Hi Martin,

Just a purely theoretical question...

On 08/08/2017 02:06 AM, Martin Buchholz wrote:
Need to fix

    1. JDK-8185830 <https://bugs.openjdk.java.net/browse/JDK-8185830>

ConcurrentSkipListSet.clone() fails with UnsupportedOperationException

(It would be nice if we could submit a jdk9 backport now instead of waiting)

Regarding ConcurrentSkipListSet.clone()... The 'm' field is final presumably to allow "safe" publication of ConcurrentSkipListSet objects to other threads via data races.

clone() O.T.O.H. uses Field.setAccessible(true) on a final field, followed with Field.set(), which amounts to Unsafe.putObjectVolatile(). Is this equivalent to volatile write? Is it possible for a normal write of a reference to a cloned ConcurrentSkipListSet (i.e. publication via data race) to bubble up before the volatile write of 'm' field inside the clone and consequently allow an observer of a reference to the clone to modify the backing map of the original ConcurrentSkipListSet?

Regards, Peter

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