RFR: 8145680: Remove unnecessary explicit initialization of volatile variables in java.base

[Claes Redestad]

Hi,

the changes to java.net.URI stood out as a bit too intrusive for a 
cleanup like this, and there's precious little measurable benefit. I 
decided to break out those to a separate RFE and simplified this patch:

Webrev: http://cr.openjdk.java.net/~redestad/8145680/webrev.02

/Claes

On 2015-12-19 14:07, Claes Redestad wrote:
> Hi,
>
> initializing volatile fields to their default value has a well-known 
> performance penalty, and removing these should typically be safe. This 
> patch addresses java.base.
>
> There are however some corner cases that we need to check for, see 
> examples and discussion in 
> http://cs.oswego.edu/pipermail/concurrency-interest/2015-December/014767.html
>
> When meticulously going through and checking each usage for odd 
> pattern like this I accidentally did a bit of extra cleanup, mostly 
> addressing a number of cases where the volatile field was being read 
> twice. Sorry!
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8145680
>