On 01/15/2013 09:55 AM, Alan Bateman wrote:
On 14/01/2013 23:55, Doug Lea wrote:
Thanks to Alan and Aleksey for noticing this and to Chris for
offering some serialPersistentFields incantations!
(The only way to serialize a TLR represents a strange abuse to
begin with. You'd need to save the result of
ThreadLocalRandom.current() in a field of a serialized object.
Which would be a terrible idea ...)
It does seem nonsensical. Given that the padding isn't used then the
simplest thing might be to do "nothing", meaning treat this update as
an API change that changes the serialized form. I don't see any
compatibility issues as deserialization on an older release will just
leave the padding fields with their default values (and as they are
unused then it shouldn't matter). I think this would be simplest than
adding serialPersistentFields and a writeObject to write these unused
fields.
And one more thing. With moving of fields off the TLR object, the
semantics of de-serialization change. JDK7 TLR deserializes into an
instance which is not thread-bound with the copy of the seed of original
instance. So serializing/deserializing acts as a form of cloning the
instance and detaching the copy from the thread. Proposed TLR can't keep
this semantics (unless it is modeled as a private subclass of TLR for
example which overrides existing logic and provides a writeReplace()
method that replaces it with plain TLR instance before serializing).
Regards, Peter
