OCaml fails with SEGV instead of exception Stack_overflow

segv_stackovfl.ml

(*
OCaml fails with SEGV instead of exception Stack_overflow
- by Keigo IMAI <keigo.imai@gmail.com>

ocamlopt -g -thread -I +threads unix.cmxa threads.cmxa segv_stackovfl.ml -o a.out
ulimit -s 8192
./a.out 540000
 *)

let rec run_forever x = 
  List.iter (fun () -> x) []; (* alloc closure to ensure context switching *)
  run_forever ()

let stack_eater limit  = 
  let rec loop i = 
    if i<limit then begin
      loop (i+1); (* non tail-call *)
      ignore ();
    end else begin
      run_forever (); (* stack is almost full. now run into infinite context-switching (which will cause SEGV) *)
    end
  in
  loop 0

(* search for (stack limit) - 32k *)
let rec loop i =
  begin try
    stack_eater i
  with
    | Stack_overflow -> 
      Printf.fprintf stderr "Stack overflow at loop limit %d. try next!\n" i;
  end;
  loop (i-50)

let loop_count = int_of_string (Sys.argv.(1))
;;

(* run another thread to enable context switching *)
Thread.create (fun () -> ()) ()
;;

loop loop_count
;;