. Igor may be able to answer. Ask him.

Do you have Igor's email? I will ask.

> As Tim said, it's not clear there is a high benefit from running many image on 1 VM vs multiple images, each on their VM. One advantage could be the speed of communication between the images. However, it's possible to have a byte array on a Posix Shared Memory section (Pavel had made some FFI bindings to do that) that is shared between multiple images. I'm sure with a clever design one could share more than just a byte array. With a shared memory section and external semaphores, it's not clear there are good use-cases that would require multiple images on 1 VM.

I see your and Tim's point here. When asked I have always reported that the way to take advantage of multiple cores is to run multiple images on their own VM. The realm of actor mobility I have not worked on.

Actor Mobility: I think it works just like a eukaryotic cell. with proteins produced through the ribosome and ER, then packaged for delivery with a network motif, and sent through the Golgi Apparatus to be delivered then unpackaged. Normally an Actor is not passByCopy, but a remoteERef is sent abroad. To convert a passByReference object into a passByCopy, serialize it into bytes and wrap it in a package, which is passByCopy. Send it forth, unpackaged remotely, it becomes a passByReference Actor again. Use this to communicate between VM/image/Vat/eventLoop.

>>> The Actor model in Newspeak is also somewhat similar to that, though part of the image is shared between threads.
>>
>> I believe the Newspeak Actors are implemented with local capabilities, from ELib, just as my CapabilitiesLocal package. DoIt:
>>
>>> Installer ss project: 'Cryptography'; install: 'CapabilitiesLocal'.
>>
>> works. Both implement a ELib Promise system with async resolution and resolved promise reactor invocation.
>>
>> Would you be able to say a few words about their use of shared memory, please? As well, what could you mention about their use of promises, regarding Ease of use, understandable code, tips & tricks with promises?
>
> I think Ryan could answer in a better way.

Did you mean to copy Ryan? I would definitely like to hear of NewSpeak in this regard.

> My understand is that NewSpeak have value objects, which are immutable, and such objects can be shared between actors, including classes, methods and so on.
> Not sure about promise. Ryan, can you answer?

Value objects are immutable, thus sharable. Hmmm. Thinks about that.

K, r

>> K, r
>>
>>> Not sure what is the status of these projects though.
>>>
>>> On Wed, Apr 29, 2020 at 8:43 PM Robert <robert.withers at pm.me> wrote:
>>>
>>>>
>>>> I have not read about this anywhere I can remember. Would it be possible to run two images on one VM?
>>>>
>>>> Preggo,
>>>>
>>>> Robertotini
>>>>
>>>> Sent from ProtonMail Mobile
>>>
>>> --
>>>
>>> Clément Bérahttps://clementbera.github.io/
>>> https://clementbera.wordpress.com/
>>
>> --
>> Kindly,
>> Robert
>
> --
>
> Clément Bérahttps://clementbera.github.io/
> https://clementbera.wordpress.com/

--
Kindly,
Robert
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