RFR: 8310902: (fc) FileChannel.transferXXX async close and interrupt issues [v4]

[Brian Burkhalter]

On Wed, 28 Jun 2023 19:46:13 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> This change fixes a number of bugs with FileChannel.transferTo/transerFrom that arise when the source or target channel is closed, or the thread is interrupted, during the transfer. More specifically:
>> 
>> - The direct implementations operate on the raw file descriptor and don't prevent the target/source channel from being closed during the transfer. For this PR, the direct transferTo is limited to cases where the target is a FileChannel or SocketChannel. It could be extended to other SelChImpl implementations (SinkChannel, DatagramChannel) if needed, but they are less interesting at this time.
>> 
>> - The transferTo/transferFrom methods are specified to throw ClosedByInterruptException after closing both channels. This is implemented inconsistently, and leaves one channel open in several cases.
>
> Alan Bateman has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Cleanup transferToDirectNotSupported/transferFromDirectNotSupported setting

Last changes look good. Approved.

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Marked as reviewed by bpb (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/14656#pullrequestreview-1504322865