-;;;; tests of the system's ability to catch resource exhaustion errors
+;;;; tests of the system's ability to catch resource exhaustion problems
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;; While most of SBCL is derived from the CMU CL system, the test
;;;; files (like this one) were written from scratch after the fork
;;;; from CMU CL.
-;;;;
+;;;;
;;;; This software is in the public domain and is provided with
;;;; absolutely no warranty. See the COPYING and CREDITS files for
;;;; more information.
(cl:in-package :cl-user)
\f
;;; Prior to sbcl-0.7.1.38, doing something like (RECURSE), even in
-;;; safe code, would crash the entire Lisp process. Now it should
-;;; signal an error in a context where the soft stack limit has been
-;;; relaxed enough that the error can be handled.
-(locally
- (declare (optimize safety))
- (defun recurse () (recurse) (recurse))
- (ignore-errors (recurse)))
-\f
-;;; success
-(quit :unix-status 104)
+;;; safe code, would crash the entire Lisp process. Then the soft
+;;; stack checking was introduced, which checked (in safe code) for
+;;; stack exhaustion at each lambda.
+
+;;; Post 0.7.6.1, this was rewritten to use mprotect()-based stack
+;;; protection which does not require lisp code to check anything,
+;;; and works at all optimization settings. However, it now signals a
+;;; STORAGE-CONDITION instead of an ERROR.
+
+(defun recurse ()
+ (recurse)
+ (recurse))
+
+(defvar *count* 100)
+
+;;; Base-case: detecting exhaustion
+(assert (eq :exhausted
+ (handler-case
+ (recurse)
+ (storage-condition (c)
+ (declare (ignore c))
+ :exhausted))))
+
+;;; Check that non-local control transfers restore the stack
+;;; exhaustion checking after unwinding -- and that previous test
+;;; didn't break it.
+(let ((exhaust-count 0)
+ (recurse-count 0))
+ (tagbody
+ :retry
+ (handler-bind ((storage-condition (lambda (c)
+ (declare (ignore c))
+ (if (= *count* (incf exhaust-count))
+ (go :stop)
+ (go :retry)))))
+ (incf recurse-count)
+ (recurse))
+ :stop)
+ (assert (= exhaust-count recurse-count *count*)))
+
+;;; Check that we can safely use user-provided restarts to
+;;; unwind.
+(let ((exhaust-count 0)
+ (recurse-count 0))
+ (block nil
+ (handler-bind ((storage-condition (lambda (c)
+ (declare (ignore c))
+ (if (= *count* (incf exhaust-count))
+ (return)
+ (invoke-restart (find-restart 'ok))))))
+ (loop
+ (with-simple-restart (ok "ok")
+ (incf recurse-count)
+ (recurse)))))
+ (assert (= exhaust-count recurse-count *count*)))
+
+;;; OK!