[EMAIL PROTECTED] (Ludovic Courtès) writes:
> Hello,
>
> That "no duplicate" test in `popen.test' leaves a zombie behind it [0].
> The fix would be to `waitpid' the process created by `open-input-pipe'
> (see attached patch), but that makes it hang, waiting for "sleep 999" to
> complete.
I've attached an alternative possible solution, using feedback from
the parent to the child to avoid needing the long sleep.
Unfortunately, though, I didn't manage to observe the zombie process
with the test as it was before. (How do I do this on GNU/Linux?) So
I don't really know whether this is a significant improvement.
> I'm not sure whether it's an indication that the bug was caught, or
> rather an indication that the test is broken, especially since I don't
> fully understand the bug that it's trying to catch.
If waitpid fixes it, doesn't that point to the test being broken?
> I would appreciate feedback on this since it's tempting to remove it
> altogether for all the harm it's done. ;-)
It seems a worthwhile test to me. I'd rather work on a tricky
test like this, than on a report of a problem in the context of a
whole application (but which eventually boiled down to the same
thing).
I'm also interested in the forking/threads issue (which is now fixed,
if I've understood the cited thread correctly), and wouldn't want to
remove a test that covered that, unless we can devise a more specific
test for just that issue.
Regards,
Neil
Index: test-suite/tests/popen.test
===================================================================
RCS file: /cvsroot/guile/guile/guile-core/test-suite/tests/popen.test,v
retrieving revision 1.3.2.2
diff -u -r1.3.2.2 popen.test
--- test-suite/tests/popen.test 25 Aug 2006 01:21:39 -0000 1.3.2.2
+++ test-suite/tests/popen.test 17 Mar 2008 22:54:07 -0000
@@ -81,12 +81,15 @@
(let* ((pair (pipe))
(port (with-error-to-port (cdr pair)
(lambda ()
- (open-input-pipe
- "exec 1>/dev/null; echo closed 1>&2; exec 2>/dev/null; sleep 999")))))
+ (open-input-output-pipe
+ "exec 1>/dev/null; echo closed 1>&2; exec 2>/dev/null; read")))))
(close-port (cdr pair)) ;; write side
- (and (char? (read-char (car pair))) ;; wait for child to do its thing
- (char-ready? port)
- (eof-object? (read-char port))))))
+ (let ((result (and (char? (read-char (car pair))) ;; wait for child to do its thing
+ (char-ready? port)
+ (eof-object? (read-char port)))))
+ (display "hello!\n" port)
+ (close-pipe port)
+ result))))
;;
;; open-output-pipe
