dtype ffi segfault on linux

[phronmophobic]

On linux, I was able to reliably cause a segfault when using dt-ffi/define-library-interface. The crash seems to be caused by the calling a native function after its corresponding com.sun.jna.NatilveLibrary instance has been garbage collected.

The following will crash:

(dt-ffi/define-library-interface
    {:answer {:rettype :int32}}
    :libraries ["answer"])

(defn -main [& args]
  (println (answer))

  (while true
    (System/gc)
    (println (answer))
    (Thread/sleep 1000)))

Workaround: Holding a reference to the NativeLibrary instance prevents the crash:

;; hang on to lib instance
(def libanswer (com.sun.jna.NativeLibrary/getInstance "answer"))
(dt-ffi/define-library-interface
    {:answer {:rettype :int32}}
    :libraries ["answer"])

(defn -main [& args]
  (println (answer))

  (while true
    (System/gc)
    (println (answer))
    (Thread/sleep 1000)))

Instructions and code: https://github.com/phronmophobic/dtype-ffi-linux-repro/