RFR: JDK-8326898: NSK tests should listen on loopback addresses only [v2]

[Alex Menkov]

On Tue, 5 Mar 2024 02:24:50 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

>> Many NSK tests create socket channel for test/target interprocess communication.
>> The change updates server side to listen only on loopback interface.
>> 
>> Testing - all tests that use then functionality:
>>  - test/hotspot/jtreg/vmTestbase/nsk/jdb, test/hotspot/jtreg/vmTestbase/nsk/jdi, test/hotspot/jtreg/vmTestbase/nsk/jdwp, test/hotspot/jtreg/vmTestbase/nsk/aod, test/hotspot/jtreg/vmTestbase/nsk/jvmti/AttachOnDemand
>
> Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   SocketIOPipe.createClientIOPipe and getTestHost()/getDebugeeHost()

Updated connecting side of the IOPipe
Also fixed DebugeeArgumentHandler.getTestHost() (DebugeeArgumentHandler.getDebugeeHost() uses the value) to return empty string.
getTestHost()/getDebugeeHost() are used in some scenarios:
- to create arguments for listening debugee (in the case `":<port>"` is passed, so debugee listens on loopback address);
- to connect to a socket (then InetAddress.getByName returns loockback address).

All tests that use then functionality pass

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PR Comment: https://git.openjdk.org/jdk/pull/18053#issuecomment-1977837845