On 29/09/16 05:31, David Holmes wrote: > > On 29/09/2016 10:49 AM, Carsten Varming wrote:
>> Because String has final fields there is a freeze action at the end >> of construction so that String instances are always safely published >> even if not "safely published". >> >> >> I always thought that the freeze action only freezes final fields. The >> hash field in String is not final and example 17.5-1 is applicable as >> far as I can see >> (https://docs.oracle.com/javase/specs/jls/se8/html/jls-17.html#jls-17.5). Has >> the memory model changed in JDK9 to invalidate example 17.5-1 or I am >> missing something about String. > > Sorry - I was confusing what the spec says versus what the VM actually > does - as Vitaly pointed out. A HotSpot back end could rewrite the constructor so that the last final field to be written used a store release instruction. Whether it should is another matter: I suppose it would be rather risky. Andrew.
