* bug#10581: exit-hook is undocumented and is not called from a non-interactive environment
@ 2012-01-22 19:58 Andrew Psaltis
2012-01-23 2:08 ` Ian Price
2012-02-05 11:50 ` Andy Wingo
0 siblings, 2 replies; 5+ messages in thread
From: Andrew Psaltis @ 2012-01-22 19:58 UTC (permalink / raw)
To: 10581
Currently using guile version 1.8.8. I have been told that this also
affects the current upstream version as well.
My current project involves using a C library that has some
initialization and cleanup functions.
First:
The library initialization part is well-handled, but I could not find
a way to do the library cleanup part. After doing some web searches,
I found an answer in "exit-hook", except that it was not clear from
the Guile reference manual that it existed. It should probably be
documented a little more clearly.
Second:
When I write a scheme script that adds some function to exit-hook, it
is not invoked from a non-interactive call to guile. I have a file
test.scm that looks like so:
(add-hook! exit-hook (lambda () (display "bye\n")))
In an interactive environment:
$ guile -l test.scm
guile> (exit)
bye
$
In a non-interactive environment:
$ guile -s test.scm
$
Nothing is printed. As far as I can tell, exit-hook should be made
available in a non-interactive environment so that modules loading
libraries can cleanup easily.
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#10581: exit-hook is undocumented and is not called from a non-interactive environment
2012-01-22 19:58 bug#10581: exit-hook is undocumented and is not called from a non-interactive environment Andrew Psaltis
@ 2012-01-23 2:08 ` Ian Price
2012-02-05 11:50 ` Andy Wingo
1 sibling, 0 replies; 5+ messages in thread
From: Ian Price @ 2012-01-23 2:08 UTC (permalink / raw)
To: Andrew Psaltis; +Cc: 10581
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Andrew Psaltis <ampsaltis@gmail.com> writes:
> Second:
> When I write a scheme script that adds some function to exit-hook, it
> is not invoked from a non-interactive call to guile. I have a file
> test.scm that looks like so:
>
> (add-hook! exit-hook (lambda () (display "bye\n")))
>
> In an interactive environment:
>
> $ guile -l test.scm
> guile> (exit)
> bye
> $
>
> In a non-interactive environment:
> $ guile -s test.scm
> $
>
> Nothing is printed. As far as I can tell, exit-hook should be made
> available in a non-interactive environment so that modules loading
> libraries can cleanup easily.
Assuming exit-hook is supposed to do this, and I would presume it is
meant to. I have a patch which will implement this for
stable-2.0. Basically, I wrap everything in a large catch, and when
guile gets a 'quit exception it runs the exit hooks before throwing the
exception again.
As far as I can see, this covers the case where guile exits normally
either by use of quit/exit, or just by finishing the script. It does
_not_ perform the cleanup if guile quits because of an uncaught
exception, but if someone thinks this is desirable, it should be a
matter of changing the catch.
I'm not quite sure how to add a test case for this though.
--
Ian Price
"Programming is like pinball. The reward for doing it well is
the opportunity to do it again" - from "The Wizardy Compiled"
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From baaf226cb91a41de66b7dc663c433c67f1c0f0e5 Mon Sep 17 00:00:00 2001
From: Ian Price <ianprice90@googlemail.com>
Date: Sun, 22 Jan 2012 19:47:16 +0000
Subject: [PATCH] Run exit-hook when scripts finish normally.
* module/ice-9/command-line.scm (compile-shell-switches): Wrap the
body of the output expression in a catch for `quit' exceptions, so
that we can run the `exit-hook'.
---
module/ice-9/command-line.scm | 68 +++++++++++++++++++++-------------------
1 files changed, 36 insertions(+), 32 deletions(-)
diff --git a/module/ice-9/command-line.scm b/module/ice-9/command-line.scm
index 8aed74e..e33fac8 100644
--- a/module/ice-9/command-line.scm
+++ b/module/ice-9/command-line.scm
@@ -385,38 +385,42 @@ If FILE begins with `-' the -s switch is mandatory.
`(;; It would be nice not to load up (ice-9 control), but the
;; default-prompt-handler is nontrivial.
(@ (ice-9 control) %)
- (begin
- ;; If we didn't end with a -c or a -s and didn't supply a -q, load
- ;; the user's customization file.
- ,@(if (and interactive? (not inhibit-user-init?))
- '((load-user-init))
- '())
-
- ;; Use-specified extensions.
- ,@(map (lambda (ext)
- `(set! %load-extensions (cons ,ext %load-extensions)))
- user-extensions)
-
- ;; Add the user-specified load path here, so it won't be in
- ;; effect during the loading of the user's customization file.
- ,@(map (lambda (path)
- `(set! %load-path (cons ,path %load-path)))
- user-load-path)
-
- ;; Put accumulated actions in their correct order.
- ,@(reverse! out)
-
- ;; Handle the `-e' switch, if it was specified.
- ,@(if entry-point
- `((,entry-point (command-line)))
- '())
- ,(if interactive?
- ;; If we didn't end with a -c or a -s, start the
- ;; repl.
- '((@ (ice-9 top-repl) top-repl))
- ;; Otherwise, after doing all the other actions
- ;; prescribed by the command line, quit.
- '(quit)))))
+ (catch 'quit
+ (lambda ()
+ ;; If we didn't end with a -c or a -s and didn't supply a -q, load
+ ;; the user's customization file.
+ ,@(if (and interactive? (not inhibit-user-init?))
+ '((load-user-init))
+ '())
+
+ ;; Use-specified extensions.
+ ,@(map (lambda (ext)
+ `(set! %load-extensions (cons ,ext %load-extensions)))
+ user-extensions)
+
+ ;; Add the user-specified load path here, so it won't be in
+ ;; effect during the loading of the user's customization file.
+ ,@(map (lambda (path)
+ `(set! %load-path (cons ,path %load-path)))
+ user-load-path)
+
+ ;; Put accumulated actions in their correct order.
+ ,@(reverse! out)
+
+ ;; Handle the `-e' switch, if it was specified.
+ ,@(if entry-point
+ `((,entry-point (command-line)))
+ '())
+ ,(if interactive?
+ ;; If we didn't end with a -c or a -s, start the
+ ;; repl.
+ '((@ (ice-9 top-repl) top-repl))
+ ;; Otherwise, after doing all the other actions
+ ;; prescribed by the command line, quit.
+ '(quit)))
+ (lambda args
+ (run-hook exit-hook)
+ (apply throw args)))))
(if (pair? args)
(begin
--
1.7.7.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* bug#10581: exit-hook is undocumented and is not called from a non-interactive environment
2012-01-22 19:58 bug#10581: exit-hook is undocumented and is not called from a non-interactive environment Andrew Psaltis
2012-01-23 2:08 ` Ian Price
@ 2012-02-05 11:50 ` Andy Wingo
2012-02-05 19:20 ` Andrew Psaltis
2012-07-06 11:21 ` Andy Wingo
1 sibling, 2 replies; 5+ messages in thread
From: Andy Wingo @ 2012-02-05 11:50 UTC (permalink / raw)
To: Andrew Psaltis; +Cc: 10581
Hi Andrew,
On Sun 22 Jan 2012 20:58, Andrew Psaltis <ampsaltis@gmail.com> writes:
> After doing some web searches, I found an answer in "exit-hook",
> except that it was not clear from the Guile reference manual that it
> existed. It should probably be documented a little more clearly.
It's not documented at all, actually. It was added in 1998 to
boot-9.scm with the following comment:
;;; This hook is run at the very end of an interactive session.
;;;
(define exit-hook (make-hook))
It has not been changed since then.
> When I write a scheme script that adds some function to exit-hook, it
> is not invoked from a non-interactive call to guile.
Indeed, as the comment notes.
I think it's fair to say that this is a historical interface, and that
it probably shouldn't be changed.
Why not use atexit(), if you need to clean up the C library? Just
wondering.
Andy
--
http://wingolog.org/
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#10581: exit-hook is undocumented and is not called from a non-interactive environment
2012-02-05 11:50 ` Andy Wingo
@ 2012-02-05 19:20 ` Andrew Psaltis
2012-07-06 11:21 ` Andy Wingo
1 sibling, 0 replies; 5+ messages in thread
From: Andrew Psaltis @ 2012-02-05 19:20 UTC (permalink / raw)
To: Andy Wingo; +Cc: 10581
On Sun, Feb 5, 2012 at 06:50, Andy Wingo <wingo@pobox.com> wrote:
> Hi Andrew,
>
> On Sun 22 Jan 2012 20:58, Andrew Psaltis <ampsaltis@gmail.com> writes:
>
>> After doing some web searches, I found an answer in "exit-hook",
>> except that it was not clear from the Guile reference manual that it
>> existed. It should probably be documented a little more clearly.
>
> It's not documented at all, actually. It was added in 1998 to
> boot-9.scm with the following comment:
>
> ;;; This hook is run at the very end of an interactive session.
> ;;;
> (define exit-hook (make-hook))
>
> It has not been changed since then.
>
Ah, yes.
>> When I write a scheme script that adds some function to exit-hook, it
>> is not invoked from a non-interactive call to guile.
>
> Indeed, as the comment notes.
>
> I think it's fair to say that this is a historical interface, and that
> it probably shouldn't be changed.
>
> Why not use atexit(), if you need to clean up the C library? Just
> wondering.
>
That would be because I forgot that it existed. I probably should
just use that instead.
Thanks.
~Andrew
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#10581: exit-hook is undocumented and is not called from a non-interactive environment
2012-02-05 11:50 ` Andy Wingo
2012-02-05 19:20 ` Andrew Psaltis
@ 2012-07-06 11:21 ` Andy Wingo
1 sibling, 0 replies; 5+ messages in thread
From: Andy Wingo @ 2012-07-06 11:21 UTC (permalink / raw)
To: 10581-done
Hi,
Closing out this bug, as it seems that the current situation shouldn't
be changed, and also that atexit sounds sufficient. Please open a new
report if you still have issues :)
Regards,
Andy
--
http://wingolog.org/
^ permalink raw reply [flat|nested] 5+ messages in thread
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2012-01-22 19:58 bug#10581: exit-hook is undocumented and is not called from a non-interactive environment Andrew Psaltis
2012-01-23 2:08 ` Ian Price
2012-02-05 11:50 ` Andy Wingo
2012-02-05 19:20 ` Andrew Psaltis
2012-07-06 11:21 ` Andy Wingo
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