Question

What would be an idiomatic way of executing a function within a time limit? Something like,

(with-timeout 5000
 (do-somthing))

Unless do-something returns within 5000 throw an exception or return nil.

EDIT: before someone points it out there is,

clojure (with-timeout … macro)

but with that the future keeps executing that does not work in my case.

Answer 1

This isn’t something you can do 100% reliably on the JVM. The only way to stop something after a while is to give it a new thread, and then send that thread an exception when you want it to stop. But their code can catch the exception, or they can spin up another thread that you don’t control, or…

But most of the time, and especially if you control the code that’s being timed out, you can do something like we do in clojail:

If you wanted to make that prettier you could define a macro like

(defmacro with-timeout [time & body]
  `(thunk-timeout (fn [] ~@body) ~time))