GitLab

Clarify that after zwp_buffer_release_v1 events, otherwise unused
buffers can be reused without any additional implicit synchronization.
This is in contrast to wl_buffer.release, which doesn't guarantee that
implicit synchronization is not required to safely use a buffer after
the event is received.
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>

Graphics APIs are expected to use this protocol under the hood, and
since there can only be one user of explicit synchronization per
surface, warn about using the protocol directly in such cases.
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>

Add opaque EGL buffers to the supported buffer types for use with the
explicit synchronization protocol. Opaque EGL buffers rely on the same
EGL implementation in both the compositor and clients, which makes it
straightforward to manage client expectations about fence support for
such buffers.

Also make it clearer that implementations are free to support other
buffer types beyond the required ones.
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>

This protocol enables explicit synchronization of asynchronous graphics
operations on buffers on a per-commit basis. Support is currently
limited to dmabuf buffers and dma_fence fence FDs.

Explicit synchronization provides a more versatile notification
mechanism for buffer readiness and availability, and can be used to
improve efficiency by integrating with related functionality in display
and graphics APIs.

This protocol is also useful in ChromeOS ARC++ (running Android apps
inside ChromeOS, using Wayland as the communication protocol), where it
can enable integration of the ChromeOS compositor with the explicit
synchronization mechanisms of the Android display subsystem.

Finally, the per-commit nature of the release events provided by this
protocol potentially offers a solution to a deficiency of the
wl_buffer.release event (see
wayland#46).
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Daniel Stone <daniels@collabora.com>
[Pekka: dropped Reveman from maintainers]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>