Modified Seaside VM

Just looking through Steve Warings Seaside installation notes, I saw that a
modified Dolphin 5 VM is attached. Is it safe to replace my old VM with this
one in general and all suff should continue to work as before? Also when
creating To-Go apps, is the new VM included?

Ciao

...jochen

ok, found info about this in the other seaside docs, VM is experimental.

Now I wonder, if Dolphin will adopt the VisualWorks/Squeak approach for
Continuations in the future?

Found this:
" The semantics of Continuations differ between Squeak/Dolphin when
continuing within a guarded block as Dolphin Continuations create a new
process and terminate the old."

I guess this is the issue fixed in the experimental VM?

Ciao

...Jochen

Hi Jochen,

Jochen Riekhof wrote:

> ... Is it safe to replace my
> old VM with this one in general and all suff should continue to work
> as before?

I have been using the modified VM for the past couple of months and I have
not had any problems with it.

> Also when creating To-Go apps, is the new VM included?

> Now I wonder, if Dolphin will adopt the VisualWorks/Squeak approach
> for Continuations in the future?

My guess for both questions is no, but Blair or Andy would be better able to
answer these questions.

> I guess this is the issue fixed in the experimental VM?

As I understand it, most of the support for Continuations was implemented in
the image. The change to the VM was to enable a process instance to be
correctly copied and to add some safety asserts.

FWIW: I believe that there is work being done on porting Seaside V2.0 to
Dolphin. I am not sure of the status of this port, but there was a fair bit
of work done on Seaside between V0.94 and V2.

Thanks,
Steve

--
Steve Waring
Email: [hidden email]
About: http://www.dolphinharbor.org/dh/harbor/steve.html
Journal: http://www.stevewaring.net/blog/home/index.html

Hi Steve...

> I have been using the modified VM for the past couple of months and I have
> not had any problems with it.

Sounds good!

> My guess for both questions is no, but Blair or Andy would be better able
to
> answer these questions.

Would be nice if they did when they have some time ;-).

> FWIW: I believe that there is work being done on porting Seaside V2.0 to
> Dolphin. I am not sure of the status of this port, but there was a fair
bit
> of work done on Seaside between V0.94 and V2.

Hum, who is working on it? I did not find any refs through google?!

If you have some time, can you look into my "fat clients in dolphin" thread,
please? It seems likely that you know a lot about server side interfacing
with dolphin ;-).

Ciao and thanks!

...Jochen

Jochen Riekhof wrote:
> Hum, who is working on it? I did not find any refs through google?!

Hi Jochen,

I looked into this, and no progress has been made. I know of a couple of
people who are interested in using v2, and if any progress is made on the
port, I will let you know.

Thanks,
Steve

--
Steve Waring
Email: [hidden email]
About: http://www.dolphinharbor.org/dh/harbor/steve.html
Journal: http://www.stevewaring.net/blog/home/index.html

> I know of a couple of
> people who are interested in using v2, and if any progress is made on the
> port, I will let you know.

Great, thanks!
Have a good day!

Ciao

...Jochen

"Steve Waring" <[hidden email]> wrote in message news:<auj0qa$7iufn$[hidden email]>...
> Jochen Riekhof wrote:
> > Hum, who is working on it? I did not find any refs through google?!
>
> Hi Jochen,
>
> I looked into this, and no progress has been made. I know of a couple of
> people who are interested in using v2, and if any progress is made on the
> port, I will let you know.

Steve,

It's interesting to hear that - the only Dolphin user I've talked to
directly is Jeff Odell, but since he was at least contemplating doing
the v2 port himself, I assume he's not who you mean.  If there's any
real interest in Seaside from the Dolphin world, I'd love to hear
about it.

Avi

Hi Avi,

> <snip> If there's any
> real interest in Seaside from the Dolphin world, I'd love to hear
> about it.
>
> Avi

I'm working on a project that is intended to become a web app in say 1/2
year's time and I'm hoping to use Seaside for it. So yes, there is 'real'
interest in it.

Ted
www.tedbracht.co.uk

Avi Bryant wrote:
> It's interesting to hear that - the only Dolphin user I've talked to
> directly is Jeff Odell, but since he was at least contemplating doing
> the v2 port himself, I assume he's not who you mean.  If there's any
> real interest in Seaside from the Dolphin world, I'd love to hear
> about it.

Hi Avi,

Aside from Jeff and Ted, Jerry Bell is also looking to use Seaside for a
couple of his projects.

I think that there would be more interest if the Dolphin port didnt require
a replacement VM. I have been waiting for the next patch from Object-Arts to
see if it included support for Continuations, however I am no longer holding
my breath waiting for it to appear.

If Object-Arts dont release a second patch for V5, hopefully Dolphin6 will
include Continuations, and if nobody else has done the Seaside port by then,
I will have a go at it myself.

Steve

--
Steve Waring
Email: [hidden email]
About: http://www.dolphinharbor.org/dh/harbor/steve.html
Journal: http://www.stevewaring.net/blog/home/index.html

Steve and all

> I think that there would be more interest if the Dolphin port didnt
require
> a replacement VM. I have been waiting for the next patch from Object-Arts
to
> see if it included support for Continuations, however I am no longer
holding
> my breath waiting for it to appear.
>
> If Object-Arts dont release a second patch for V5, hopefully Dolphin6 will
> include Continuations, and if nobody else has done the Seaside port by
then,
> I will have a go at it myself.

Dolphin 6 will include the VM that is necessary to support Continuations. I
suppose we *could* release a revised D5 (we can't use a Live Update patch it
because MSI won't let DLL components be replaced) but we were hoping not to
have to do that. If there is real demand for Seaside under D5 then we might
be persuaded :-)

The next question you're going to ask is when D6 will be available. Well, we
don't know as yet. The aim is for March/April but I'm not going to promise
anything.

Best Regards,

Andy Bower
Dolphin Support
http://www.object-arts.com
---
Are you trying too hard?
http://www.object-arts.com/Relax.htm
---

Andy,

Executive summary: You've "convinced"<g> me that an updated D5 release
(installers on your web site) is a lot of work just to get transparent
Continuations support in D5 with D6 taking shape.  My vote would be to keep
you working on D6, documentation, and bug fixes.  However, there are some
patches that warrant a Live Update patch level, and I have some questions re
MSI.


> Dolphin 6 will include the VM that is necessary to support Continuations.
I
> suppose we *could* release a revised D5 (we can't use a Live Update patch
it
> because MSI won't let DLL components be replaced)

Does it overwrite the change, get confused for the next install, or
something else?  It sounds like people have patched it manually though??  Do
they then also use custom shortcuts vs. the ones that allow MSI to do its
thing before Dolphin runs?  Feel free to describe the real issue if I'm
missing it :)


> but we were hoping not to
> have to do that. If there is real demand for Seaside under D5 then we
might
> be persuaded :-)

I understand why you don't want to do a full release.  However, there are
some other patches that probably should be collected and released as a
patch.  Other than something about generating disp interfaces, I don't
remember what they are, and that's the real problem.  A live update patch
would put them in one place.


> The next question you're going to ask is when D6 will be available.

Snatched right out of my keyboard buffer :)


> Well, we
> don't know as yet. The aim is for March/April but I'm not going to promise
> anything.

Thanks for the ballpark estimate.  What new features can we expect?

Have a good one,

Bill

--
Wilhelm K. Schwab, Ph.D.
[hidden email]

Hi Andy,

Thanks for the info on PL2 and Dolphin6.

Andy Bower wrote:
> Dolphin 6 will include the VM that is necessary to support
> Continuations. I suppose we *could* release a revised D5 (we can't
> use a Live Update patch it because MSI won't let DLL components be
> replaced) but we were hoping not to have to do that. If there is real
> demand for Seaside under D5 then we might be persuaded :-)

I am not sure of what the real demand is, I was only speculating that not
needing to replace the VM may create more demand. In any case, if somebody
really wants it now, it isnt hard to manually switch to the modified VM.

I doubt that I will get the chance to work with Seaside in the next couple
of months, so it suits me to wait for Dolphin 6.

Avi, is Seaside v2 still being experimented with? If so, do you have a
timeframe for a stable v2 release?

Thanks,
Steve

--
Steve Waring
Email: [hidden email]
About: http://www.dolphinharbor.org/dh/harbor/steve.html
Journal: http://www.stevewaring.net/blog/home/index.html

"Bill Schwab" <[hidden email]> wrote in message
news:auva2d$sh0$[hidden email]...

[re: Replacement of MSI installed VM DLL]
> Does it overwrite the change, get confused for the next install, or
> something else?  It sounds like people have patched it manually though??
Do
> they then also use custom shortcuts vs. the ones that allow MSI to do its
> thing before Dolphin runs?  Feel free to describe the real issue if I'm
> missing it :)

The Dolphin lauch executable (at least as of D5) will load the VM DLL in the
following order of by preference:
1) From the directory from which the application (dolphin.exe) was loaded.
2) By instantiating it as a COM object
3) From the standard LoadLibrary() path. Basically this is the app dir (as
(1)), current (or working) directory, windows system directory, windows
directory, any other directories on the PATH. However there are certain
other possibilities on Windows 2000 and XP, refer to MSDN for more info.

Thus simply placing a copy of the new VM in the directory from which one
runs Dolphin.exe is sufficient to cause it to be used. This is how the
continuation VM has been used up to now. However, one is swimming against
the MSI tide here, and any attempt to actually replace the MSI installed
DLL, including re-registering it in a new location, is unlikely to work. The
problem from our point of view is that it would be difficult to guarantee
that patching the DLL by overwriting it or re-registering it would actually
work, which is not very satisfactory and obviously leads to increased
support overhead.

As an aside, the changes to the VM for continuations are really not that
significant, but unfortunately they are necessary because the shallow copy
primitive did not work correctly for "virtual memory" (growable) objects,
such as processes. Other than that the continuation support is implemented
entirely in-image - a lot of the motivation for doing continuations in
Dolphin was to disprove the claim that the old Smalltalk-80 explicit context
model was necessary to support them, and so ideally there should have been
no change needed to the VM, but unfortunately there was a bug.

We have been constructing a PL2 for D5, however we generally wait until
there is a really compelling bug fix before we release a patch level because
of the level of effort (particularly testing) that is required.
[Un]fortunately, there hasn't really been a 5.01 bug serious enought to
mandate an immediate patch, so we have put off the release. This is not a
situation we have ever found ourselves in before :-), butI hope it would be
regarded as a positive endorsement of the improving quality of Dolphin
releases. Anyway, there are now almost 100 (mostly minor) bug fixes and
enhancements pending for PL2, so we will release it early in the new year.

In the meantime if anyone wants to help beta test the patch, let me know and
I will mail it to you.

Regards

Blair

Blair,

> We have been constructing a PL2 for D5, however we generally wait until
> there is a really compelling bug fix before we release a patch level
because
> of the level of effort (particularly testing) that is required.
> [Un]fortunately, there hasn't really been a 5.01 bug serious enought to
> mandate an immediate patch, so we have put off the release. This is not a
> situation we have ever found ourselves in before :-),

Well, if it makes you feel any better, I have found something that doesn't
quite look right.  With that said, I'm not yet certain whether you or I own
it.  I've learned how to reproduce it, and now need to make some time to see
if I can catch it in the act.  It's not going to be the easiest thing to
debug because timing/sequencing will probably turn out to be important
(especially likely if it turns out to be my fault).

I agree that D5 is unusually stable compared to the mainstream.


> butI hope it would be
> regarded as a positive endorsement of the improving quality of Dolphin
> releases. Anyway, there are now almost 100 (mostly minor) bug fixes and
> enhancements pending for PL2, so we will release it early in the new year.

100!!!!!  I had no clue.  Thanks for your efforts.  It indeed sounds like
time for a patch release.


> In the meantime if anyone wants to help beta test the patch, let me know
and
> I will mail it to you.

This is going to be a relatively dry couple of weeks re programming.  I have
a couple of things to fix and otherwise will be spending a lot of time
number crunching and/or working on a presentation.  I'll gladly take a quick
look, or if you are not in a huge hurry, I'll have more time to test in a
couple of weeks.

Have a good one,

Bill

--
Wilhelm K. Schwab, Ph.D.
[hidden email]

"Steve Waring" <[hidden email]> wrote:
>
> Avi, is Seaside v2 still being experimented with? If so, do you have a
> timeframe for a stable v2 release?

Various layers are still being experimented with (for example, I'm
playing right now with a generic way of having running different
sections of a page in independent, backtrackable threads, and we don't
yet have a template system I'm happy with), but I regard the core as
stable.  If you get Session and HtmlRenderer running on Dolphin,
porting any development in the higher layers should be trivial.

I expect to release v2.2 in about a week; this is what I would
recommend basing a port on.  I would predict v2.4 will be in about a
month, and will have the new threading stuff and possibly a new
templating system, but both of those will be optional additions to the
current code - existing apps can just ignore them.

Avi