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https://issues.apache.org/jira/browse/IO-191?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12666135#action_12666135
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Jukka Zitting commented on IO-191:
----------------------------------
Responding to Sebb's comment first.
{quote}
If one thread creates a new collection whilst another is iterating it, then in
the absence of synchronisation there is no guarantee what state the other
thread will next see for the collection.
{quote}
Not true. For example, consider the following pseudocode where two threads, A
and B, concurrently access the same collection.
{code}
A: iterator = collection.iterator();
A: iterator.next();
B: collection = new Collection();
A: iterator.next();
{code}
A continues to see the contents of the original collection while iterating,
which IMHO is the only reasonable and deterministic behaviour in such cases. If
thread B use collection.clear(), thread A would likely fail with a
ConcurrentModificationException.
However, my objection applies only to cases where the collection is immutable
after initialization (otherwise the threads would in any case need to worry
about synchronization). In AndFileFilter this is not the case, so there I think
using Collection.clear() is actually a valid option. This context is not
visible in the patch, so I'd rather consider such changes on a case-by-case
basis instead of as a part of a bigger changeset generated by an analyzer tool.
> Possible improvements using static analysis.
> --------------------------------------------
>
> Key: IO-191
> URL: https://issues.apache.org/jira/browse/IO-191
> Project: Commons IO
> Issue Type: Improvement
> Reporter: Peter Lawrey
> Priority: Trivial
> Attachments: commons-io-static-analysis.patch
>
> Original Estimate: 3h
> Remaining Estimate: 3h
>
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