tor-browser

CompositorVsyncScheduler.h (5999B)

---

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_layers_CompositorVsyncScheduler_h
#define mozilla_layers_CompositorVsyncScheduler_h

#include <stdint.h>  // for uint64_t

#include "mozilla/Monitor.h"    // for Monitor
#include "mozilla/RefPtr.h"     // for RefPtr
#include "mozilla/TimeStamp.h"  // for TimeStamp
#include "mozilla/gfx/Point.h"  // for IntSize
#include "mozilla/layers/SampleTime.h"
#include "mozilla/webrender/webrender_ffi.h"
#include "mozilla/VsyncDispatcher.h"
#include "mozilla/widget/CompositorWidget.h"
#include "nsISupportsImpl.h"

namespace mozilla {

class CancelableRunnable;
class Runnable;

namespace gfx {
class DrawTarget;
}  // namespace gfx

namespace layers {

class CompositorVsyncSchedulerOwner;

/**
* Manages the vsync (de)registration and tracking on behalf of the
* compositor when it need to paint.
* Turns vsync notifications into scheduled composites.
**/
class CompositorVsyncScheduler {
 NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorVsyncScheduler)

public:
 CompositorVsyncScheduler(CompositorVsyncSchedulerOwner* aVsyncSchedulerOwner,
                          widget::CompositorWidget* aWidget);

 /**
  * Notify this class of a vsync. This will trigger a composite if one is
  * needed. This must be called from the vsync dispatch thread.
  */
 void NotifyVsync(const VsyncEvent& aVsync);

 /**
  * Do cleanup. This must be called on the compositor thread.
  */
 void Destroy();

 /**
  * Notify this class that a composition is needed. This will trigger a
  * composition soon (likely at the next vsync). This must be called on the
  * compositor thread.
  */
 void ScheduleComposition(wr::RenderReasons aReasons);

 /**
  * Cancel any composite task that has been scheduled but hasn't run yet.
  *
  * Returns the render reasons of the canceled task if any.
  */
 wr::RenderReasons CancelCurrentCompositeTask();

 /**
  * Check if a composite is pending. This is generally true between a call
  * to ScheduleComposition() and the time the composite happens.
  */
 bool NeedsComposite();

 /**
  * Force a composite to happen right away, without waiting for the next vsync.
  * This must be called on the compositor thread.
  */
 void ForceComposeToTarget(wr::RenderReasons aReasons,
                           gfx::DrawTarget* aTarget,
                           const gfx::IntRect* aRect);

 /**
  * If a composite is pending, force it to trigger right away. This must be
  * called on the compositor thread. Returns true if there was a composite
  * flushed.
  */
 bool FlushPendingComposite();

 /**
  * Return the vsync timestamp of the last or ongoing composite. Must be called
  * on the compositor thread.
  */
 const SampleTime& GetLastComposeTime() const;

 /**
  * Return the vsync timestamp and id of the most recently received
  * vsync event. Must be called on the compositor thread.
  */
 const TimeStamp& GetLastVsyncTime() const;
 const TimeStamp& GetLastVsyncOutputTime() const;
 const VsyncId& GetLastVsyncId() const;

 /**
  * Update LastCompose TimeStamp to current timestamp.
  * The function is typically used when composition is handled outside the
  * CompositorVsyncScheduler.
  */
 void UpdateLastComposeTime();

private:
 virtual ~CompositorVsyncScheduler();

 // Post a task to run Composite() on the compositor thread, if there isn't
 // such a task already queued. Can be called from any thread.
 void PostCompositeTask(const VsyncEvent& aVsyncEvent,
                        wr::RenderReasons aReasons);

 // Post a task to run DispatchVREvents() on the VR thread, if there isn't
 // such a task already queued. Can be called from any thread.
 void PostVRTask(TimeStamp aTimestamp);

 /**
  * Cancel any VR task that has been scheduled but hasn't run yet.
  */
 void CancelCurrentVRTask();

 // This gets run at vsync time and "does" a composite (which really means
 // update internal state and call the owner to do the composite).
 void Composite(const VsyncEvent& aVsyncEvent, wr::RenderReasons aReasons);

 void ObserveVsync();
 void UnobserveVsync();

 void DispatchVREvents(TimeStamp aVsyncTimestamp);

 class Observer final : public VsyncObserver {
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorVsyncScheduler::Observer,
                                         override)

  public:
   explicit Observer(CompositorVsyncScheduler* aOwner);
   void NotifyVsync(const VsyncEvent& aVsync) override;
   void Destroy();

  private:
   virtual ~Observer();

   Mutex mMutex;
   // Hold raw pointer to avoid mutual reference.
   CompositorVsyncScheduler* mOwner;
 };

 CompositorVsyncSchedulerOwner* mVsyncSchedulerOwner;
 SampleTime mLastComposeTime;
 TimeStamp mLastVsyncTime;
 TimeStamp mLastVsyncOutputTime;
 VsyncId mLastVsyncId;

 bool mAsapScheduling;
 bool mIsObservingVsync;
 // Accessed on the compositor thread.
 wr::RenderReasons mRendersDelayedByVsyncReasons;
 TimeStamp mCompositeRequestedAt;
 int32_t mVsyncNotificationsSkipped;
 widget::CompositorWidget* mWidget;
 RefPtr<CompositorVsyncScheduler::Observer> mVsyncObserver;

 mozilla::Monitor mCurrentCompositeTaskMonitor;
 RefPtr<CancelableRunnable> mCurrentCompositeTask
     MOZ_GUARDED_BY(mCurrentCompositeTaskMonitor);
 // Accessed on multiple threads, guarded by mCurrentCompositeTaskMonitor.
 wr::RenderReasons mCurrentCompositeTaskReasons
     MOZ_GUARDED_BY(mCurrentCompositeTaskMonitor);

 mozilla::Monitor mCurrentVRTaskMonitor;
 RefPtr<CancelableRunnable> mCurrentVRTask
     MOZ_GUARDED_BY(mCurrentVRTaskMonitor);
};
}  // namespace layers
}  // namespace mozilla

#endif  // mozilla_layers_CompositorVsyncScheduler_h