[concurrency-interest] JLS 17.7 Non-atomic treatment of double and long : Android

Aleksey Shipilev aleksey.shipilev at oracle.com
Tue Apr 30 10:59:59 EDT 2013


On 04/30/2013 06:36 PM, Tim Halloran wrote:
> *JDK: DOES NOT split writes to longs into two parts (even 32-bit
> implementations)*
> 
> Of course we couldn't get this to happen on any 64-bit JVM, but we tried
> it out under Linux on 32-bit OpenJDK 1.7.0_21 it does NOT happen. The
> 32-bit JVM implementations follow the recommendation of the Java
> language specification.

This is where you should be careful about the interpretations.

You can claim the splitting occurs once you see one, but if you see no
splitting, your can not claim it does not occur. In my own internal
tests, every 32-bit x86 OpenJDK-derived VM experiences the long splits.

-Aleksey.


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