On Wed, 29 May 2024 07:42:01 GMT, Johan Sjölen <jsjo...@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. > > Today, the ChunkPools are allocated before main through static > initialization. That means that the ChunkPools exists when main starts > executing, so this is safe. Thanks @jdksjolen and @sspitsyn ! ------------- PR Comment: https://git.openjdk.org/jdk/pull/19425#issuecomment-2141338912
