8026344: j.u.c.a *Adder and *Accumulator extend a package private class that is Serializable

[roger riggs]

Hi Alan,

That looks fine.

The signature of the readObject methods usually has the return type Object
even though in this case it should never be used. And a method comment 
would be nice
saying why it always throws an exception.

I might have been tempted to conserve on classes and code duplication to
share a serialization proxy between the classes and maybe even shorten 
the name.
But it is hard to argue with the simplicity and directness of this design.

The test is sufficient for a smoke test until the full serialization 
tests are written/updated.

(Not a reviewer)

Roger



On 10/23/2013 10:06 AM, Alan Bateman wrote:
>
> j.u.c.atomic.{Double,Long}.{Accumulator,Adder} extend a 
> package-private class Striped64 that does striping on 64-bit values. 
> This super type is Serializable by way of extending Number. Striped64 
> doesn't contribute any serial fields but its name does leak into the 
> serial stream because there is a descriptor for the super type when it 
> is also serializable. Those that write conformance tests have noticed 
> this.
>
> In practical terms this is a bit of a non-issue but the reference to 
> Striped64 can be removed from the serial stream by changing these four 
> to use a serialization proxy. Doug has gone ahead and changed the 
> classes in jsr166 CVS and we need to bring these changes into jdk8/tl 
> by the ZBB date.
>
> The webrev with the proposed changes is here:
>
> http://cr.openjdk.java.net/~alanb/8026344/webrev/
>
> A minor difference with what is currently in the CVS is that I've 
> added a link in the writeReplace javadoc to the proxy class. I've also 
> added a simple test as I didn't find any tests in the jdk repository 
> that exercise serialization of these classes.
>
> -Alan.
>