<i18n dev> RFR: 8366178: Implement JEP 526: Lazy Constants (Second Preview) [v7]

[Per Minborg]

On Mon, 13 Oct 2025 13:44:07 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Update src/java.base/share/classes/java/lang/LazyConstant.java
>>   
>>   Co-authored-by: Maurizio Cimadamore <54672762+mcimadamore at users.noreply.github.com>
>
> src/java.base/share/classes/java/lang/LazyConstant.java line 192:
> 
>> 190:  *          The {@code LazyConstant} type is not {@link Serializable}.
>> 191:  *          <p>
>> 192:  *          It is not recommended putting lazy constants into equality-based collections
> 
> Not sure what you mean here. It seems like the javadoc for `equals` says that it triggers initialization, so it should be ok?

Formally, it is ok, but may result in strange side effects if we, for example, put a key of type LazyConstant in a map. It will then be initialized immediately (upon `map.put()`), and the put operation can therefore have non-obvious side effects.

> src/java.base/share/classes/java/lang/LazyConstant.java line 276:
> 
>> 274:      * this method might block or throw.
>> 275:      *
>> 276:      * @implSpec The order of potential initialization triggering is specified as:
> 
> Do we really need to specify this?

This is a corner case, but we might have two uninitialized LCs. The order in which they get computed might be significant (e.g., they operate on shared data structures).

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PR Review Comment: https://git.openjdk.org/jdk/pull/27605#discussion_r2426507366
PR Review Comment: https://git.openjdk.org/jdk/pull/27605#discussion_r2426513556