Integrated: 8333047: Remove arena-size-workaround in jvmtiUtils.cpp
Thomas Stuefe
stuefe at openjdk.org
Fri May 31 06:53:04 UTC 2024
On Tue, 28 May 2024 12:36:41 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:
> In `JvmtiUtil::single_threaded_resource_area()`, we create a resource area that is supposed to work even if the current thread is not attached yet and there is no associated Thread or the Thread has no valid ResourceArea.
>
> It contains a workaround:
>
>
> // lazily create the single threaded resource area
> // pick a size which is not a standard since the pools don't exist yet
> _single_threaded_resource_area = new (mtInternal) ResourceArea(Chunk::non_pool_size);
>
>
> It specifies a non-standard chunk size to circumvent the chunk-pool-based allocation in the RA constructor, ensuring that only malloc is used. This is because in the old days the ChunkPools had been allocated from C-Heap and there was a time window when no chunk pools were live yet.
>
> This is quirky and a bit ugly. It is also unnecessary since [JDK-8272112](https://bugs.openjdk.org/browse/JDK-8272112) (since JDK 18). We now create chunk pools as global objects, so they are live as soon as the libjvm C++ initialization ran. We can remove this workaround and the comment.
>
> ---
>
> Tests: GHAs.
> I also manually called this function, and allocated from the resulting ResourceArea, at the very beginning of CreateJavaVM. I made sure that both allocations and follow-up-chunk-allocation worked even this early in VM life.
This pull request has now been integrated.
Changeset: ba323b51
Author: Thomas Stuefe <stuefe at openjdk.org>
URL: https://git.openjdk.org/jdk/commit/ba323b515d8821895356507bdb1e94df0776dd5a
Stats: 8 lines in 3 files changed: 0 ins; 3 del; 5 mod
8333047: Remove arena-size-workaround in jvmtiUtils.cpp
Reviewed-by: jsjolen, sspitsyn
-------------
PR: https://git.openjdk.org/jdk/pull/19425
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