Implement the set_acquire_fence request of the
zwp_surface_synchronization_v1 interface.
The implementation uses the acquire fence in two ways:
1. If the associated buffer is used as GL render source, an
EGLSyncKHR is created from the fence and used to synchronize
access.
2. If the associated buffer is used as a plane framebuffer,
the acquire fence is treated as an in-fence for the atomic
commit operation. If in-fences are not supported and the buffer
has an acquire fence, we don't consider it for plane placement.
If the used compositor/renderer doesn't support explicit
synchronization, we don't advertise the protocol at all. Currently only
the DRM and X11 backends when using the GL renderer advertise the
protocol for production use.
Issues for discussion
---------------------
a. Currently, a server-side wait of EGLSyncKHR is performed before
using the EGLImage/texture during rendering. Unfortunately, it's not clear
from the specs whether this is generally safe to do, or we need to
sync before glEGLImageTargetTexture2DOES. The exception is
TEXTURE_EXTERNAL_OES where the spec mentions it's enough to sync
and then glBindTexture for any changes to take effect.
Changes in v5:
- Meson support.
- Make explicit sync server error reporting more generic, supporting
all explicit sync related interfaces not just
wp_linux_surface_synchronization.
- Fix typo in warning for missing EGL_KHR_wait_sync extension.
- Support minor version 2 of the explicit sync protocol (i.e., support
fences for opaque EGL buffers).
Changes in v4:
- Introduce and use fd_clear and and fd_move helpers.
- Don't check for a valid buffer when updating surface acquire fence fd
from state.
- Assert that pending state acquire fence fd is always clear
after a commit.
- Clarify that WESTON_CAP_EXPLICIT_SYNC applies to just the
renderer.
- Check for EGL_KHR_wait_sync before using eglWaitSyncKHR.
- Dup the acquire fence before passing to EGL.
Changes in v3:
- Keep acquire_fence_fd in surface instead of buffer.
- Clarify that WESTON_CAP_EXPLICIT_SYNC applies to both backend and
renderer.
- Move comment about non-ownership of in_fence_fd to struct
drm_plane_state definition.
- Assert that we don't try to use planes with in-fences when using the
legacy KMS API.
- Remove unnecessary info from wayland error messages.
- Handle acquire fence for subsurface commits.
- Guard against self-update in fd_update.
- Disconnect the client if acquire fence EGLSyncKHR creation or wait
fails.
- Use updated protocol interface names.
- User correct format specifier for resource ids.
- Advertise protocol for X11 backend with GL renderer.
Changes in v2:
- Remove sync file wait fallbacks.
- Raise UNSUPPORTED_BUFFER error at commit if we have an acquire
fence, but the committed buffer is not a valid linux_dmabuf.
- Don't put buffers with in-fences on planes that don't support
in-fences.
- Don't advertise explicit sync protocol if backend does not
support explicit sync.
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Introduce an internal API for dealing with linux sync files,
and use it in the codebase to replace ad-hoc sync file management.
The linux_sync_file_is_valid function is not currently used, but will be
utilized in upcoming commits to implement the
zwp_linux_explicit_synchronization_unstable_v1 protocol.
Changes in v5:
- Meson support.
Changes in v3:
- Use parameter name in function documentation.
- Move kernel UAPI to separate header file.
Changes in v2:
- Add function documentation
- Remove linux_sync_file_wait()
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Introduce support for the zwp_linux_explicit_synchronization_unstable_v1
protocol with an implementation of the zwp_linux_explicit_synchronization_v1
interface.
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.
In addition, 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
https://gitlab.freedesktop.org/wayland/wayland/issues/46).
Support for this protocol depends on the capabilities of the backend, so
we don't register it by default but provide a function which each
backend will need to call. In this commit only the headless backend when
using the noop renderer supports this to enable testing.
Note that the zwp_surface_synchronization_v1 interface, which contains
the core functionality of the protocol, is not implemented in this
commit. Support for it will be added in future commits.
Changes in v7:
- Added some information in the commit message about the benefits of
the explicit sync protocol.
Changes in v6:
- Fall back to advertising minor version 1 of the explicit sync protocol,
although we support minor version 2 features, until the new
wayland-protocols version is released.
Changes in v5:
- Meson support.
- Advertise minor version 2 of the explicit sync protocol.
Changes in v4:
- Enable explicit sync support in the headless backend for all
renderers.
Changes in v3:
- Use wl_resource_get_version() instead of hardcoding version 1.
- Use updated protocol interface names.
- Use correct format specifier for resource id.
- Change test name to 'linux-explicit-synchronization.weston'
(s/_/-/g).
Changes in v2:
- Move implementation to separate file so protocol can be registered
on demand by backends.
- Register protocol in headless+noop backend for testing purposes.
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Since the Meson install step is not written to try to set the suid bit
automatically, remind the user that weston-launch needs to be
setuid-root to work.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Helps people avoid wayland-egl if they don't want it.
Makes the check for wayland-egl explicit on the site instead of relying
on gl-renderer checking for it.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Helps people to avoid EGL and GLESv2 if they do not want them.
Stops using dep_egl and dep_glesv2 so that the human friendly error
message is alongside the dependency() statement, so that the message and
the statement can later be merged together once Meson offers the custom
error messages feature or something even more sophisticated.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Meson is a build system, currently implemented in Python, with multiple
output backends, including Ninja and Make. The build file syntax is
clean and easy to read unlike autotools. In practise, configuring and
building with Meson and Ninja has been observed to be much faster than
with autotools. Also cross-building support is excellent.
More information at http://mesonbuild.com
Since moving to Meson requires some changes from users in any case, we
took this opportunity to revamp build options. Most of the build options
still exist, some have changed names or more, and a few have been
dropped. The option to choose the Cairo flavour is not implemented since
for the longest time the Cairo image backend has been the only
recommended one.
This Meson build should be fully functional and it installs everything
an all-enabled autotools build does. Installed pkg-config files have
some minor differences that should be insignificant. Building of some
developer documentation that was never installed with autotools is
missing.
It is expected that the autotools build system will be removed soon
after the next Weston release.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Co-authored-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Alexandros Frantzis
Pekka Paalanen
Scott Anderson
Daniel Stone