A ringing bell:

https://youtu.be/MmrihxFhWJw?t=57

It is a bell sound as the sister comment points out. We found that a multitude of sounds work with negligible difference in perception. The bell however was consistently voted the most comfortable in post trial questionnaire.

We certainly do use both. For example in communication we process socket layer conditions and remote operation results together to synthesize Evacsound's own nomenclature of conditions in distributed operation terms. They are then re-signaled and can be handled by a small set of our wrapper macros and constructs.

Our process/tasks abstraction naturally also uses conditions to handle the lifecycle.

As for restarts you can see their invocations in the last code snippet in the article.

Lots of single mode fiber in redundant loops. In longer tunnels you'd have several technical rooms along that hold the loop ends into L3 switches. Within the loop you have emergency cabinets spaced 125m. Apart from fire extinguishers and emergency phones (often also our products!) they contain some PLCs and L2 switches that distribute signal and PoE to end point devices such as Evacsound or traffic cameras.

Yes it was some of that certainly. I could gauge roughly what kind of effort the problem would take, what kind of constraints it would have to run with and select among the tools I am comfortable with. I read about Erlang but never did anything with it. From what I know though it would not necessarily be better at this job than CL and learning another language on the go was not in the plans.

But isn't it the deal with all programming language choices? Ultimately the only true programming language is machine code, the rest are just abstractions for our wetware's benefit.

Sorry about that, should be up again!

Fortunately it was uneventful, as the idiom is the same as in any other programming language that support them. We used bordeaux-threads package for portability across the implementations.