A correction. I only get this problem when I do "bin\karaf.bat" NOT when I do a clean start "bin\karaf.bat clean".
I also did some more logging and the sequence of events seem to be: - accept: intercepted - configurationChanged - Invalidating mathing... - accept: intercepted - Invalidating selected... - Done invalidating - Validated - getServiceReferences - Invalidated Thus, it seems like the instance becomes intermittently valid before the first call to my interceptor's "getServiceReferences". I guess this is entirely possible. The intention with requiring the "intercepted=true" on my dependenies was to make sure that the instance does not become valid before my interceptor has a chance to intercept it. However, since the accept() method is called before the getServiceReferences method it still becomes intermittently valid. My dependency look like this: @Requires(optional = false, id = "extenders", filter = "(intercepted=true)") private IRouteExtender[] mExtenders; In this case there are services available that implement the IRouteExtender interface so when my accept method sets interface=true on the dependency it immediately becomes resolved. Then when I get to my "getServiceReferences" method I re-calculate the the dependencies and note that none of the services implementing the IRouteExtender interfaces is allowed to match (because they have the wrong service properties) I will return an empty set of matching services and the instance will become invalid. Not sure how to solve this with interceptors. I would prefer if the instance could not become valid until both the accept() and the getServiceReferences() methods were called. Until then my interceptor hasn't fully been allowed to do its job. /Bengt Thus /Bengt 2014-02-21 14:15 GMT+01:00 Bengt Rodehav <[email protected]>: > Hello Clement, > > Some comments inline below. > > /Bengt > > > > 2014-02-21 12:53 GMT+01:00 Clement Escoffier <[email protected]> > : > >> Hi, >> >> >> On 20 févr. 2014, at 13:22, Bengt Rodehav <[email protected]> wrote: >> >> > This is a follow up on another discussion I had with Clement on this >> > mailing list: >> > >> > >> http://apache-felix.18485.x6.nabble.com/Using-iPojo-interceptors-tt5006168.html#a5006276 >> > >> > I'm now trying to get the interceptor solution into production. >> > >> > Remember that I have to invalidate my instances when their >> configuration is >> > changed. This is because I need to re-evalutate the dependencies for the >> > instance. >> > >> > Originally, I only called the invalidateSelectedServices() method on the >> > DependencyModel. This worked mostly but not when starting a fresh >> container >> > (I use Karaf and start it with "bin\karaf.bat clean"). My instance then >> > first becomes valid but then becomes invalid. I think this is because of >> > the ordering. The accept() method had not been called prior to >> > the getServiceReferences() method. The dependency is therefore not set >> to >> > "intercepted=true" which makes it invalid. >> >> the filter is updated by the interceptor. (just want to be sure I >> understand). In that case, if the interceptor arrives after the instance >> creation, the filter will be set when the interceptor arrives. >> > > Yes, my interceptor sets intercepted to true on the dependency which makes > sure that the filter match. > > > >> >> > >> > Replacing the call to invalidateSelectedServices() with a call to >> > invalidateMatchingServices() seems to do the trick. However, there is >> one >> > small glitch that I would like to fix. >> > >> > If I have a configuration that should not be valid (e g I specified an >> > extender id that is not present) the instance should never be valid. >> But, >> > when starting Karaf (both with "bin\karaf.bat" and "bin\karaf.bat >> clean"), >> > the instance becomes valid before it becomes invalid. It does end up in >> the >> > right state (invalid in this case) but for a short period of time it is >> > valid which will cause a lot of things to happen in my code that then >> must >> > be reversed when it becomes invalid. >> > >> > I logged the sequence of events and it seems that the accept() method is >> > called first. I will then set "intercepted=true". This immediately makes >> > the instance valid. Shortly thereafter getServiceReferences() is >> called. I >> > will then re-calculate the dependency requirements and when I later >> > invalidate the dependencies the instance will become valid. >> > >> > So, there is a short time frame where the instance is valid although it >> > shouldn't be. How can I fix that? >> >> This looks like a bug, as the dependency can be valid only if the set of >> selected services is not empty. From what you say, it looks like the >> dependency is valid because the set of matching services is not empty. >> > > Is there anything I can do to investigate this? Is it possible for you to > take a look if there is indeed a "gap" where this can happen? > > I think that things are a little complicated since I also listen on > configuration changes. I need to recalculate the matching services when the > configuration of the intercepted instance changes. When starting the > container (Karaf), I get more than one configuration change and thus the > dependencies are invalidated more than once. What if the sequence were: > > 1. Configuration change causing the dependencies to become invalidated > 2. Accept. Will set intercepted to true > 3. getServiceReferences which will calculate the required dependencies > 4. Configuration change again causing the dependencies to become > invalidated > 5. Accept. Will set intercepted to true > 6. getServiceReferences which will calculate the required dependencies > > Not sure if there is any point in which an instance could become valid > when it shouldn't. > > I will also try to see if the problem could be the configuration admin. I > use file install for my configuration. I have a feeling that the first > configuration being pushed is a default configuration and not the one from > the configuration file. Then that might explain it. > > >> > >> > From my point of view this is similar to a transaction. I do not want >> the >> > instance to become valid before I have done all my "intercepting" which >> is >> > after BOTH the accept() method AND the getServiceReferences() method >> have >> > been called. >> >> In theory, it is how it should work... >> >> > >> > BTW I also noted that the "dependencies" member in >> > the DefaultDependencyInterceptor class (I extend the >> > DefaultServiceRankingInterceptor class) seems to contain duplicates of >> my >> > dependency. The same DependencyModel instance occurs twice in the List. >> > Seems like a bug to me. Perhaps the List should be a Set? >> >> Definitely, could you open an issue ? >> >> Clement >> >> > >> > /Bengt >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> >> >
