RFR: 8316304: (fs) Add support for BasicFileAttributes.creationTime() for Linux [v11]

[Severin Gehwolf]

On Mon, 9 Oct 2023 18:33:41 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> Severin Gehwolf has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - Keep wrapper function signature compatible to statx
>>  - Refactor test so as to use Linker from JEP 454.
>>    
>>    @enablePreview still needed as of yet. This can go once
>>    JDK-8312522 integrates.
>
> test/jdk/java/nio/file/attribute/BasicFileAttributeView/CreationTime.java line 30:
> 
>> 28:  * @library  ../.. /test/lib
>> 29:  * @build jdk.test.lib.Platform
>> 30:  * @enablePreview
> 
> It doesn't matter but I think the convention is to put `@enablePreview` before `@library` and `@build`.

This shouldn't matter indeed as I intend to push only once #15103 is pushed not needing the `@enablePreview` annotation.

> test/jdk/java/nio/file/attribute/BasicFileAttributeView/CreationTime.java line 96:
> 
>> 94:             // Creation time read depends on statx system call support
>> 95:             supportsCreationTimeRead = Linker.nativeLinker().defaultLookup().find("statx").isPresent();
>> 96:             System.out.println("[Linux] Debug: supportsCreationTimeRead == " + supportsCreationTimeRead);
> 
> I think you left a debug statement here, or if you didn't then maybe drop the work "Debug" as it looks out of place here.

I can drop the `Debug` word, but would like to keep the rest as the test behaves differently whether or not `supportsCreationTimeRead` is true or not. On a `statx`-supporting system it would check that the modified time is different from the creation time. Otherwise it wouldn't. So it's nice to know which mode the test ran in.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15792#discussion_r1351848302
PR Review Comment: https://git.openjdk.org/jdk/pull/15792#discussion_r1351843932