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https://issues.apache.org/jira/browse/FELIX-3422?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14052422#comment-14052422
]
Denis Rossi commented on FELIX-3422:
------------------------------------
I found that LocalRepositoryImpl is registering itself as AllServiceListener.
In the serviceChanged method the m_snapshotTimeStamp, that is used by
getLastModified() method, is updated and the bundle is removed and re-added:
public void serviceChanged(ServiceEvent event)
{
Bundle bundle = event.getServiceReference().getBundle();
if (bundle.getState() == Bundle.ACTIVE && event.getType() !=
ServiceEvent.MODIFIED)
{
synchronized (this)
{
removeBundle(bundle, m_logger);
addBundle(bundle, m_logger);
m_snapshotTimeStamp = System.currentTimeMillis();
}
}
}
> Improve framework state change checking in ResolverImpl.deploy()
> ----------------------------------------------------------------
>
> Key: FELIX-3422
> URL: https://issues.apache.org/jira/browse/FELIX-3422
> Project: Felix
> Issue Type: Improvement
> Components: Bundle Repository (OBR)
> Affects Versions: bundlerepository-1.6.6
> Environment: All platforms
> Reporter: Declan Cox
> Priority: Minor
> Labels: patch
>
> Currently the ResolverImpl deploy method checks to see if the last modified
> time of a repository instance is greater than the last updated resolution
> start timestamp, indicating a possible inconsistent state between the
> repository resources and the set of resolved resources. However it appears
> that the last modified time on a repository instance can be updated by the
> framework without it affecting the resolve state of the contained resources.
> The following comment indicates that the original implementer is aware of
> this, viz:
> // Check to make sure that our local state cache is up-to-date
> // and error if it is not. This is not completely safe, because
> // the state can still change during the operation, but we will
> // be optimistic. This could also be made smarter so that it checks
> // to see if the local state changes overlap with the resolver.
> for (int repoIdx = 0; (m_repositories != null) && (repoIdx <
> m_repositories.length); repoIdx++)
> {
> if (m_repositories[repoIdx].getLastModified() >
> m_resolveTimeStamp)
> {
> throw new IllegalStateException("Framework state has changed,
> must resolve again.");
> }
> }
> I have encountered this error on an upgrade from version 1.0.3 to 1.6.6
> recently (we have a provisioning agent which delegates to the bundle
> repository ). What we have seen is that between a call to resolve() and
> deploy() the local repository last modified timestamp is updated, however on
> investigation all contained resources have been resolved but we get the
> IllegalStateException nonetheless.
> We are not sure why this update happens and where it comes from (this we will
> investigate further), however we could avoid the unnecessary exception by
> checking the overlap with the resolved set as suggested above.
> To this end I added the following private method to ResolverImpl in a local
> copy, which seems to do the trick:
> /**
> * Check to see if the repository state has changed and whether
> * this state change requires re-resolving
> *
> * @param repository - repository instance
> * @return true if state has changed requiring re-resolving, otherwise
> false
> */
> private boolean hasStateChanged(final Repository repository) {
> if (repository.getLastModified() > m_resolveTimeStamp.get()) {
> // check overlap with resolver
> final Resource[] resources = repository.getResources();
> for (int i = 0; i < resources.length; i++) {
> if (!m_resolveSet.contains(resources[i])) {
> return true;
> }
> }
> }
> return false;
> }
> The corresponding change to the deploy method is as follows:
> // Check to make sure that our local state cache is up-to-date
> // and error if it is not. This is not completely safe, because
> // the state can still change during the operation, but we will
> // be optimistic. This could also be made smarter so that it checks
> // to see if the local state changes overlap with the resolver.
> for (int repoIdx = 0; (m_repositories != null) && (repoIdx <
> m_repositories.length); repoIdx++)
> {
> final Repository repository = m_repositories[repoIdx];
> if (hasStateChanged(repository))
> {
> throw new IllegalStateException("Framework state has changed,
> must resolve again.");
> }
> }
> I am not sure if this is the most efficient way to do this and if all
> considerations about state change have been taken into account (I am new to
> Felix) but I thought would submit it for consideration as a potential patch.
> Thanks,
> Declan
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