bug#61350: Eglot over Tramp freezes with large project

[Jim Porter]

On 3/15/2023 2:49 PM, João Távora wrote:
> SLY, jsonrpc.el, and other code is synchronous as well (the completion
> API is synch, as you well know).  `accept-p-o` + a filter that invokes
> a closure that throws out of the loop is a great way to do this.
> See jsonrpc-request, for example.  No JUST-THIS-ONE, and has
> been working fine in many forms since Emacs 24.3 AFAIK.

Assuming I understand the context here correctly, this sort of thing is 
part of why Chris Wellons' emacs-aio package uses 'run-at-time' for 
handling resolved promises[1]:

> If the result is ready call the callback in the next event loop turn using 
> run-at-time. This is important because it keeps all the asynchronous components 
> isolated from one another. They won’t see each others’ frames on the call 
> stack, nor frames from aio. This is so important that the Promises/A+ 
> specification is explicit about it.

While a solution specific to the problem in this bug likely doesn't 
require an entire asynchrony framework, if we get one into Emacs, it 
should definitely support this case. (That said, a lot of the discussion 
from this is probably best left to the emacs-devel thread so as not to 
cause too much distraction... :))

[1] https://nullprogram.com/blog/2019/03/10/