Executing a function with a timeout

Question

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

(with-timeout 5000
 (do-somthing))

Unless do-so

Answer 1

It's a quite a breeze using clojure's channel facilities https://github.com/clojure/core.async

require respective namespace

(:require [clojure.core.async :refer [>! alts!! timeout chan go]])

the function wait takes a timeout [ms], a function [f] and optional parameters [args]

(defn wait [ms f & args]
  (let [c (chan)]
    (go (>! c (apply f args)))
    (first (alts!! [c (timeout ms)]))))

third line pops off the call to f to another thread. fourth line consumes the result of the function call or (if faster) the timeout.

consider the following example calls

(wait 1000 (fn [] (do (Thread/sleep 100) 2)))
=> 2

but

(wait 50 (fn [] (do (Thread/sleep 100) 2)))
=> nil