On Tue, May 22, 2012 at 9:16 AM, Siano, Stephan <stephan.si...@sap.com> wrote: > I actually do not understand your argument. The class space compatibility > mentioned in 121.3.1 of the compendium spec is actually fulfilled better if > the blueprint apis are imported and exported by the extender bundle. In this > case the class loader of the extender and the class loader of the blueprint > bundle actually reference to the same class, whereas if the packages are not > imported but only exported by the extender bundle this class space > compatibility will break as soon as the blueprint bundle is wired with any > other bundle exporting the api is present.
Section 121.3.1 did not make any explicit references to multiple extenders because there was an RFC going on at that time to address this issue, but that was the main use case for writing such a section. The spec also says that blueprint bundles should import the blueprint package (which does not make sense on its own unless the package is actually needed), and that's for the same reason. Your problem is due to the fact that you deploy compendium. That's a really bad thing to do anyway as it breaks the modularity of all osgi services implementations. You can always use the fine grained bundles if you prefer and that will solve your problem. > Sure: with your model you can have two different blueprint extender bundles > active at the at the same time and the blueprint bundle is extended by > whichever blueprint bundle it is wired to (if both implement the same > blueprint version this is random usually depending on the start order of the > bundles), but I actually do not really see a use case for that. That's really the use case that we had in mind when the spec was discussed and written. For example, karaf rely on Aries Blueprint (because of the namespace handlers), but some users want to be able to deploy spring-dm (to leverage some spring specific features). The only way to handle such a use case is to really split the class space. > > Why would you need additional bundles to deploy? Importing a bundle you do > also provide does not require you to have another bundle present that exports > the packages, it just means that you don't have these class space > compatibility issues if another bundle is present that is exporting the same > API (e.g. and API bundle containing the compendium or enterprise APIs). This is a *bug fix* release. So you should be able to upgrade blueprint-bundle should work. Forcing an import is a no go. > > -----Original Message----- > From: Guillaume Nodet [mailto:gno...@gmail.com] > Sent: Dienstag, 22. Mai 2012 08:42 > To: dev@aries.apache.org > Subject: Re: svn commit: r1340184 - > /aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml > > The rule you mentioned is the general rule, and I agree with it in > most of the cases for API packages. > However, as I mentioned, for blueprint, things are a bit different. > You can see that by checking 121.3.1 which specifically talks about > class space compatibility, and there's a reason for that as I > explained (I can go though it with more details if necessary). The > overall goal is to actually split the class space into separate > portions. > > So first, that's would be incompatible with 0.3 because it would needs > an additional bundle to deploy (that will the case in 1.0 anyway with > the small bundles, so please can we try to at least keep one version > clean ?). > Second, it would lead to serious problems when trying to have multiple > blueprint extenders in the same container, which is supposed to work > to some degree. > And last, the only benefit of sharing API is that you should be able > to update the extender without having to refresh the blueprint > bundles. However, in real cases, that's rarely the case and the all > the blueprint beans have to be recreated anyway, so the benefit is > very low. > > On Tue, May 22, 2012 at 7:52 AM, Siano, Stephan <stephan.si...@sap.com> wrote: >> >> AFAIK the OSGi spec proposes to do the import and export in such cases >> (section 3.5.6 of the 4.3 core spec). Personally I find it much more >> probable that the compendium or enterprise bundles are present, than having >> two different blueprint implementations on the same stack. I also do not see >> any issues with the different blueprint implementation importing the same >> org.osgi.blueprint APIs. They are specified in the spec and should always be >> the same wherever they come from. >> >> So I essentially do think that it's a good idea to import the osgi api. >> >> -----Original Message----- >> From: Guillaume Nodet [mailto:gno...@gmail.com] >> Sent: Dienstag, 22. Mai 2012 00:44 >> To: dev@aries.apache.org >> Subject: Re: svn commit: r1340184 - >> /aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml >> >> I don't think that's a good idea to import the osgi api. >> >> It may lead to problems if multiple blueprint implementations are >> deployed for some reason. >> To support such a case, the blueprint bundles are supposed to import >> the org.osgi.blueprint package iirc, so that the osgi framework wiring >> will be correctly split and only the blueprint extender which has been >> imported will actually extend the bundle. By importing the api, two >> extenders can then be compatible and both would extend the bundle. >> >> IF the main reason is that people have the compendium bundle deployed, >> well, that's a bad idea because the same problem also tend to apply >> with other osgi services such as ConfigAdmin and others which usually >> ship their own version of the package. >> >> >> On Fri, May 18, 2012 at 7:42 PM, <dk...@apache.org> wrote: >>> Author: dkulp >>> Date: Fri May 18 17:42:46 2012 >>> New Revision: 1340184 >>> >>> URL: http://svn.apache.org/viewvc?rev=1340184&view=rev >>> Log: >>> Import the osgi blueprint stuff so it can work with a wider range of >>> containers >>> >>> Modified: >>> aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml >>> >>> Modified: aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml >>> URL: >>> http://svn.apache.org/viewvc/aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml?rev=1340184&r1=1340183&r2=1340184&view=diff >>> ============================================================================== >>> --- aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml (original) >>> +++ aries/branches/blueprint-0.3.2-fixes/blueprint-bundle/pom.xml Fri May >>> 18 17:42:46 2012 >>> @@ -40,7 +40,6 @@ >>> </aries.osgi.activator> >>> <aries.osgi.import> >>> !org.apache.aries.blueprint*, >>> - !org.osgi.service.blueprint*, >>> org.eclipse.osgi.internal.loader;resolution:=optional, >>> org.eclipse.osgi.framework.internal.core;resolution:=optional, >>> org.eclipse.osgi.framework.adaptor;resolution:=optional, >>> >>> >> >> >> >> -- >> ------------------------ >> Guillaume Nodet >> ------------------------ >> Blog: http://gnodet.blogspot.com/ >> ------------------------ >> FuseSource, Integration everywhere >> http://fusesource.com > > > > -- > ------------------------ > Guillaume Nodet > ------------------------ > Blog: http://gnodet.blogspot.com/ > ------------------------ > FuseSource, Integration everywhere > http://fusesource.com -- ------------------------ Guillaume Nodet ------------------------ Blog: http://gnodet.blogspot.com/ ------------------------ FuseSource, Integration everywhere http://fusesource.com
