RFR 8072466: Deadlock when starting MulticastSocket and DatagramSocket

[Ivan Gerasimov]

Hi everyone!

The fix didn't bring enough attention back in February for some reason.
So, I'd like to re-request a review.

I've added a regression test, which reliably reproduces a deadlock on my 
local Windows 7 machine.

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8072466
WEBREV: http://cr.openjdk.java.net/~igerasim/8072466/00/webrev/

Sincerely yours,
Ivan

On 17.02.2015 9:54, Ivan Gerasimov wrote:
> Can someone help review this fix please?
>
> Comments/suggestions are welcome!
>
> Sincerely yours,
> Ivan
>
> On 06.02.2015 20:48, Ivan Gerasimov wrote:
>> Hello!
>>
>> There has been a deadlock in jdk-net code noticed on Windows.
>>
>> In the bug description there's a stack snippet showing that one of 
>> the deadlocked threads stuck in the native initialization code of 
>> DualStackPlainDatagramSocketImpl and the other -- in initializing of 
>> TwoStacksPlainDatagramSocketImpl.
>>
>> I suspect that the reason might be due to unordered initialization:
>> AbstractPlainDatagramSocketImpl, the parent of both classes above, 
>> explicitly loads TwoStacksPlainDatagramSocketImpl from the native 
>> init().
>> Thus, when both classes are being initialized concurrently, it may 
>> end with a clash.
>>
>>
>> Another issue noticed by Mark Sheppard is that the Windows version of 
>> DefaultDatagramSocketImplFactory.createDatagramSocketImpl() isn't 
>> synchronized, but reads/modifies shared data.
>> Thus, I removed modification and declared all the accessed fields final.
>>
>> Would you please help review the proposed fix?
>>
>> BUGURL: https://bugs.openjdk.java.net/browse/JDK-8072466
>> WEBREV: http://cr.openjdk.java.net/~igerasim/8072466/0/webrev/
>>
>> The build went fine on all the platforms, all the tests from 
>> (net|nio|io) passed Okay.
>>
>> Sincerely yours,
>> Ivan
>>
>>
>>
>
>
>