headers
Jocelyn Fréchot | 16 Mar 2012 22:39
Picon
Favicon

Extension functions re-defining themselves

Hello,

I’d like to report the folling issue I bumped into: in
the cl-opengl-bindings package, extension functions defined with
defglextfun will re-define themselves the first time they are called.
This is somewhat an unexpected and potentially undesirable behavior:
if you store one of those function objects before calling it, it will
compile a new object every time it is funcalled.

Thanks

--

-- 
Jocelyn

_______________________________________________
cl-opengl-devel mailing list
cl-opengl-devel <at> common-lisp.net
http://lists.common-lisp.net/cgi-bin/mailman/listinfo/cl-opengl-devel
Permalink | Reply |
headers
Luís Oliveira | 17 Mar 2012 11:01
Picon
Gravatar

Re: Extension functions re-defining themselves

On Fri, Mar 16, 2012 at 9:39 PM, Jocelyn Fréchot
<jocelyn_frechot <at> yahoo.fr> wrote:
> I’d like to report the folling issue I bumped into: in
> the cl-opengl-bindings package, extension functions defined with
> defglextfun will re-define themselves the first time they are called.
> This is somewhat an unexpected and potentially undesirable behavior:
> if you store one of those function objects before calling it, it will
> compile a new object every time it is funcalled.

At the end of gl/bindings.lisp there's an alternative implementation
of DEFGLEXTFUN that doesn't call compile or redefine anything. Does
that work better for you?

--

-- 
Luís Oliveira
http://r42.eu/~luis/
Permalink | Reply |
headers
Jocelyn Fréchot | 17 Mar 2012 12:28
Picon
Favicon

Re: Extension functions re-defining themselves

On 17/03/2012 11:01, Luís Oliveira wrote:

> At the end of gl/bindings.lisp there's an alternative implementation
> of DEFGLEXTFUN that doesn't call compile or redefine anything. Does
> that work better for you?

I tried this version:

(defmacro defglextfun ((cname lname) return-type &body args)
   (alexandria:with-unique-names (pointer)
     `(let ((,pointer (null-pointer)))
        (defun ,lname ,(mapcar #'car args)
          (when (null-pointer-p ,pointer)
            (setf ,pointer (gl-get-proc-address ,cname))
            (assert (not (null-pointer-p ,pointer)) ()
                    "Couldn't load symbol ~A~%" ,cname)
            (format t "Loaded function pointer for ~A: ~A~%" ,cname ,pointer)
            (push (lambda () (setf ,pointer (null-pointer)))
                  *gl-extension-resetter-list*))
          (foreign-funcall-pointer
           ,pointer
           (:library opengl)
           , <at> (loop for arg in args collect (second arg) collect (first arg))
           ,return-type)))))

However, compilation of gl/funcs.lisp fails due to heap exhaustion
(using SBCL 1.0.55).

--

-- 
Jocelyn
(Continue reading)

Permalink | Reply |
headers
Luís Oliveira | 31 Mar 2012 17:42
Picon
Gravatar

Re: Extension functions re-defining themselves

Hello Jocelyn,

I tried it out as well and got similar results. I also tried using load-time-value for the pointer cache in the hopes that making the DEFUN a top-level form would appease SBCL but that help too much.

Have you tried using a less smart compiler such as CCL ou CLISP?

--
Luís Oliveira
http://r42.eu/~luis

On Mar 17, 2012 11:28 AM, "Jocelyn Fréchot" <jocelyn_frechot <at> yahoo.fr> wrote:
On 17/03/2012 11:01, Luís Oliveira wrote:

At the end of gl/bindings.lisp there's an alternative implementation
of DEFGLEXTFUN that doesn't call compile or redefine anything. Does
that work better for you?

I tried this version:

(defmacro defglextfun ((cname lname) return-type &body args)
 (alexandria:with-unique-names (pointer)
   `(let ((,pointer (null-pointer)))
      (defun ,lname ,(mapcar #'car args)
        (when (null-pointer-p ,pointer)
          (setf ,pointer (gl-get-proc-address ,cname))
          (assert (not (null-pointer-p ,pointer)) ()
                  "Couldn't load symbol ~A~%" ,cname)
          (format t "Loaded function pointer for ~A: ~A~%" ,cname ,pointer)
          (push (lambda () (setf ,pointer (null-pointer)))
                *gl-extension-resetter-list*))
        (foreign-funcall-pointer
         ,pointer
         (:library opengl)
         , <at> (loop for arg in args collect (second arg) collect (first arg))
         ,return-type)))))

However, compilation of gl/funcs.lisp fails due to heap exhaustion
(using SBCL 1.0.55).

--
Jocelyn
_______________________________________________
cl-opengl-devel mailing list
cl-opengl-devel <at> common-lisp.net
http://lists.common-lisp.net/cgi-bin/mailman/listinfo/cl-opengl-devel
Permalink | Reply |
headers
Nikodemus Siivola | 31 Mar 2012 18:02
Gravatar

Re: Extension functions re-defining themselves

On 31 March 2012 18:42, Luís Oliveira <luismbo <at> gmail.com> wrote:

> I tried it out as well and got similar results. I also tried using
> load-time-value for the pointer cache in the hopes that making the DEFUN a
> top-level form would appease SBCL but that help too much.
>
> Have you tried using a less smart compiler such as CCL ou CLISP?

Can you point me at right spot in cl-opengl sources, and provide a
test-case. I think I have an idea...

Cheers,

 -- nikodemus

_______________________________________________
cl-opengl-devel mailing list
cl-opengl-devel <at> common-lisp.net
http://lists.common-lisp.net/cgi-bin/mailman/listinfo/cl-opengl-devel
Permalink | Reply |
headers
Luís Oliveira | 1 Apr 2012 01:11
Picon
Gravatar

Re: Extension functions re-defining themselves

On Sat, Mar 31, 2012 at 5:02 PM, Nikodemus Siivola
<nikodemus <at> random-state.net> wrote:
> Can you point me at right spot in cl-opengl sources, and provide a
> test-case. I think I have an idea...

The code is at:
<https://github.com/luismbo/cl-opengl/tree/sbcl-unfriendly-defglextfun>

The test-case is simply compiling cl-opengl. SBCL will exhaust the
heap while attempting to compile gl/funcs.lisp which contains about
2000 usages of DEFGLEXTFUN.

Cheers,

--

-- 
Luís Oliveira
http://r42.eu/~luis/
Permalink | Reply |
headers
Nikodemus Siivola | 1 Apr 2012 11:01
Gravatar

Re: Extension functions re-defining themselves

On 1 April 2012 02:11, Luís Oliveira <luismbo <at> gmail.com> wrote:

> The code is at:
> <https://github.com/luismbo/cl-opengl/tree/sbcl-unfriendly-defglextfun>
>
> The test-case is simply compiling cl-opengl. SBCL will exhaust the
> heap while attempting to compile gl/funcs.lisp which contains about
> 2000 usages of DEFGLEXTFUN.

Thanks!

Patch attached -- probably not something to merge as-is, since I
commented out a few extensions due to missing/bad types, but this
builds for me on x86-64 using the default 1Gb heap.

Cheers,

 -- nikodemus
Attachment (0001-fix-build-on-SBCL.patch): application/octet-stream, 4245 bytes
_______________________________________________
cl-opengl-devel mailing list
cl-opengl-devel <at> common-lisp.net
http://lists.common-lisp.net/cgi-bin/mailman/listinfo/cl-opengl-devel
Permalink | Reply |
headers
Jocelyn Fréchot | 31 Mar 2012 18:46
Picon
Favicon

Re: Extension functions re-defining themselves

On 31/03/2012 17:42, Luís Oliveira wrote:

> I tried it out as well and got similar results. I also tried using
> load-time-value for the pointer cache in the hopes that making the DEFUN a
> top-level form would appease SBCL but that help too much.
>
> Have you tried using a less smart compiler such as CCL ou CLISP?

No I haven’t. For now I store function symbols rather than objects.
I guess the overhead of funcall-ing them is negligible in my context.

--

-- 
Jocelyn

_______________________________________________
cl-opengl-devel mailing list
cl-opengl-devel <at> common-lisp.net
http://lists.common-lisp.net/cgi-bin/mailman/listinfo/cl-opengl-devel
Permalink | Reply |

Gmane