RFR of JDk9 8164623: Doc typo in java/util/concurrent/ConcurrentLinkedDeque.java and ConcurrentLinkedQueue.java
huaming.li at oracle.com
Wed Aug 24 02:04:33 UTC 2016
On 2016/8/24 9:22, David Holmes wrote:
> Hi Hamlin,
> On 23/08/2016 10:53 PM, Hamlin Li wrote:
>> On 2016/8/23 17:10, David Holmes wrote:
>>> Hi Hamlin,
>>> On 23/08/2016 6:55 PM, Hamlin Li wrote:
>>>> Below doc is not correct, because for ConcurrentLinkedDeque and
>>>> ConcurrentLinkedQueue, addAll is a atomic operation.
>>> No it is not! There is no bug here. Are you perhaps confusing
>>> thread-safe with atomic?
>> Hi David,
>> Thank you for review. Please let me clarify.
>> Although "public boolean addAll(Collection<? extends E> c)" is not
>> protected by any lock or monitor, the implementation in both
>> ConcurrentLinked*eque.java still "Atomically append the chain at the
>> tail of this collection", so I still think addAll is a atomic method.
> Yes you are correct, my apologies.
It's OK :-) I should have made it more clear in code review request.
> But as Martin states this is an implementation artifact not something
> that the specification wants to be guaranteeing.
Yes, I think Martin's suggestion is more reasonable.
Thank you both!
>> Even though it's not called atomic at this situation, the statement "For
>> example, an iterator operating concurrently with an addAll operation
>> might view only some of the added elements." is wrong, because either
>> all objects in Collection c are viewed by iterator, or none of objects
>> in Collection c are viewed by iterator.
>> Thank you
>>>> "Additionally, the bulk operations addAll, removeAll, retainAll,
>>>> containsAll, equals, and toArray are not guaranteed to be performed
>>>> atomically. For example, an iterator operating concurrently with an
>>>> addAll operation might view only some of the added elements."
>>>> It should be modified as some thing like below:
>>>> "Additionally, the bulk operations removeAll, retainAll, containsAll,
>>>> equals, and toArray are not guaranteed to be performed atomically."
>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8164623
>>>> webrev: http://cr.openjdk.java.net/~mli/8164623/webrev.00/
>>>> Thank you
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