cc/slim/delayed_scheduler.h

   1 // Copyright 2023 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_SLIM_DELAYED_SCHEDULER_H_
   6 #define CC_SLIM_DELAYED_SCHEDULER_H_
   7
   8 #include "base/component_export.h"
   9 #include "base/memory/raw_ptr.h"
  10 #include "cc/slim/scheduler.h"
  11 #include "components/viz/common/frame_sinks/begin_frame_args.h"
  12
  13 namespace cc::slim {
  14
  15 // DelayedScheduler is optimized specifically for the case of renderer-driven
  16 // scrolling of browser controls in the browser compositor on Android.
  17 // The design aims to immediately submit frame whenever scroll offset arrives
  18 // from the renderer:
  19 // * Expect `MaybeCompositeNow` to be called when scroll offset from renderer
  20 //   arrives.
  21 // * Cache BeginFrameArgs from `OnBeginFrameFromViz` and wait until either
  22 //   `MaybeCompositeNow` or until the next `OnBeginFrameFromViz`. This increases
  23 //   the latency for other cases that does not call `MaybeCompositeNow` by one
  24 //   frame.
  25 // * If `MaybeCompositeNow` is blocked from producing a frame due to some
  26 //   condition, immediately attempt producing from again if the condition
  27 //   changes.
  28 // TODO(boliu): Move this to //content after slim is enabled for browser
  29 // compositor on android.
  30 class COMPONENT_EXPORT(CC_SLIM) DelayedScheduler : public Scheduler {
  31  public:
  32   DelayedScheduler();
  33   ~DelayedScheduler() override;
  34
  35   void Initialize(SchedulerClient* client) override;
  36   void OnBeginFrameFromViz(
  37       const viz::BeginFrameArgs& begin_frame_args) override;
  38   void OnBeginFramePausedChanged(bool paused) override;
  39   void SetNeedsBeginFrame(bool needs_begin_frame) override;
  40   void SetIsSwapThrottled(bool is_swap_throttled) override;
  41   void MaybeCompositeNow() override;
  42
  43  private:
  44   void BeginFrameAndResetArgs(viz::BeginFrameArgs& args);
  45   void SendDidNotProduceFrameAndResetArgs(viz::BeginFrameArgs& args);
  46
  47   raw_ptr<SchedulerClient> client_ = nullptr;
  48
  49   viz::BeginFrameArgs unused_args_;
  50   bool needs_begin_frame_ = false;
  51   bool is_swap_throttled_ = false;
  52   bool missed_composite_now_ = false;
  53 };
  54
  55 }  // namespace cc::slim
  56
  57 #endif  // CC_SLIM_DELAYED_SCHEDULER_H_