summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--test-suite/tests/guardians.test50
1 files changed, 45 insertions, 5 deletions
diff --git a/test-suite/tests/guardians.test b/test-suite/tests/guardians.test
index e6a4203a2..756747fe6 100644
--- a/test-suite/tests/guardians.test
+++ b/test-suite/tests/guardians.test
@@ -19,8 +19,18 @@
;;;; 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.
@@ -74,6 +84,25 @@
(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))
+
+ ;; 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
@@ -117,6 +146,7 @@
(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
@@ -130,6 +160,7 @@
(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
@@ -144,6 +175,7 @@
(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
@@ -177,7 +209,8 @@
(gc)
(let ((p (cons #f #f)))
(g p)
- (vector-set! v 0 p))
+ (vector-set! v 0 p)
+ (set! p #f)) ;; clear refs left on the stack
(if (not (eq? (g) #f))
(throw 'unresolved)
(begin
@@ -192,7 +225,8 @@
(gc)
(let ((p (cons #f #f)))
(g p)
- (vector-set! v 0 p))
+ (vector-set! v 0 p)
+ (set! p #f)) ;; clear refs left on the stack
(begin
(gc)
(if (not (equal? (g) (cons #f #f)))
@@ -206,7 +240,11 @@
(pass-if "element of guarded weak vector gets collected"
(let ((g (make-guardian))
- (v (weak-vector (cons #f #f))))
+ (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.
+ (vector-set! v 0 (cons #f #f))
+
(g v)
(gc)
(if (equal? (vector-ref v 0) (cons #f #f))
@@ -250,7 +288,8 @@
(gc)
(let ((p (cons #f #f)))
(g p)
- (g p))
+ (g p)
+ (set! p #f)) ;; clear refs left on the stack
(if (not (eq? (g) #f))
(throw 'unresolved)
(begin
@@ -265,7 +304,8 @@
(gc)
(let ((p (cons #f #f)))
(g p)
- (h p))
+ (h p)
+ (set! p #f)) ;; clear refs left on the stack
(if (not (eq? (g) #f))
(throw 'unresolved)
(begin