[mdergosits]

Wouldn't loop detection be equivalent to solving the halting problem? Obviously a naive approach would be disallow recursion/ mutual recursion, but there are valid use cases for those that may not result in infinite execution

[harlanji]

I helped design a large scale JS execution engine. We used Babel to rewrite code with loops that could be interrupted by our system. Eg. `for(...){mycode();}` would be recompiled to `for(...){if(!running()){halt();}mycode();}`. The technical reason is that tight loops wouldn't respond to SIGINT, if I recall correctly. So while it doesn't stop infinite loops, it can control the program. I wasn't involved in productionizing it.

[duaneb]

Sorry--couldn't be interrupted by SIGINT? That's arguably the point of signals. Does the runtime just queue signals rather than respond in the signal handler itself?

[dllthomas]

As I understand it, this is mutual recursion accross services, which is a much more specific case. Forbidding it may be viable.