commit 8c55820034cee5d7146587f35ab04c9456308244
author Lokbondo Kung <lokokung@google.com> Mon Jun 23 14:32:58 2025 -0700
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon Jun 23 14:32:58 2025 -0700
tree 601eb75d8eee4051d945f67f39eed1d6bb5b5d07
parent 676d919522185dec21d2471fc9a8d3fd32894176

[dawn][native] Updates buffer mapping w.r.t device lock.

The crux of this change is to make it such that users can
re-entrantly use *MappedRange functions and Unmap inside of
the MapAsync callback if the callback is successful. If the
callback was not successful, re-entrant API usage is not
allowed.

- Renames GetMappedPointer->GetMappedPointerImpl for the frontend
  class, and then implements GetMappedPointer to take into account
  the staging buffer. This is more in line with how the rest of
  the Buffer's *Impl functions look and are handled. This also
  allows some cleanup of overly specialized code.
- Coalesces buffer mapping state for clarity.
- Updates |completedSerial| in QueueAndSerial to be atomic
  because spontaneous events may modify and read it concurrently.
- Removes device wide lock acquiring when calling GetMappedRange
  and its variants now that we have an atomic to guarantee some
  code paths to be valid. This should increase performance on
  these buffers also.
- Refactors Unmap a bit to differentiate internal and external
  usages.
- Manually scope the device lock in Unmap to ensure that the
  callbacks are triggered in the right places.

Bug: 412761228, 418165343, 42241400, 40643114, 417802523
Change-Id: If5ea22f81c6d305d1dee90eb3cf6276061e2f888
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/242715
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Loko Kung <lokokung@google.com>