gistfile1.clj

(def ^ThreadLocal stack-depth (ThreadLocal.))

(def ^Executor overflow-protection-pool
  (let [cnt (atom 0)]
    (Executors/newCachedThreadPool
      (thread-factory #(str "manifold-overflow-protection-pool-" (swap! cnt inc))))))

(def ^:const max-depth 50)

(defmacro without-overflow [& body]
  `(let [depth# (.get stack-depth)
         depth'# (if (nil? depth#) 0 depth#)
         f# (fn [] ~@body)]
     (if (> depth'# max-depth)
       (do
         (.execute overflow-protection-pool ^Runnable f#)
         nil)
       (try
         (.set stack-depth (unchecked-inc (unchecked-long depth'#)))
         (f#)
         (finally
           (when (nil? depth#)
             (.set stack-depth nil)))))))