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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_GFX_PRESENTATION_FEEDBACK_H_
#define UI_GFX_PRESENTATION_FEEDBACK_H_
#include <stdint.h>
#include <optional>
#include "base/time/time.h"
#include "build/build_config.h"
#include "ui/gfx/ca_layer_result.h"
namespace gfx {
// The feedback for gl::GLSurface methods |SwapBuffers|, |SwapBuffersAsync|,
// |SwapBuffersWithBounds|, |PostSubBuffer|, |PostSubBufferAsync|,
// |CommitOverlayPlanes|,|CommitOverlayPlanesAsync|, etc.
struct PresentationFeedback {
enum Flags {
// The presentation was synchronized to VSYNC.
kVSync = 1 << 0,
// The presentation |timestamp| is converted from hardware clock by driver.
// Sampling a clock in user space is not acceptable for this flag.
kHWClock = 1 << 1,
// The display hardware signalled that it started using the new content. The
// opposite of this is e.g. a timer being used to guess when the display
// hardware has switched to the new image content.
kHWCompletion = 1 << 2,
// The presentation of this update was done zero-copy. Possible zero-copy
// cases include direct scanout of a fullscreen surface and a surface on a
// hardware overlay.
kZeroCopy = 1 << 3,
// The presentation of this update failed. |timestamp| is the time of the
// failure.
kFailure = 1 << 4,
};
PresentationFeedback() = default;
PresentationFeedback(base::TimeTicks timestamp,
base::TimeDelta interval,
uint32_t flags)
: timestamp(timestamp), interval(interval), flags(flags) {}
static PresentationFeedback Failure() {
return {base::TimeTicks::Now(), base::TimeDelta(), Flags::kFailure};
}
bool failed() const { return !!(flags & Flags::kFailure); }
friend bool operator==(const PresentationFeedback&,
const PresentationFeedback&) = default;
// The time when a buffer begins scan-out. If a buffer is never presented on
// a screen, the |timestamp| will be set to the time of the failure.
base::TimeTicks timestamp;
// An estimated interval from the |timestamp| to the next refresh.
base::TimeDelta interval;
// A combination of Flags. It indicates the kind of the |timestamp|.
uint32_t flags = 0;
// The following are additional timestamps that are reported if available on
// the underlying platform. If not available, the timestamp is set to 0.
// A buffer sent to the system compositor or display controller for
// presentation is returned to chromium's compositor with an out fence for
// synchronization. This fence indicates when reads from this buffer for
// presentation (on the GPU or display controller) have been finished and it
// is safe to write new data to this buffer. Since this fence may not have
// been signalled when the swap for a new frame is issued, this timestamp is
// meant to track the latency from when a swap is issued on the GPU thread to
// when the GPU can start rendering to this buffer.
base::TimeTicks available_timestamp;
// The time when the GPU has finished completing all the drawing commands on
// the primary plane. On Android, SurfaceFlinger does not latch to a buffer
// until this fence has been signalled.
base::TimeTicks ready_timestamp;
// The time when the primary plane is latched by the system compositor for its
// next rendering update. On Android this corresponds to the SurfaceFlinger
// latch time.
base::TimeTicks latch_timestamp;
// The time when write operations have completed, corresponding to the time
// when rendering on the GPU finished.
base::TimeTicks writes_done_timestamp;
#if BUILDFLAG(IS_APPLE)
gfx::CALayerResult ca_layer_error_code = gfx::kCALayerSuccess;
#endif
// A unique ID used by the graphics pipeline to trace each individual frame
// swap. This value is present only if the feedback is coming from/via
// viz::Display. It's set in viz::Display::DidReceivePresentationFeedback().
// It should only be used for performance tracing purposes. See also
// gpu::SwapBuffersCompleteParams.swap_trace_id and
// perfetto::protos::pbzero::ChromeTrackEvent.event_latency.display_trace_id.
std::optional<int64_t> display_trace_id;
};
} // namespace gfx
#endif // UI_GFX_PRESENTATION_FEEDBACK_H_
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