commit 2d230aa0b5d443e2165941e7d8c22225720a2be7
author Martin Kustermann <kustermann@google.com> Wed May 17 11:23:28 2023 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed May 17 11:23:28 2023 +0000
tree f947f1acf428b2b2e7d1c4d5af58b616c4379b73
parent 4c20cedd3031979f8eed536d9c1ebeb76521d5c5

[vm/ffi] Move ffi-callback related state from Thread to ObjectStore, move jit trampolines from Isolate to IsolateGroup

The ffi-callback related information on the [Thread] object is metadata
corresponding to ffi-callback-trampoline [Function] objects. There is
nothing thread or isolate specific about it.

Moving it away from [Thread] is needed because an [Isolate] can
have different [Thread] objects across its lifetime (see [0]): When
the stack of an isolate is empty, we reserve now the right to
re-cycle the [Thread]. If the isolate later runs again, it may
get a new [Thread] object.

This CL moves this information from [Thread] to the [ObjectStore]. In
addition we make the compiler be responsible for populating this
metadata - instead of doing this per-call site of
`Pointer.fromFunction()`. It will be preserved across snapshot writing
& snapshot reading (for AppJIT as well as AppAOT).

Similarly the JIT trampolines that are on Isolate aren't isolate
specific and can go to [IsolateGroup]. This simplifies doing the above
as the compiler can allocate those as well.

The effect is that [Thread] object gets smaller, GC doesn't have to
visit the 2 slots per-thread. It comes at expense of 2 more loads
when invoking the callback.

[0] https://dart-review.googlesource.com/c/sdk/+/297920

TEST=Regression test is vm/ffi{,_2}/invoke_callback_after_suspension_test

Change-Id: Ifde46a9f6e79819b5c0e359c3d3998d1d93b9b1e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/303700
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Liam Appelbe <liama@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>