RFR: 8252971: WindowsFileAttributes does not know about Unix domain sockets [v4]

[Michael McMahon]

On Mon, 8 Feb 2021 16:48:44 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> Michael McMahon has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 11 additional commits since the last revision:
>> 
>>  - Merge branch 'master' into 8252971-socket-attributes
>>  - add specific check for unix domain socket
>>  - Merge branch 'master' into 8252971-socket-attributes
>>  - update
>>  - update
>>  - update
>>  - update
>>  - update after Alan's first review
>>  - Merge branch 'master' into 8252971-socket-attributes
>>  - test update
>>  - ... and 1 more: https://git.openjdk.java.net/jdk/compare/6a98ca22...746b4762
>
> src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java line 346:
> 
>> 344:                                 Set.of(WindowsChannelFactory.OPEN_REPARSE_POINT),
>> 345:                                 0L);
>> 346:                     fc.close();
> 
> The new version looks a bit strange. As I read it, the attempt to open the file fails with ERROR_CANT_ACCESS_FILE so you then check test if the file is a socket file. That succeeds so we should be done. What is the reason for opening the file again?

I added the test of the socket reparse tag to be 100% sure that we weren't returning false positives for other cases of ERROR_CANT_ACCESS_FILE. But, otherwise, I thought I had to open the file the same way as before to be sure that it is readable. If checking the reparse tag is sufficient then great, that simplifies the change.

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PR: https://git.openjdk.java.net/jdk/pull/2424