> This is a dependent PR containing a cleanup of the so called *heap sessions*. > Heap sessions are used in two cases: > > * when a buffer segment is created, to keep the original buffer instance > reachable > * when a loader symbol lookup is created, to keep the classloader instance > reachable > > Spinning new sessions in these cases seems unnecessary, and inconsistent with > what we do for segments backed by on-heap arrays, whose session is set to the > global session. In that case, it's up to the segment to keep the underlying > array reachable. I think that's a better model. > > This patch adds the ability to attach Object references to native and mapped > memory segments, so that we can attach loader/byte buffer instances to these > segments, keeping them alive. This means that, in these cases we can go back > to just use the global memory session, like we do for array segments. > > This simplifies the implementation, makes the documentation more consistent, > and also simplifies the user model, as it removes a concept (of heap session) > that is not really documented anywhere. In fact, the javadoc for > MemorySegment::ofBuffer claims, (wrongly!) that the session of the resulting > segment is the global session - but that's not the case.
Maurizio Cimadamore has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains eight commits: - Initial push - Revert implicit vs. heap session changes - Unify heap vs. implicit scopes - Merge branch 'master' into memory_session_cleanup - Fix issue in Direct-X-Buffer template - Simplify and drop the state class - Add missing files - Initial push ------------- Changes: https://git.openjdk.org/jdk19/pull/39/files Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=39&range=01 Stats: 577 lines in 28 files changed: 53 ins; 125 del; 399 mod Patch: https://git.openjdk.org/jdk19/pull/39.diff Fetch: git fetch https://git.openjdk.org/jdk19 pull/39/head:pull/39 PR: https://git.openjdk.org/jdk19/pull/39
