Hi Jakob,

I have asked you several times to comment on the Promise implementation in PromisesLocal, but you have not responded. This is unfortunate.

> Installer ss project: 'Cryptography'; install: 'PromisesLocal'.

Although the Promise defined in Kernel-Processes has #wait protocol, this is really an anathema to Promise-style control flow. The #whenResolved: protocol should be used to register a reactor and no waits should occur.

One issue immediately apparent is that there is no event loop (In the PriorityVat) that secures single-threaded behavior in the promise. In PromisesLocal there is a LocalResolver who forwards all pending #whenResolved: messages to the new reference, on the event-loop Process (calls #redirectEventualMessage:).

See ERef #promiseInVat: for the pair production of an asociation with a PromiseERef and a LocalResolver. There is no equivalent to this in Kernel-Processes.

Promise-style control flow does not use mutexes nor semaphores. So I believe the fundamental model here is misused.

You said:

On 7/23/20 12:57 PM, Jakob Reschke wrote:

> To move away from modal dialogs, nesting the world loop,
> and from writing all the business logic in a promise-style control
> flow

So it is your intention to "move away from promise-style control flow." then I would suggest not using a Promise.

Kindly,
rabbit
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