[JENKINS-41037] Unable to serialize lists because of ConcurrentModificationException

This keeps up reported as Flaked tests as it seems to clash with some other test (related activity) and gets retried correctly. (Using synchronized mocks makes no difference).

Reproducible by https://github.com/jenkinsci/resource-disposer-plugin/commit/bc5f00008cc31a680e103dd7bd804bd64b0a4668 and mvn clean package. Not by mvn clean package -Dtest=AsyncResourceDisposerTest#combined of course.

```
Caused by: java.util.ConcurrentModificationException
at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:953)
at java.util.LinkedList$ListItr.next(LinkedList.java:886)
at com.thoughtworks.xstream.converters.collections.CollectionConverter.marshal(CollectionConverter.java:73)
at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:84)
at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:223)
at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:210)
... 128 more

```

---
Originally reported by olivergondza, imported from: Unable to serialize lists because of ConcurrentModificationException

• status: In Progress
  
• priority: Minor
  
• component(s): cloud-stats-plugin
  
• label(s): xstream
  
• resolution: Unresolved
  
• votes: 4
  
• watchers: 12
  
• imported: 20251216-182730
  

Raw content of original issue

This keeps up reported as Flaked tests as it seems to clash with some other test (related activity) and gets retried correctly. (Using synchronized mocks makes no difference).


Reproducible by https://github.com/jenkinsci/resource-disposer-plugin/commit/bc5f00008cc31a680e103dd7bd804bd64b0a4668 and mvn clean package. Not by mvn clean package -Dtest=AsyncResourceDisposerTest#combined of course.




Caused by: java.util.ConcurrentModificationException

	at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:953)

	at java.util.LinkedList$ListItr.next(LinkedList.java:886)

	at com.thoughtworks.xstream.converters.collections.CollectionConverter.marshal(CollectionConverter.java:73)

	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)

	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)

	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:84)

	at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:223)

	at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:210)

	... 128 more

Start by checking commit bc5f00008cc31a680e103dd7bd804bd64b0a4668 and reproducing the failure with mvn clean package, then compare it with AsyncResourceDisposerTest#combined. Trace the ConcurrentModificationException through XStream's CollectionConverter and Jenkins' RobustReflectionConverter; done means the full package run no longer produces this serialization failure.

Written by the indexing model from the issue text.