tests/exhaust.impure.lisp

   1 ;;;; tests of the system's ability to catch resource exhaustion problems
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; While most of SBCL is derived from the CMU CL system, the test
   7 ;;;; files (like this one) were written from scratch after the fork
   8 ;;;; from CMU CL.
   9 ;;;;
  10 ;;;; This software is in the public domain and is provided with
  11 ;;;; absolutely no warranty. See the COPYING and CREDITS files for
  12 ;;;; more information.
  13
  14 (cl:in-package :cl-user)
  15 \f
  16 ;;; Prior to sbcl-0.7.1.38, doing something like (RECURSE), even in
  17 ;;; safe code, would crash the entire Lisp process. Then the soft
  18 ;;; stack checking was introduced, which checked (in safe code) for
  19 ;;; stack exhaustion at each lambda.
  20
  21 ;;; Post 0.7.6.1, this was rewritten to use mprotect()-based stack
  22 ;;; protection which does not require lisp code to check anything,
  23 ;;; and works at all optimization settings.  However, it now signals a
  24 ;;; STORAGE-CONDITION instead of an ERROR.
  25
  26 (defun recurse ()
  27   (recurse)
  28   (recurse))
  29
  30 (defvar *count* 100)
  31
  32 ;;; Base-case: detecting exhaustion
  33 (assert (eq :exhausted
  34             (handler-case
  35                 (recurse)
  36               (storage-condition (c)
  37                 (declare (ignore c))
  38                 :exhausted))))
  39
  40 ;;; Check that non-local control transfers restore the stack
  41 ;;; exhaustion checking after unwinding -- and that previous test
  42 ;;; didn't break it.
  43 (let ((exhaust-count 0)
  44       (recurse-count 0))
  45   (tagbody
  46      :retry
  47      (handler-bind ((storage-condition (lambda (c)
  48                                          (declare (ignore c))
  49                                          (if (= *count* (incf exhaust-count))
  50                                              (go :stop)
  51                                              (go :retry)))))
  52        (incf recurse-count)
  53        (recurse))
  54      :stop)
  55   (assert (= exhaust-count recurse-count *count*)))
  56
  57 ;;; Check that we can safely use user-provided restarts to
  58 ;;; unwind.
  59 (let ((exhaust-count 0)
  60       (recurse-count 0))
  61   (block nil
  62    (handler-bind ((storage-condition (lambda (c)
  63                                        (declare (ignore c))
  64                                        (if (= *count* (incf exhaust-count))
  65                                            (return)
  66                                            (invoke-restart (find-restart 'ok))))))
  67       (loop
  68        (with-simple-restart (ok "ok")
  69          (incf recurse-count)
  70          (recurse)))))
  71   (assert (= exhaust-count recurse-count *count*)))
  72
  73 ;;; OK!