RFR: 8285515: (dc) DatagramChannel.disconnect fails with "Invalid argument" on macOS 12.4 beta2 [v4]

[Alan Bateman]

On Thu, 28 Apr 2022 12:52:37 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> Can I please get a review of this change with proposes to address the issue reported in https://bugs.openjdk.java.net/browse/JDK-8285515?
>> 
>> We have noticed that in the latest 12.4 Beta2 version of MacOSX, the implementation of `DatagramChannelImpl.disconnect` fails with an unexpected error. 
>> 
>> Internally, the disconnect is implemented as a call to `connect` by passing it a "null" address as suggested in the documentation of `man connect`. In previous versions of MacOSX, this call used to return a `EADDRNOTAVAIL` errno and at the same time would correctly dissolve the connected association. The `EADDRNOTAVAIL` was then caught and intentionally ignored by the code in the JNI layer in `DatagramChannelImpl.disconnect0`.
>> 
>> In MacOSX 12.4 Beta 2 we are now seeing this `connect` call return `EINVAL`. This change in behaviour is noticed only for IPv4-mapped IPv6 addresses.
>> 
>> The `man connect` documentation on MacOSX states that even `disconnectx` can be used to disconnect datagram sockets. The commit here does that change to use `disconnectx` for MacOSX. Tests have been successfully run on some older Mac setups  to make sure this change passes there as well.
>> 
>> Currently `tier1`, `tier2` and `tier3` run is in progress across various OS.
>> 
>> No additional tests have been added for this change since the many existing (failing) tests already cover this use case.
>
> Jaikiran Pai has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Alan's suggestion - add @bug to just one test
>  - Revert "add @bug 8285515 to testcases that failed without this change"
>    
>    This reverts commit fd05ea6028edaad32b4b4160328792e889e14843.

Marked as reviewed by alanb (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/8445