RFR: JDK-8235211: serviceability/attach/RemovingUnixDomainSocketTest.java fails with AttachNotSupportedException: Unable to open socket file

[Chris Plummer]

  228             // If the app hangs, we don't want to wait for the to 
test timeout.

Sorry, there was a typo in my suggestion. Should be "test to", not "to 
test".

thanks,

Chris

On 5/11/20 12:53 PM, Alex Menkov wrote:
> Hi Yasumasa, Serguei, Chris,
>
> Thank you for the feedback
> updated webrev (all suggestions are applied):
> http://cr.openjdk.java.net/~amenkov/jdk15/RemovingUnixDomainSocket/webrev.2/ 
>
>
> On 05/11/2020 00:31, serguei.spitsyn at oracle.com wrote:
>> Hi Alex,
>>
>> It looks good in general.
>> I have a couple of minor comments.
>>
>> http://cr.openjdk.java.net/~amenkov/jdk15/RemovingUnixDomainSocket/webrev/test/lib/jdk/test/lib/apps/LingeredApp.java.udiff.html 
>> + // if for a reason the app hangs, we don't want to wait test timeout
>>
>> Nit: replace: wait test timeout => wait for test timeout
>>
>> I hope, you remember about copyright comments update.
>>
>>
>> http://cr.openjdk.java.net/~amenkov/jdk15/RemovingUnixDomainSocket/webrev/src/hotspot/os/aix/attachListener_aix.cpp.udiff.html 
>>
>>
>> Q1: How useful is this variable? :
>> AixAttachListener::_shutdown = false;
>>
>>      Why is it needed on aix but not on other platforms?
>
> IFAIU AIX has issue with accept() - it hangs if the socket is closed.
> I don't think this _shutdown flag helps a lot, but I don't want to 
> make significant changes in the AIX code as I cannot test it.
>
> --alex
>
>>
>> Thanks,
>> Serguei
>>
>>
>> On 5/8/20 18:14, Alex Menkov wrote:
>>> Hi all,
>>>
>>> please review the fix for
>>> https://bugs.openjdk.java.net/browse/JDK-8235211
>>> webrev:
>>> http://cr.openjdk.java.net/~amenkov/jdk15/RemovingUnixDomainSocket/webrev/ 
>>>
>>>
>>> Test failures are caused by deadlock during attach listener restarting:
>>> check_socket_file function aborts socket listening and waits while 
>>> attach listener state becomes AL_NOT_INITIALIZED (it happens when 
>>> AttachListener::dequeue returns NULL).
>>> AttachListener::dequeue method is blocked in ThreadBlockInVM dtor.
>>> To solve it ThreadBlockInVM was added inside waiting cycle in 
>>> check_socket_file.
>>>
>>> Other changes:
>>> - made _listener (and _shutdown for aix) volatile as they are used 
>>> by 2 threads (attach listener thread and signal handler thread) 
>>> without synchronization;
>>> - added close() for listening socket on aix (before it had only 
>>> shutdown() for it);
>>> - additional logging and some cleanup in the test;
>>> - added handling of LingeredApp hang.
>>>
>>> --alex
>>