Peter Cai
76f4ae4a73
Also adjust the build scripts so that we don't just export one big Rust file...
261 lines
12 KiB
XML
261 lines
12 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<protocol name="linux_drm_syncobj_v1">
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<copyright>
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Copyright 2016 The Chromium Authors.
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Copyright 2017 Intel Corporation
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Copyright 2018 Collabora, Ltd
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Copyright 2021 Simon Ser
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
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and/or sell copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice (including the next
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paragraph) shall be included in all copies or substantial portions of the
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Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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DEALINGS IN THE SOFTWARE.
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</copyright>
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<description summary="protocol for providing explicit synchronization">
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This protocol allows clients to request explicit synchronization for
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buffers. It is tied to the Linux DRM synchronization object framework.
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Synchronization refers to co-ordination of pipelined operations performed
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on buffers. Most GPU clients will schedule an asynchronous operation to
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render to the buffer, then immediately send the buffer to the compositor
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to be attached to a surface.
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With implicit synchronization, ensuring that the rendering operation is
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complete before the compositor displays the buffer is an implementation
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detail handled by either the kernel or userspace graphics driver.
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By contrast, with explicit synchronization, DRM synchronization object
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timeline points mark when the asynchronous operations are complete. When
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submitting a buffer, the client provides a timeline point which will be
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waited on before the compositor accesses the buffer, and another timeline
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point that the compositor will signal when it no longer needs to access the
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buffer contents for the purposes of the surface commit.
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Linux DRM synchronization objects are documented at:
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https://dri.freedesktop.org/docs/drm/gpu/drm-mm.html#drm-sync-objects
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Warning! The protocol described in this file is currently in the testing
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phase. Backward compatible changes may be added together with the
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corresponding interface version bump. Backward incompatible changes can
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only be done by creating a new major version of the extension.
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</description>
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<interface name="wp_linux_drm_syncobj_manager_v1" version="1">
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<description summary="global for providing explicit synchronization">
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This global is a factory interface, allowing clients to request
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explicit synchronization for buffers on a per-surface basis.
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See wp_linux_drm_syncobj_surface_v1 for more information.
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</description>
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<request name="destroy" type="destructor">
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<description summary="destroy explicit synchronization factory object">
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Destroy this explicit synchronization factory object. Other objects
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shall not be affected by this request.
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</description>
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</request>
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<enum name="error">
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<entry name="surface_exists" value="0"
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summary="the surface already has a synchronization object associated"/>
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<entry name="invalid_timeline" value="1"
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summary="the timeline object could not be imported"/>
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</enum>
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<request name="get_surface">
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<description summary="extend surface interface for explicit synchronization">
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Instantiate an interface extension for the given wl_surface to provide
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explicit synchronization.
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If the given wl_surface already has an explicit synchronization object
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associated, the surface_exists protocol error is raised.
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Graphics APIs, like EGL or Vulkan, that manage the buffer queue and
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commits of a wl_surface themselves, are likely to be using this
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extension internally. If a client is using such an API for a
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wl_surface, it should not directly use this extension on that surface,
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to avoid raising a surface_exists protocol error.
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</description>
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<arg name="id" type="new_id" interface="wp_linux_drm_syncobj_surface_v1"
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summary="the new synchronization surface object id"/>
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<arg name="surface" type="object" interface="wl_surface"
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summary="the surface"/>
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</request>
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<request name="import_timeline">
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<description summary="import a DRM syncobj timeline">
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Import a DRM synchronization object timeline.
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If the FD cannot be imported, the invalid_timeline error is raised.
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</description>
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<arg name="id" type="new_id" interface="wp_linux_drm_syncobj_timeline_v1"/>
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<arg name="fd" type="fd" summary="drm_syncobj file descriptor"/>
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</request>
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</interface>
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<interface name="wp_linux_drm_syncobj_timeline_v1" version="1">
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<description summary="synchronization object timeline">
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This object represents an explicit synchronization object timeline
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imported by the client to the compositor.
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</description>
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<request name="destroy" type="destructor">
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<description summary="destroy the timeline">
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Destroy the synchronization object timeline. Other objects are not
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affected by this request, in particular timeline points set by
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set_acquire_point and set_release_point are not unset.
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</description>
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</request>
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</interface>
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<interface name="wp_linux_drm_syncobj_surface_v1" version="1">
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<description summary="per-surface explicit synchronization">
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This object is an add-on interface for wl_surface to enable explicit
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synchronization.
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Each surface can be associated with only one object of this interface at
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any time.
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Explicit synchronization is guaranteed to be supported for buffers
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created with any version of the linux-dmabuf protocol. Compositors are
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free to support explicit synchronization for additional buffer types.
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If at surface commit time the attached buffer does not support explicit
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synchronization, an unsupported_buffer error is raised.
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As long as the wp_linux_drm_syncobj_surface_v1 object is alive, the
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compositor may ignore implicit synchronization for buffers attached and
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committed to the wl_surface. The delivery of wl_buffer.release events
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for buffers attached to the surface becomes undefined.
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Clients must set both acquire and release points if and only if a
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non-null buffer is attached in the same surface commit. See the
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no_buffer, no_acquire_point and no_release_point protocol errors.
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If at surface commit time the acquire and release DRM syncobj timelines
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are identical, the acquire point value must be strictly less than the
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release point value, or else the conflicting_points protocol error is
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raised.
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</description>
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<request name="destroy" type="destructor">
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<description summary="destroy the surface synchronization object">
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Destroy this surface synchronization object.
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Any timeline point set by this object with set_acquire_point or
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set_release_point since the last commit may be discarded by the
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compositor. Any timeline point set by this object before the last
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commit will not be affected.
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</description>
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</request>
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<enum name="error">
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<entry name="no_surface" value="1"
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summary="the associated wl_surface was destroyed"/>
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<entry name="unsupported_buffer" value="2"
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summary="the buffer does not support explicit synchronization"/>
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<entry name="no_buffer" value="3" summary="no buffer was attached"/>
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<entry name="no_acquire_point" value="4"
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summary="no acquire timeline point was set"/>
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<entry name="no_release_point" value="5"
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summary="no release timeline point was set"/>
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<entry name="conflicting_points" value="6"
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summary="acquire and release timeline points are in conflict"/>
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</enum>
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<request name="set_acquire_point">
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<description summary="set the acquire timeline point">
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Set the timeline point that must be signalled before the compositor may
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sample from the buffer attached with wl_surface.attach.
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The 64-bit unsigned value combined from point_hi and point_lo is the
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point value.
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The acquire point is double-buffered state, and will be applied on the
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next wl_surface.commit request for the associated surface. Thus, it
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applies only to the buffer that is attached to the surface at commit
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time.
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If an acquire point has already been attached during the same commit
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cycle, the new point replaces the old one.
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If the associated wl_surface was destroyed, a no_surface error is
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raised.
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If at surface commit time there is a pending acquire timeline point set
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but no pending buffer attached, a no_buffer error is raised. If at
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surface commit time there is a pending buffer attached but no pending
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acquire timeline point set, the no_acquire_point protocol error is
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raised.
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</description>
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<arg name="timeline" type="object" interface="wp_linux_drm_syncobj_timeline_v1"/>
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<arg name="point_hi" type="uint" summary="high 32 bits of the point value"/>
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<arg name="point_lo" type="uint" summary="low 32 bits of the point value"/>
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</request>
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<request name="set_release_point">
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<description summary="set the release timeline point">
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Set the timeline point that must be signalled by the compositor when it
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has finished its usage of the buffer attached with wl_surface.attach
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for the relevant commit.
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Once the timeline point is signaled, and assuming the associated buffer
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is not pending release from other wl_surface.commit requests, no
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additional explicit or implicit synchronization with the compositor is
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required to safely re-use the buffer.
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Note that clients cannot rely on the release point being always
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signaled after the acquire point: compositors may release buffers
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without ever reading from them. In addition, the compositor may use
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different presentation paths for different commits, which may have
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different release behavior. As a result, the compositor may signal the
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release points in a different order than the client committed them.
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Because signaling a timeline point also signals every previous point,
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it is generally not safe to use the same timeline object for the
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release points of multiple buffers. The out-of-order signaling
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described above may lead to a release point being signaled before the
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compositor has finished reading. To avoid this, it is strongly
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recommended that each buffer should use a separate timeline for its
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release points.
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The 64-bit unsigned value combined from point_hi and point_lo is the
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point value.
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The release point is double-buffered state, and will be applied on the
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next wl_surface.commit request for the associated surface. Thus, it
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applies only to the buffer that is attached to the surface at commit
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time.
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If a release point has already been attached during the same commit
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cycle, the new point replaces the old one.
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If the associated wl_surface was destroyed, a no_surface error is
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raised.
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If at surface commit time there is a pending release timeline point set
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but no pending buffer attached, a no_buffer error is raised. If at
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surface commit time there is a pending buffer attached but no pending
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release timeline point set, the no_release_point protocol error is
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raised.
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</description>
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<arg name="timeline" type="object" interface="wp_linux_drm_syncobj_timeline_v1"/>
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<arg name="point_hi" type="uint" summary="high 32 bits of the point value"/>
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<arg name="point_lo" type="uint" summary="low 32 bits of the point value"/>
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</request>
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</interface>
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</protocol>
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