On Wed, 15 Jul 2026 21:12:59 GMT, Maurizio Cimadamore <[email protected]> 
wrote:

>> The methods `load()`, `unload()`, `isLoaded()`, and `force()` in 
>> `MemorySegment` currently delegate to `ScopedMemoryAccess` through a set of 
>> `@Scoped` methods, after which the implementation calls into 
>> `java.nio.MappedMemoryUtils`. This means that, when a shared scope is closed 
>> during a call to one of these methods, an exception can be installed at any 
>> point during the execution of the util method.
>> 
>> The problem is that some parts of these methods are not able to handle such 
>> exceptions being installed.
>> 
>> We've had some previous discussion about these methods not really needing to 
>> be `@Scoped` in the first place, but instead being able to rely on paired 
>> acquire/release of the session being accessed. This code is not as 
>> performance critical compared to a scoped memory access, since we're doing a 
>> native call any way.
>> 
>> To avoid issues with exceptions being installed in surprising places, this 
>> patch switches the named methods to use acquire/release instead of being 
>> `@Scoped`. This changes the behavior of these methods slightly: they now 
>> keep the scope alive during the execution of the method. I've updated the 
>> doc, borrowing from existing text in the `Linked::downcallHandle` docs, to 
>> explain that a scope closure may now fail during the execution of one of 
>> these methods.
>> 
>> Does this seem like the right tradeoff?
>> 
>> ---------
>> - [x] I confirm that I make this contribution in accordance with the 
>> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai).
>
> src/java.base/share/classes/java/lang/foreign/Linker.java line 635:
> 
>> 633:      *         {@code A.isAccessibleBy(T) == true}.
>> 634:      *         Otherwise, the invocation throws {@link 
>> WrongThreadException}; and</li>
>> 635:      *     <li>{@code A} is <a 
>> href="MemorySegment.html#segment-alignment">kept alive</a>
> 
> The link seems wrong

Also consider using `{@linkplain MemorySegment##keep-alive kept alive}` instead 
of html tags.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/31918#discussion_r3591628851

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