[HARMONY-6236] [classlib][luni] ArrayList breaks when given concurrent collections as input

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.0M10
• Fix Version/s: 5.0M11
• Component/s: Classlib
• Environment: SVN Revision: 784898
• Patch Info: Patch Available
• Estimated Complexity: Advanced
• Assignee: Tim Ellison
• Reporter: Jesse Wilson
• Created: 15/Jun/09 22:26
• Updated: 30/Nov/10 16:47
• Resolved: 16/Jun/09 09:20

Description

new ArrayList() and ArrayList.addAll(Collection) assume the passed-in collection will not change between calls.

In the attached test case, a special collection simulates a background thread calling "remove" after the ArrayList has called size(), but before it has called "toArray()". This causes the collection to return a null-padded array, which leads to a corrupt ArrayList. The attached patch fixes the problem.

Issue Links

• is broken by: HARMONY-6681 AbstractCollection.toArray() and AbstractCollection.toArray(T[]) are broken for concurrently modified collections like ConcurrentHashMap.keySet()