RFR: 8245194: Unix domain socket channel implementation [v3]

[Michael McMahon]

> Continuing this review as a PR on github with the comments below incorporated. I expect there will be a few more
> iterations before integrating.
> On 06/09/2020 19:47, Alan Bateman wrote:
>> On 26/08/2020 15:24, Michael McMahon wrote:
>>>
>>> As I mentioned the other day, I wasn't able to use the suggested method on Windows which returns an absolute path. So,
>>> I added a method to WindowsPath which returns the path in the expected UTF-8 encoding as a byte[]. Let me know what you
>>> think of that.
>>>
>>> There is a fair bit of other refactoring and simplification done also. Next version is at:
>>>
>>> http://cr.openjdk.java.net/~michaelm/8245194/impl.webrev/webrev.9/
>>>
>> Adding a method to WindowsPath to encode the path using UTF-8 is okay but I don't think we should be caching it as the
>> encoding for sun_path is an outlier on Windows. I'm also a bit dubious about encoding a relative path when the resolved
>> path (before encoding) is > 247 chars. The documentation on the MS site isn't very completely and I think there are a
>> number points that require clarification to fully understand how this will work with relative, directly relative and
>> drive relative paths.
>>
> 
> Maybe it would be better to just use the path returned from toString() and do the conversion to UTF-8 externally. That
> would leave WindowsPath unchanged.
>> In the same area, the new PathUtil is a bit inconsistent with the existing provider code. One suggestion is to add a
>> method to AbstractFileSystemProvider instead. That is the base class the platform providers and would be a better place
>> to get the file path in bytes.
>>
> 
> Okay, I gave the method a name that is specific to Unix domain sockets because this UTF-8 strangeness is not likely to
> be useful by other components.
>> One other comment on the changes to the file system provider it should be okay to change UnixUserPrinipals ad its
>> fromUid and fromGid method to be public. This would mean that the patch shouldn't need to add UnixUserGroup (the main
>> issue is that class is that it means we end up with two classes with static factory methods doing the same thing).
> 
> Okay, that does simplify it a bit.
> 
> Thanks,
> Michael.
> 
>> -Alan.
>>
>>
>>
>>
>>
>>

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 four additional commits since
the last revision:

 - Merge branch 'master' into unixdomainchannels
 - Made some changes relating to selection of the local directory where automatically
   bound server sockets are created. After this change it is no longer necessary
   to specify the location in individual tests.
 - unixdomainchannels: fixing compile error on Windows and Alan's review comment this morning
 - unixdomainchannels: initial commit from hg sandbox with changes from Alan's email 06/09/2020

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/52/files
  - new: https://git.openjdk.java.net/jdk/pull/52/files/4d08c15a..110b45c0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=52&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=52&range=01-02

  Stats: 13647 lines in 426 files changed: 7255 ins; 4331 del; 2061 mod
  Patch: https://git.openjdk.java.net/jdk/pull/52.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/52/head:pull/52

PR: https://git.openjdk.java.net/jdk/pull/52