;;;; guardians.test --- test suite for Guile Guardians -*- scheme -*-
;;;; Jim Blandy <jimb@red-bean.com> --- July 1999
;;;;
-;;;; Copyright (C) 1999, 2001 Free Software Foundation, Inc.
+;;;; Copyright (C) 1999, 2001, 2006, 2014 Free Software Foundation, Inc.
;;;;
-;;;; This program is free software; you can redistribute it and/or modify
-;;;; it under the terms of the GNU General Public License as published by
-;;;; the Free Software Foundation; either version 2, or (at your option)
-;;;; any later version.
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
;;;;
-;;;; This program is distributed in the hope that it will be useful,
+;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;;;; GNU General Public License for more details.
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;;;; Lesser General Public License for more details.
;;;;
-;;;; You should have received a copy of the GNU General Public License
-;;;; along with this software; see the file COPYING. If not, write to
-;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
-;;;; Boston, MA 02111-1307 USA
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
;;; These tests make some questionable assumptions.
+;;;
;;; - They assume that a GC will find all dead objects, so they
;;; will become flaky if we have a generational GC.
+;;;
+;;; - More generally, when a weakly referenced object doesn't disappear as
+;;; expected, it's hard to tell whether that's because of a guardian bug of
+;;; because a reference to it is being held somewhere, e.g., one some part
+;;; of the stack that hasn't been overwritten. Thus, most tests cannot
+;;; fail, they can just throw `unresolved'. We try hard to clear
+;;; references that may have been left on the stacks (see "clear refs left
+;;; on the stack" lines).
+;;;
;;; - They assume that objects won't be saved by the guardian until
;;; they explicitly invoke GC --- in other words, they assume that GC
;;; won't happen too often.
-(gc)
+(define-module (test-guardians)
+ :use-module (test-suite lib)
+ :use-module (ice-9 documentation)
+ :use-module (ice-9 weak-vector))
+
+\f
+;;;
+;;; miscellaneous
+;;;
+
+(define (documented? object)
+ (not (not (object-documentation object))))
+
-(define g1 (make-guardian))
-(define not-g1-garbage (list 'not-g1-garbage))
-(g1 not-g1-garbage)
-(g1 (list 'g1-garbage))
-(pass-if "g1-garbage not collected yet" (equal? (g1) #f))
(gc)
-(pass-if "g1-garbage saved" (equal? (g1) '(g1-garbage)))
;;; Who guards the guardian?
+
+;;; Note: We use strings rather than symbols because symbols are usually
+;;; ``interned'', i.e., kept in a weakly-keyed hash table, thus making them
+;;; inappropriate for the tests below. Furthermore, we use `string-copy' in
+;;; order to make sure that no string is kept around in the interpreter
+;;; unwillingly (e.g., in the source-property weak hash table).
+
(gc)
(define g2 (make-guardian))
-(g2 (list 'g2-garbage))
+(g2 (list (string-copy "g2-garbage")))
(define g3 (make-guardian))
-(g3 (list 'g3-garbage))
+(g3 (list (string-copy "g3-garbage")))
(g3 g2)
(pass-if "g2-garbage not collected yet" (equal? (g2) #f))
(pass-if "g3-garbage not collected yet" (equal? (g3) #f))
(if saved
(begin
(cond
- ((equal? saved '(g3-garbage)) (set! seen-g3-garbage #t))
+ ((equal? saved (list (string-copy "g3-garbage")))
+ (set! seen-g3-garbage #t))
((procedure? saved) (set! seen-g2 saved))
- (else (set! seen-something-else #t)))
+ (else (pk 'junk saved) (set! seen-something-else #t)))
(loop)))))
- (pass-if "g3-garbage saved" seen-g3-garbage)
- (pass-if "g2-saved" (procedure? seen-g2))
+ (pass-if "g3-garbage saved" (or seen-g3-garbage (throw 'unresolved)))
+ (pass-if "g2-saved" (or (procedure? seen-g2) (throw 'unresolved)))
(pass-if "nothing else saved" (not seen-something-else))
- (pass-if "g2-garbage saved" (and (procedure? seen-g2)
- (equal? (seen-g2) '(g2-garbage)))))
+
+ ;; FIXME: The following test fails because the guardian for `g2-garbage'
+ ;; disappared from the weak-car guardian list of `g2-garbage' right before
+ ;; `g2-garbage' was finalized (in `finalize_guarded ()'). Sample session
+ ;; (compiled with `-DDEBUG_GUARDIANS'):
+ ;;
+ ;; guile> (define g (make-guardian))
+ ;; guile> (let ((g2 (make-guardian)))
+ ;; (format #t "g2 = ~x~%" (object-address g2))
+ ;; (g2 (string-copy "foo"))
+ ;; (g g2))
+ ;; g2 = 81fde18
+ ;; guile> (gc)
+ ;; finalizing guarded 0x827f6a0 (1 guardians)
+ ;; guardian for 0x827f6a0 vanished
+ ;; end of finalize (0x827f6a0)
+ ;; finalizing guarded 0x81fde18 (1 guardians)
+ ;; end of finalize (0x81fde18)
+
+ (pass-if "g2-garbage saved" (or (and (procedure? seen-g2)
+ (equal? (seen-g2)
+ (list (string-copy
+ "g2-garbage"))))
+ (throw 'unresolved))))
+
+(with-test-prefix "standard guardian functionality"
+
+ (with-test-prefix "make-guardian"
+
+ (pass-if "documented?"
+ (documented? make-guardian))
+
+ (pass-if "returns procedure"
+ (procedure? (make-guardian)))
+
+ (pass-if "returns new procedure each time"
+ (not (equal? (make-guardian) (make-guardian)))))
+
+ (with-test-prefix "empty guardian"
+
+ (pass-if "returns #f"
+ (eq? ((make-guardian)) #f))
+
+ (pass-if "returns always #f"
+ (let ((g (make-guardian)))
+ (and (eq? (g) #f)
+ (begin (gc) (eq? (g) #f))
+ (begin (gc) (eq? (g) #f))))))
+
+ (with-test-prefix "guarding independent objects"
+
+ (pass-if "guarding immediate"
+ (let ((g (make-guardian)))
+ (g #f)
+ (and (eq? (g) #f)
+ (begin (gc) (eq? (g) #f))
+ (begin (gc) (eq? (g) #f)))))
+
+ (pass-if "guarding non-immediate"
+ (let ((g (make-guardian)))
+ (gc)
+ (g (cons #f #f))
+ (cons 'clear 'stack) ;; clear refs left on the stack
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (if (not (equal? (g) (cons #f #f)))
+ (throw 'unresolved)
+ (eq? (g) #f))))))
+
+ (pass-if "guarding two non-immediates"
+ (let ((g (make-guardian)))
+ (gc)
+ (g (cons #f #f))
+ (g (cons #t #t))
+ (cons 'clear 'stack) ;; clear refs left on the stack
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (let ((l (list (g) (g))))
+ (if (not (or (equal? l (list (cons #f #f) (cons #t #t)))
+ (equal? l (list (cons #t #t) (cons #f #f)))))
+ (throw 'unresolved)
+ (eq? (g) #f)))))))
+
+ (pass-if "re-guarding non-immediates"
+ (let ((g (make-guardian)))
+ (gc)
+ (g (cons #f #f))
+ (cons 'clear 'stack) ;; clear refs left on the stack
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (let ((p (g)))
+ (if (not (equal? p (cons #f #f)))
+ (throw 'unresolved)
+ (begin
+ (g p)
+ (set! p #f)
+ (gc)
+ (if (not (equal? (g) (cons #f #f)))
+ (throw 'unresolved)
+ (eq? (g) #f)))))))))
+
+ (pass-if "guarding living non-immediate"
+ (let ((g (make-guardian))
+ (p (cons #f #f)))
+ (g p)
+ (if (not (eq? (g) #f))
+ (throw 'fail)
+ (begin
+ (gc)
+ (not (eq? (g) p)))))))
+
+ (with-test-prefix "guarding weakly referenced objects"
+
+ (pass-if "guarded weak vector element gets returned from guardian"
+ (let ((g (make-guardian))
+ (v (weak-vector #f)))
+ (gc)
+ (let ((p (cons #f #f)))
+ (g p)
+ (weak-vector-set! v 0 p)
+ (set! p #f)) ;; clear refs left on the stack
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (if (not (equal? (g) (cons #f #f)))
+ (throw 'unresolved)
+ (eq? (g) #f))))))
+
+ (pass-if "guarded element of weak vector gets eventually removed from weak vector"
+ (let ((g (make-guardian))
+ (v (weak-vector #f)))
+ (gc)
+ (let ((p (cons #f #f)))
+ (g p)
+ (weak-vector-set! v 0 p)
+ (set! p #f)) ;; clear refs left on the stack
+ (begin
+ (gc)
+ (if (not (equal? (g) (cons #f #f)))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (or (not (weak-vector-ref v 0))
+ (throw 'unresolved))))))))
+
+ (with-test-prefix "guarding weak containers"
+
+ (pass-if "element of guarded weak vector gets collected"
+ (let ((g (make-guardian))
+ (v (weak-vector #f)))
+ ;; Note: We don't pass `(cons #f #f)' as an argument to `weak-vector'
+ ;; otherwise references to it are likely to be left on the stack.
+ (weak-vector-set! v 0 (cons #f #f))
+
+ (g v)
+ (gc)
+ (if (equal? (weak-vector-ref v 0) (cons #f #f))
+ (throw 'unresolved)
+ #t))))
+
+ (with-test-prefix "guarding guardians"
+ #t)
+
+ (with-test-prefix "guarding dependent objects"
+
+ ;; We don't make any guarantees about the order objects are
+ ;; returned from guardians and therefore we skip the following
+ ;; test.
+
+ (if #f
+ (pass-if "guarding vector and element"
+ (let ((g (make-guardian)))
+ (gc)
+ (let ((p (cons #f #f)))
+ (g p)
+ (g (vector p)))
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (if (not (equal? (g) (vector (cons #f #f))))
+ (throw 'unresolved)
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (if (not (equal? (g) (cons #f #f)))
+ (throw 'unresolved)
+ (eq? (g) #f)))))))))))
+
+ (with-test-prefix "guarding objects more than once"
+
+ (pass-if "guarding twice in one guardian"
+ (let ((g (make-guardian)))
+ (gc)
+ (let ((p (cons #f #f)))
+ (g p)
+ (g p)
+ (set! p #f)) ;; clear refs left on the stack
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (or (and (and=> (g) (lambda (o) (equal? o (cons #f #f))))
+ (and=> (g) (lambda (o) (equal? o (cons #f #f)))))
+ (throw 'unresolved))))))
+
+ (pass-if "guarding twice in two guardians"
+ (let ((g (make-guardian))
+ (h (make-guardian)))
+ (gc)
+ (let ((p (cons #f #f)))
+ (g p)
+ (h p)
+ (set! p #f)) ;; clear refs left on the stack
+ (if (not (eq? (g) #f))
+ (throw 'unresolved)
+ (begin
+ (gc)
+ (or (and (and=> (g) (lambda (o) (equal? o (cons #f #f))))
+ (and=> (h) (lambda (o) (equal? o (cons #f #f)))))
+ (throw 'unresolved)))))))
+
+ (with-test-prefix "guarding cyclic dependencies"
+ #t)
+
+ )
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