JDK 14 RFR of JDK-8232230: Suppress warnings on non-serializable non-transient instance fields in java.util.concurrent

[Joe Darcy]

Hi Martin,

Hmm. Sorry about that; I thought I was sending something which compiled, 
but clearly made a mistake somewhere in the tool chain.

It is possible at some cost to have a SerializableConditionImpl that had 
a Serializable field and a Condition field that both pointed to same 
object and forwarded methods calls appropriately. However, that adds an 
extra layer of objects and indirections.

-Joe

On 10/16/2019 6:11 PM, Martin Buchholz wrote:
>
>
> On Wed, Oct 16, 2019 at 3:56 PM Joe Darcy <joe.darcy at oracle.com 
> <mailto:joe.darcy at oracle.com>> wrote:
>
>
>     FWIW, this code compiles in javac
>
>          public interface SerializableCondition extends Condition,
>     Serializable {
>              public static <C extends Condition & Serializable>
>                                       SerializableCondition transform(C
>     condition) {
>                  return condition;
>              }
>          }
>
>     and objects of existing types like
>     AbstractQueuedLongSynchronizer.ConditionObject seem to get
>     "converted"
>     as desired.
>
>
> I actually tried this ...
> ---
> import java.io.Serializable;
> import java.util.concurrent.locks.Condition;
>
> public interface SerializableCondition
>     extends Condition, Serializable {
>     public static <C extends Condition & Serializable>
>       SerializableCondition transform(C condition) {
>         return condition;
>     }
> }
> ---
> ... and got:
>
> ==> javac -source 14 -Xlint:all SerializableCondition.java
> SerializableCondition.java:8: error: incompatible types: C cannot be 
> converted to SerializableCondition
>         return condition;
>                ^
>   where C is a type-variable:
>     C extends Condition,Serializable declared in method <C>transform(C)
> 1 error