RFR: 8267564: JDK-8252971 causes SPECjbb2015 socket exceptions on Windows when MKS is installed

[Michael McMahon]

On Fri, 4 Jun 2021 07:42:14 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> Hi,
>> 
>> This fixes a problem where unix domain sockets are available on Windows from third party winsock drivers (other than the Microsoft implementation in Windows 10/2019). These are available (unexpectedly) on earlier Windows releases and are not supported by Java. 
>> 
>> The fix is to search for the expected winsock service provider ID and specifically use that one when creating sockets. Previously, we just attempted to create a unix domain socket, and once that succeeded we assumed we had the right service provider.
>> 
>> I haven't included a regression test because the environment to reproduce the issue is not part of the standard test configuration. Also, the new code is well exercised by existing tests.
>> 
>> Thanks,
>> Michael.
>
> src/java.base/windows/native/libnio/ch/UnixDomainSockets.c line 101:
> 
>> 99:     if (g1->Data3 != g2->Data3)
>> 100:         return 0;
>> 101:     return !memcmp(g1->Data4, g2->Data4, 8);
> 
> I think this would be easier to understand if Data4 were compared in the same way as Data1-Data3.

I presume you mean compare each element of the array individually. I guess we can do that, as the function is only called once.

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PR: https://git.openjdk.java.net/jdk/pull/4339