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.
-------------
Commit messages:
- copyrights
- remove non_pool_size
- start
Changes: https://git.openjdk.org/jdk/pull/19425/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19425&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8333047
Stats: 8 lines in 3 files changed: 0 ins; 3 del; 5 mod
Patch: https://git.openjdk.org/jdk/pull/19425.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/19425/head:pull/19425
PR: https://git.openjdk.org/jdk/pull/19425
