RFR: 8187809: UseMembar should be set true and deprecate the flag

[Robbin Ehn]

Hi,

I forgot to say, UseMembar have been tested heavily on our supported platforms.
This particular changeset just passed sanity test of tier 1-2.

Thanks, Robbin

On 2017-11-08 21:48, Robbin Ehn wrote:
> Hi all, please review!
> 
> This patch set the default technique for reading thread state to memory barriers instead of using the asymmetric dekker 
> synchronization on all platforms. We also deprecate the option and starting the removal process. There have been 
> discussion with people involved in all platforms and we will have another discussion before obsoleting the flag to make 
> sure no issue have been found.
> 
> More info in CSR:
> https://bugs.openjdk.java.net/browse/JDK-8187812
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8187809
> 
> Code:
> http://cr.openjdk.java.net/~rehn/8187809/webrev/
> 
> Thanks, Robbin