Hi,
Guillaume Nodet schrieb:
> Let's say we have two bundles
>
> foo-1.0:
> Export-Package: a;version="1.0"
> Import-Package: a;version="1.0"
>
> foo-2.0:
> Export-Package: a;version="2.0"
> Import-Package: a;version="2.0"
>
> In felix (trunk), if you install foo-2.0, then foo-1.0, you end up with:
>
> foo-2.0:
> Export-Package: a;version="2.0"
>
> foo-1.0:
> Import-Package: a;version="2.0"
This is correct as the resolution specification in Section 3.7,
Resolution of the core spec (right at the end of that section):
The following list defines the preferences, if multiple choices are
possible,
in order of decreasing priority:
* A resolved exporter must be preferred over an unresolved exporter.
* An exporter with a higher version is preferred over an exporter with
a lower version.
* An exporter with a lower bundle ID is preferred over a bundle with a
higher ID.
This, since foo-2.0 exports a more recent version, both should import
that version.
To prvent foo-1.0 from importing a;version="2.0" the import would have
to be written as a version range excluding version 2.0:
Import-Package: a;version="[1.0,2.0)"
This would effectively result in foo-1.0 and foo-2.0 using incompatible
classes and not be able to exchange objects from the "a" package.
(But you might want to have this ...)
There is catch, tough: Consider foo-1.0 installed and started. Now you
install and start foo-2.0. Now, foo-1.0 is wired to its own export and
foo-2.0 is wired to its own export and thus both bundles do *not* share
the a package.... If you then refresh foo-1.0 (with above import
declaration) it will wire to foo-2.0's export.... [You might call this a
corner case, but I am currently fighting such a case looking for a
solution].
Regards
Felix
>
> This really looks ackward (and will mostly lead to failures if the
> major versions are not really compatible), though I haven't seen
> anything in the core spec to forbid this.
> Section 3.7 says that the resolution for foo-1.0 should either choose
> an external package (which is what done here) or an internal package.
>
> Equinox seems to handle it using an internal package.
>
> What would you think about changing the resolution algorithm so that
> it try to use an internal package instead of an external package if
> all the constraints are met ?
>
>
>
>
>
