On Wed, 4 Feb 2026 14:41:09 GMT, Frederic Parain <[email protected]> wrote:

> First batch of changes to remove potentially dangerous calls to 
> objArrayOopDesc::obj_at().
> Changes are more extensive than intended. In most cases, code modifications 
> consist in using a refArrayOop type instead of a objArrayOop type, because 
> most of the arrays the JVM deals with for its own purpose are always 
> reference arrays (because they are arrays of identity type elements). The 
> patch also adds a new API allowing the VM to request the allocation of a 
> reference array.
> Code dealing with user provided arrays must be ready to handle exceptions 
> when accessing objArrays.
> 
> This is a short term fix, fixing a few bugs, and trying to make the code more 
> robust using the meta-data types. For the long term, a better solution is 
> needed. Accesses to both arrays and fields are becoming more and more complex 
> because of the introduction of flattening, multiple layouts, additional 
> properties. Forcing enforcement at each access would be expensive and 
> wasteful, as the JVM usually operates on well-known objects or arrays. But 
> because of the increasing complexity, having a way to quickly check the 
> validity of an access would help making the VM code more robust.

This pull request has now been integrated.

Changeset: 5d5a5940
Author:    Frederic Parain <[email protected]>
URL:       
https://git.openjdk.org/valhalla/commit/5d5a5940de7a7c019153057d736fc5a6d872bb6f
Stats:     379 lines in 55 files changed: 148 ins; 41 del; 190 mod

8375306: [lworld] Investigate alternatives to flatArrayOopDesc::obj_at 
implementation

Co-authored-by: Stefan Karlsson <[email protected]>
Reviewed-by: coleenp, stefank, iwalulya

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

PR: https://git.openjdk.org/valhalla/pull/2033

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