From william.bruschi at gmail.com  Sat Jul  3 13:16:52 2010
From: william.bruschi at gmail.com (William Bruschi)
Date: Sat, 3 Jul 2010 09:16:52 -0400
Subject: [cl-prevalence-devel] Opening the transaction log - Clozure CL
Message-ID: <AANLkTilyM7SmfaHtnI6_b_FxvuFaDb-iPpoRfagm1RA2@mail.gmail.com>

The Clozure CL implementation has added additional keywords to OPEN,
including the :SHARING keyword which controls the access to the stream
by multiple threads. The default value is :PRIVATE, which allows
access to only the thread that created the stream.  More info here:
http://openmcl.clozure.com/manual/chapter9.1.html#CCL-Stream-Extensions

I was using cl-prevalence as a backend for a Weblocks application when
I stumbled upon thread locking errors while accessing the site with
multiple browsers. Setting :SHARING to nil fixed my problem.

Should this be the default behavior for cl-prevalence? After skimming
the code, it appears cl-prevalence has it's own locking mechanisms,
making Clozure's extra keyword arguments unnecessary. I also noticed
in the TODO file that porting to ccl is on the list.

In case anyone is curious, here's how to reproduce the error in
Weblocks:

1. Create a new project as outlined in the bottom of
http://trac.common-lisp.net/cl-weblocks/wiki/UserManual

2. Edit you init-session.lisp file to this:

(defun init-user-session (root)
  (setf (widget-children root)
	(list (make-grid-edit))))

(defclass thing ()
  ((id :initform nil
       :initarg :id
       :accessor thing-id
       :type (or null integer))
   (name :initform nil
	 :initarg :name
	 :accessor thing-name)))

(defun make-grid-edit ()
  (make-instance 'gridedit
		 :data-class 'thing))

3. Open the site using two different browsers. Add a record using each
browser. The second time you add a record, you receive this error:

SIMPLE-ERROR: Stream #<BASIC-FILE-CHARACTER-OUTPUT-STREAM
("/<path-to-file>/transaction-log.xml"/15 ISO-8859-1) #x1987FB3E> is
private to #<PROCESS Hunchentoot worker (client: 127.0.0.1:47448)(14)
[Reset] #x1983AA9E>



From sky at viridian-project.de  Sun Jul  4 12:27:16 2010
From: sky at viridian-project.de (Leslie P. Polzer)
Date: Sun, 4 Jul 2010 14:27:16 +0200 (CEST)
Subject: [cl-prevalence-devel] Opening the transaction log - Clozure CL
In-Reply-To: <AANLkTilyM7SmfaHtnI6_b_FxvuFaDb-iPpoRfagm1RA2@mail.gmail.com>
References: <AANLkTilyM7SmfaHtnI6_b_FxvuFaDb-iPpoRfagm1RA2@mail.gmail.com>
Message-ID: <5b27391d5b7186dc573846128122ff3c.squirrel@mail.stardawn.org>


William Bruschi wrote:

> I was using cl-prevalence as a backend for a Weblocks application when
> I stumbled upon thread locking errors while accessing the site with
> multiple browsers. Setting :SHARING to nil fixed my problem.
>
> Should this be the default behavior for cl-prevalence? After skimming
> the code, it appears cl-prevalence has it's own locking mechanisms,
> making Clozure's extra keyword arguments unnecessary. I also noticed
> in the TODO file that porting to ccl is on the list.

Yes, please submit a patch to cl-prevalence and I shall apply
it immediately.

  Leslie




From sky at viridian-project.de  Mon Jul  5 15:59:09 2010
From: sky at viridian-project.de (Leslie P. Polzer)
Date: Mon, 5 Jul 2010 17:59:09 +0200 (CEST)
Subject: [cl-prevalence-devel] Patch for serialization of arbitrary data
In-Reply-To: <1276256099.2978.8.camel@krzys-desktop.home>
References: <1276223419.9933.1.camel@krzys-desktop.home>
	<e843a0d137adf86ad919e22516afdb07.squirrel@mail.stardawn.org>
	<1276256099.2978.8.camel@krzys-desktop.home>
Message-ID: <22533a84722f4ba8c41331ce540660fe.squirrel@mail.stardawn.org>


Krzysztof Drewniak wrote:

> --- src/serialization/xml.lisp.old	2010-06-10 20:50:24.000000000 -0500
> +++ src/serialization/xml.lisp	2010-06-10 21:24:34.000000000 -0500
> @@ -196,6 +196,12 @@
>                      (write-string "</SLOT>" stream)))
>  	(write-string "</OBJECT>" stream)))))
>
> +;;anything we don't know about
> +(defmethod serialize-xml-internal (object stream serialization-state)
> +  (declare (ignore serialization-state))
> +  (write-string "<ARBITRARY>" stream)
> +  (print object stream)
> +  (write-string "</ARBITRARY>" stream))
>
>  ;;;; DESERIALIZATION
>
> @@ -283,6 +289,11 @@
>      (declare (ignore name attributes parent-seed seed))
>      nil))
>
> +(defmethod deserialize-xml-finish-element-aux ((name (eql :arbitrary))
> +						attributes parent-seed seed)
> +  (declare (ignore name attributes parent-seed))
> +  (read (make-string-input-stream seed)))
> +

I'm not sure whether this one is good. We're mixing XML and SEXP
serialization.

Do you have a specific use case?

  Leslie




From sky at viridian-project.de  Mon Jul  5 15:59:48 2010
From: sky at viridian-project.de (Leslie P. Polzer)
Date: Mon, 5 Jul 2010 17:59:48 +0200 (CEST)
Subject: [cl-prevalence-devel] 2D arrays
In-Reply-To: <1276255377.2978.6.camel@krzys-desktop.home>
References: <1276255377.2978.6.camel@krzys-desktop.home>
Message-ID: <10026ac7ffc6b0c7b0fba5f90338f211.squirrel@mail.stardawn.org>


Krzysztof Drewniak wrote:
> Is there any major problems with getting 2D arrays (sequences of
> sequences) serialized? (I'm working on a game and trying to find a
> serialization libraryt that does what I need)

cl-store doesn't support this by any chance?

  Leslie