RFR 8072466: Deadlock when starting MulticastSocket and DatagramSocket

[Ivan Gerasimov]

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
>
>
>