4 ms·

> Honestly erlang isn't really preemptive either, it just has a lot of hidden yield points. At some level this is true of all systems - you can't yield in the

> Honestly erlang isn't really preemptive either, it just has a lot of hidden yield points. At some level this is true of all systems - you can't yield in the middle of a `mov`, for example. But as Erlang is interpreted it doesn't rely on yield points. The caveat is that it does if you use CFFI. > You can use ets tables to coordinate processes (but don't). Yeah I'm sure there are endless ways to bypass the intended use of Erlang, I don't think it's really important. This is way different from Go where data is trivially shared across a channel. > The raison d'etre of erlang processes is not really message passing concurrency, it's failure domain definition and failure domain bundling Yes, this is true. The foundation of Erlang is based on earlier research that Armstrong cites in his thesis paper, such as the persistent process and transaction as the basis of system resiliency. But it's not a coincidence he landed on actors to express those things.

dnautics 5y ago
Erlang is compiled to bytecode, and the yield points are between each instruction sort of. > The caveat is that it does if you use CFFI. No shit, I wrote a huge FFI library for the BEAM (that even implements a yielding system.that interops with erlang's yields), that's a huge part of my point about the beam not really being preemptive. > But it's not a coincidence he landed on actors to express those things. Yes, that's my point. In erlang the conceptual arrow goes (resiliency => not-really-but-kinda-like-actors). In these other systems, or at least the ones I've peeked at, like pony and bastion the logic goes (actors => underpants gnomes => something like erlang). It's completely backwards.
- staticassertion 5y ago
  > Erlang is compiled to bytecode, and the yield points are between each instruction sort of. This is basically what I'm saying... at some point nothing is preemptive ie: at the instruction level. > that's a huge part of my point about the beam not really being preemptive. OK but I think that's really semantics, it doesn't really matter though. You are right that BEAM can't yield within an instruction or during FFI. If you think that means it isn't preemptive, ok, but as I said I think at some point you end up with "nothing is preemptive" and then "why do we have the word preemptive" and then "because it's useful to describe systems like BEAM". > Yes, that's my point. In erlang the conceptual arrow goes (resiliency => not-really-but-kinda-like-actors). In these other systems, or at least the ones I've peeked at, like pony and bastion the logic goes (actors => underpants gnomes => something like erlang). It's completely backwards. Sure, actors aren't "the point". They just satisfy important properties that are necessary for resiliency. Pony takes a very very different approach from Erlang. Bastion seems closer. I don't think "distance from Erlang" is really important or interesting though. Inspiration from Erlang is present in many of these systems, whether they re-implement the exact concepts or not.

dnautics 5y ago

Erlang is compiled to bytecode, and the yield points are between each instruction sort of. > The caveat is that it does if you use CFFI. No shit, I wrote a huge FFI library for the BEAM (that even implements a yielding system.that interops with erlang's yields), that's a huge part of my point about the beam not really being preemptive. > But it's not a coincidence he landed on actors to express those things. Yes, that's my point. In erlang the conceptual arrow goes (resiliency => not-really-but-kinda-like-actors). In these other systems, or at least the ones I've peeked at, like pony and bastion the logic goes (actors => underpants gnomes => something like erlang). It's completely backwards.

staticassertion 5y ago
> Erlang is compiled to bytecode, and the yield points are between each instruction sort of. This is basically what I'm saying... at some point nothing is preemptive ie: at the instruction level. > that's a huge part of my point about the beam not really being preemptive. OK but I think that's really semantics, it doesn't really matter though. You are right that BEAM can't yield within an instruction or during FFI. If you think that means it isn't preemptive, ok, but as I said I think at some point you end up with "nothing is preemptive" and then "why do we have the word preemptive" and then "because it's useful to describe systems like BEAM". > Yes, that's my point. In erlang the conceptual arrow goes (resiliency => not-really-but-kinda-like-actors). In these other systems, or at least the ones I've peeked at, like pony and bastion the logic goes (actors => underpants gnomes => something like erlang). It's completely backwards. Sure, actors aren't "the point". They just satisfy important properties that are necessary for resiliency. Pony takes a very very different approach from Erlang. Bastion seems closer. I don't think "distance from Erlang" is really important or interesting though. Inspiration from Erlang is present in many of these systems, whether they re-implement the exact concepts or not.