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https://issues.apache.org/jira/browse/FELIX-4361?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13851543#comment-13851543
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Sander Mak commented on FELIX-4361:
-----------------------------------
One trivial improvement to the patch would be to allocate an ArrayList of the
correct capacity, to avoid resizing overhead:
> List copyComponents = new ArrayList(m_components.size());
or even let the list copy itself without for loop in the synchronized block
> List copyComponents = new ArrayList(m_components);
> Possible ConcurrentModificationException in DependencyManager.getComponents()
> -----------------------------------------------------------------------------
>
> Key: FELIX-4361
> URL: https://issues.apache.org/jira/browse/FELIX-4361
> Project: Felix
> Issue Type: Bug
> Components: Dependency Manager
> Affects Versions: dependencymanager-3.1.0
> Reporter: Paul Bakker
> Assignee: Marcel Offermans
> Attachments: FELIX-4361.patch
>
>
> DependencyManager.getComponents() returns a unmodifiableList created as
> follows:
> {code}
> Collections.unmodifiableList(m_components);
> {code}
> However, this does not provide safe iteration on the result of calling this
> method. E.g. the following can fail with a ConcurrentModificationException:
> {code}
> List<ComponentDeclaration> components = dm.getComponents();
> for (ComponentDeclaration c : components) {
> //do something
> }
> {code}
> This is possible because the underlaying collection can be modified during
> iteration. Wrapping it in an unmodifiable list doesn't prevent this, because
> the modifications are done on the original list.
> This can be fixed by copying the list to a new collection before returning.
> This is more expensive, but the only way to be safe.
> Patch and test provided.
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