Pawe�� Boguski created SLING-11754:
--------------------------------------
Summary: Race condition in OsgiInstaller
Key: SLING-11754
URL: https://issues.apache.org/jira/browse/SLING-11754
Project: Sling
Issue Type: Bug
Components: Installer
Affects Versions: Installer Core 3.12.0, Installer Packages Factory 1.0.4
Reporter: Pawe�� Boguski
[OsgiInstallerImpl|https://github.com/apache/sling-org-apache-sling-installer-core/blob/master/src/main/java/org/apache/sling/installer/core/impl/OsgiInstallerImpl.java#L143]
is using
[SortingServiceTracker|https://github.com/apache/sling-org-apache-sling-installer-core/blob/master/src/main/java/org/apache/sling/installer/core/impl/SortingServiceTracker.java#L87]
to schedule a retry of the OSGi installer run when new service of type
ResourceTransformer is added. During the OSGi installer run, the list of
available ResourceTransformer services is loaded to [transform
resources|https://github.com/apache/sling-org-apache-sling-installer-core/blob/master/src/main/java/org/apache/sling/installer/core/impl/OsgiInstallerImpl.java#L953].
It might happen that the list of available ResourceTransformer services will be
loaded during transforming resources before the new ResourceTransformer which
triggered the OSGi installer run will be available in the SortingServiceTracker
instance, because the scheduleRetry call is done in
SortingServiceTracker.addingService not when the service is already available
in SortingServiceTracker but during the preparation of the service instance
(the instance returned from SortingServiceTracker.addingService is later added
to services list in SortingServiceTracker).
So in other words, there is a race condition between adding a new service
instance to SortingServiceTracker services list and OSGi installer run which
perform getting the instances of ResourceTransformer services from the
SortingServiceTracker.
In the result activation of ResourceTransformer might trigger the OSGi
installer run but the service will not be found during the run.
Example issue caused by this:
If such a last OSGi installer run would be caused by activation of
[PackageTransformer|https://github.com/apache/sling-org-apache-sling-installer-core/blob/master/src/main/java/org/apache/sling/installer/core/impl/OsgiInstallerImpl.java#L953]
the untransformed content packages (for example added by OSGI feature model
during the first start of the instance) stays untransformed.
In our pipelines for PRs validation this is happening very often.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
