The GRE and you.

[Doug Turner]

This includes an overview of some of the work that Chak, ssu, curt, and
I have been doing. I wanted to get some feedback about both the general
direction and actual implementation. This work is regarding the Gecko
Runtime Environment. In the not so near future, there will be GRE's
sitting on endusers machines. In fact, you can download a GRE from
ftp.mozilla.org today. I would like to start letting the mozilla client
start using the GRE if it is installed and eventually install the GRE
with the mozilla client.

Before doing all of this there are few parts to this discussion that I
would like feedback for.

First I would like feedback on how we are going to find a GRE? (Note
that this is just the default behavior. Embedders can code up anything
they like – they can choose to use a private copy of the GRE shared only
between ‘their’ gecko applications or they can choose a different search
order, ect.) The basic idea is an embedding application starts up, it
looks around for where the GRE is, then it sets up its load library
paths, finally it dynamically loads XPCOM. From this point, everything
else that embedders have been doing is exactly the same.

Currently, on windows, we store where a GRE is installed in the windows
registry file. On nix, I have a patch with will store the equivalent
information in /etc/gre.conf (if you have other places I should check,
please let me know). So that a user can run against a local GRE, I was
thinking about offering a $(HOME)/.gre.config file which would be
checked first. The windows work (as well as a broad description of the
GRE) is described here:

http://www.mozilla.org/projects/embedding/MRE.html

I wrapped up all of the necessary loading logic into a library so that
it is easy for embedders to actually startup Gecko. This bug describes
(in code) exactly what the format of the gre.conf file is. The format
is really simple and extensible. This work is being done here:

http://bugzilla.mozilla.org/show_bug.cgi?id=185681

The next idea that I wanted discussed was converting the mozilla
application (and also, viewer and other embedding applications) to use
the MRE if present. What I am going to do is make the mozilla app use
the default startup code I mentioned above. I have prototyped this
work, and for the most part everything seams to work fine. When
everything is nailed down, I will post a patch to his bug:

http://bugzilla.mozilla.org/show_bug.cgi?id=173262

I would like to also change some of the testing tools. Specifically, I
am going to make regxpcom a lot better. It will no longer be tied to a
release, ie you will be able to have a copy of regxpcom in your bin/
directory if you wanted. This work is here:

http://bugzilla.mozilla.org/show_bug.cgi?id=183075

The next thing is how the GRE is built and delievered. I have asked
Chris Seawood to add explicit supported for the GRE in the makefiles.
This is similar to what we did to support the SDK exports. Basically,
there will not be a separate packaging step to bundle the GRE. It will
be built in mozilla/dist/gre. For the time being, files will be
mirrored into dist/bin. However, at some point in the future, I would
like to see dist/bin going away and instead a mozilla/dist/<app>, where
app is the directory that contains the current application your
building. This may be phoenix, the mozilla client, ect. (Details
haven’t be worked out for how this is going to work, but the general
direction is that you pull or build the GRE and then build an
application on top of it.) The work that Chris is doing is being
tracked here:

http://bugzilla.mozilla.org/show_bug.cgi?id=186241


Please send me feedback directly or comment in the bugs.


Thanks,

Doug Turner
***@netscape.com