[squeak-dev] Re: ProcessWrapperPlugin.dll [was: OSProcess capabilities on Windows]

Andreas wrote:
>Aran Lunzer wrote:
>> Looking at the source code for the DLL, I'm afraid that at the level of my
>> non-Squeak skills it would probably take me a day to rebuild it.  Do you
>> happen to have a 3.7-specific compiled DLL?
>
>It is extremely unlikely that the problem is with the DLL. More likely
>you are switching between VMs that are not compatible with this version.
>Try running your 3.7 images with a more recent VM and see if this works
>with the DLL in question.

Back in my original message about OSProcess I mentioned that I'm working
with a 3.7 Web-browser-plugin VM that has been customised (to do various
things in support of the .NET bridge).  If I can't persuade ProcessWrapper
to work with that, I can't use it.  At least, not this year  :-)

I did a little more testing and, as you suggested, the more recent VM
helped: the out-of-the-box 3.8 release (6665), for example, couldn't load
the ProcessWrapper DLL with its standard VM (Nov 2003), but could when I
wheeled in the VM from 3.9.

So it seems that something has changed in the VMs, and that something in
the DLL only works with new ones.  But given that Balasz said that they
had used ProcessWrapper with 3.7, I wondered whether they had - or could
recompile - a version of the DLL that would be compatible with an old VM.

What has changed in the VM wrt DLL loading?  Something to do with
64/32-bit support, perhaps?


All the best -

Aran

Aran Lunzer wrote:
> So it seems that something has changed in the VMs, and that something in
> the DLL only works with new ones.  But given that Balasz said that they
> had used ProcessWrapper with 3.7, I wondered whether they had - or could
> recompile - a version of the DLL that would be compatible with an old VM.
>
> What has changed in the VM wrt DLL loading?  Something to do with
> 64/32-bit support, perhaps?

I don't recall. But you should be able to recompile the plugin for the
version you need it to work with unless it uses any of the newer
features. There are two ways to do that:

a) Grab the source for the original 3.7 build, put the plugin into the
proper place and build it against the 3.7 sources.

b) Use your current build environment and #define VM_PROXY_MINOR to be
the minimum version you can get away with (i.e., the minimum version the
plugin compiles with).

Both should work.

Cheers,
  - Andreas

Hi There.

I see from this message that you're working in the .NET bridge. I did  
a fair amount of work with this myself a year or two ago as a  
potential means to migrate some of our legacy VB6 stuff via COM  
interop so that we could use Squeak for our new software.

However, I had significant issues with load testing. When I started  
hitting the system with many processes the bridge would  
catastrophically fail due to limitations in the Windows TCP/IP stack:  
I'm sure you're aware that Windows has a built-in limit on the number  
of allowed open Sockets: I would quite easily hit this limit if I  
pushed hard enough, as the architecture of the bridge didn't clean up  
quickly enough for dead Squeak processes (this may really be a  
limitation in Squeak rather than the bridge, but the reliance on TCP/
IP communication between the two effectively means the same thing).

I had planned to try removing the use of sockets entirely and moving  
to something more scalable, but in the end the use case evaporated.

But I'd still love to know if you have progressed the bridge in a way  
that means you no longer get problems like the one I have described  
above. I'd also be willing to share any of the work I did in case it  
might help you, if I can find it.

Regards,
Simon

On 25 Mar 2009, at 03:20, Aran Lunzer wrote:



Consider your responsibility to the environment - think before you print!

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