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/* -*- 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/. */
/*
* Code to notify things that animate before a refresh, at an appropriate
* refresh rate. (Perhaps temporary, until replaced by compositor.)
*/
#ifndef nsRefreshDriver_h_
#define nsRefreshDriver_h_
#include "mozilla/FlushType.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Vector.h"
#include "mozilla/WeakPtr.h"
#include "nsTObserverArray.h"
#include "nsTArray.h"
#include "nsTHashtable.h"
#include "nsClassHashtable.h"
#include "nsHashKeys.h"
#include "nsRefreshObservers.h"
#include "nsThreadUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/Maybe.h"
#include "mozilla/dom/VisualViewport.h"
#include "mozilla/layers/TransactionIdAllocator.h"
class nsPresContext;
class imgIRequest;
class nsIRunnable;
namespace mozilla {
class AnimationEventDispatcher;
class PendingFullscreenEvent;
class PresShell;
class RefreshDriverTimer;
class Runnable;
namespace layout {
class VsyncChild;
} // namespace layout
} // namespace mozilla
class nsRefreshDriver final : public mozilla::layers::TransactionIdAllocator,
public nsARefreshObserver {
using Document = mozilla::dom::Document;
using TransactionId = mozilla::layers::TransactionId;
using VVPResizeEvent =
mozilla::dom::VisualViewport::VisualViewportResizeEvent;
using VVPScrollEvent =
mozilla::dom::VisualViewport::VisualViewportScrollEvent;
using LogPresShellObserver = mozilla::LogPresShellObserver;
public:
explicit nsRefreshDriver(nsPresContext* aPresContext);
~nsRefreshDriver();
/**
* Methods for testing, exposed via nsIDOMWindowUtils. See
* nsIDOMWindowUtils.advanceTimeAndRefresh for description.
*/
void AdvanceTimeAndRefresh(int64_t aMilliseconds);
void RestoreNormalRefresh();
void DoTick();
bool IsTestControllingRefreshesEnabled() const {
return mTestControllingRefreshes;
}
/**
* Return the time of the most recent refresh. This is intended to be
* used by callers who want to start an animation now and want to know
* what time to consider the start of the animation. (This helps
* ensure that multiple animations started during the same event off
* the main event loop have the same start time.)
*/
mozilla::TimeStamp MostRecentRefresh() const;
/**
* Add / remove refresh observers.
* RemoveRefreshObserver returns true if aObserver was found.
*
* The flush type affects:
* + the order in which the observers are notified (lowest flush
* type to highest, in order registered)
* + (in the future) which observers are suppressed when the display
* doesn't require current position data or isn't currently
* painting, and, correspondingly, which get notified when there
* is a flush during such suppression
* and it must be FlushType::Style, FlushType::Layout, or FlushType::Display.
*
* The refresh driver does NOT own a reference to these observers;
* they must remove themselves before they are destroyed.
*
* The observer will be called even if there is no other activity.
*/
void AddRefreshObserver(nsARefreshObserver* aObserver,
mozilla::FlushType aFlushType);
bool RemoveRefreshObserver(nsARefreshObserver* aObserver,
mozilla::FlushType aFlushType);
/**
* Add / remove an observer wants to know the time when the refresh driver
* updated the most recent refresh time due to its active timer changes.
*/
void AddTimerAdjustmentObserver(nsATimerAdjustmentObserver* aObserver);
void RemoveTimerAdjustmentObserver(nsATimerAdjustmentObserver* aObserver);
void PostVisualViewportResizeEvent(VVPResizeEvent* aResizeEvent);
void DispatchVisualViewportResizeEvents();
void PostScrollEvent(mozilla::Runnable* aScrollEvent, bool aDelayed = false);
void DispatchScrollEvents();
void PostVisualViewportScrollEvent(VVPScrollEvent* aScrollEvent);
void DispatchVisualViewportScrollEvents();
/**
* Add an observer that will be called after each refresh. The caller
* must remove the observer before it is deleted. This does not trigger
* refresh driver ticks.
*/
void AddPostRefreshObserver(nsAPostRefreshObserver* aObserver);
void RemovePostRefreshObserver(nsAPostRefreshObserver* aObserver);
/**
* Add/Remove imgIRequest versions of observers.
*
* These are used for hooking into the refresh driver for
* controlling animated images.
*
* @note The refresh driver owns a reference to these listeners.
*
* @note Technically, imgIRequest objects are not nsARefreshObservers, but
* for controlling animated image repaint events, we subscribe the
* imgIRequests to the nsRefreshDriver for notification of paint events.
*
* @returns whether the operation succeeded, or void in the case of removal.
*/
bool AddImageRequest(imgIRequest* aRequest);
void RemoveImageRequest(imgIRequest* aRequest);
/**
* Add / remove presshells which have pending resize event.
*/
void AddResizeEventFlushObserver(mozilla::PresShell* aPresShell,
bool aDelayed = false) {
MOZ_DIAGNOSTIC_ASSERT(
!mResizeEventFlushObservers.Contains(aPresShell) &&
!mDelayedResizeEventFlushObservers.Contains(aPresShell),
"Double-adding resize event flush observer");
if (aDelayed) {
mDelayedResizeEventFlushObservers.AppendElement(aPresShell);
} else {
mResizeEventFlushObservers.AppendElement(aPresShell);
EnsureTimerStarted();
}
}
void RemoveResizeEventFlushObserver(mozilla::PresShell* aPresShell) {
mResizeEventFlushObservers.RemoveElement(aPresShell);
mDelayedResizeEventFlushObservers.RemoveElement(aPresShell);
}
/**
* Add / remove presshells that we should flush style and layout on
*/
void AddStyleFlushObserver(mozilla::PresShell* aPresShell) {
MOZ_DIAGNOSTIC_ASSERT(!mStyleFlushObservers.Contains(aPresShell),
"Double-adding style flush observer");
LogPresShellObserver::LogDispatch(aPresShell, this);
mStyleFlushObservers.AppendElement(aPresShell);
EnsureTimerStarted();
}
void RemoveStyleFlushObserver(mozilla::PresShell* aPresShell) {
mStyleFlushObservers.RemoveElement(aPresShell);
}
void AddLayoutFlushObserver(mozilla::PresShell* aPresShell) {
MOZ_DIAGNOSTIC_ASSERT(!IsLayoutFlushObserver(aPresShell),
"Double-adding layout flush observer");
LogPresShellObserver::LogDispatch(aPresShell, this);
mLayoutFlushObservers.AppendElement(aPresShell);
EnsureTimerStarted();
}
void RemoveLayoutFlushObserver(mozilla::PresShell* aPresShell) {
mLayoutFlushObservers.RemoveElement(aPresShell);
}
bool IsLayoutFlushObserver(mozilla::PresShell* aPresShell) {
return mLayoutFlushObservers.Contains(aPresShell);
}
/**
* "Early Runner" runnables will be called as the first step when refresh
* driver tick is triggered. Runners shouldn't keep other objects alive,
* since it isn't guaranteed they will ever get called.
*/
void AddEarlyRunner(nsIRunnable* aRunnable) {
mEarlyRunners.AppendElement(aRunnable);
EnsureTimerStarted();
}
/**
* Remember whether our presshell's view manager needs a flush
*/
void ScheduleViewManagerFlush();
void RevokeViewManagerFlush() { mViewManagerFlushIsPending = false; }
bool ViewManagerFlushIsPending() { return mViewManagerFlushIsPending; }
bool HasScheduleFlush() { return mHasScheduleFlush; }
void ClearHasScheduleFlush() { mHasScheduleFlush = false; }
/**
* Add a document for which we have FrameRequestCallbacks
*/
void ScheduleFrameRequestCallbacks(Document* aDocument);
/**
* Remove a document for which we have FrameRequestCallbacks
*/
void RevokeFrameRequestCallbacks(Document* aDocument);
/**
* Queue a new fullscreen event to be dispatched in next tick before
* the style flush
*/
void ScheduleFullscreenEvent(
mozilla::UniquePtr<mozilla::PendingFullscreenEvent> aEvent);
/**
* Cancel all pending fullscreen events scheduled by ScheduleFullscreenEvent
* which targets any node in aDocument.
*/
void CancelPendingFullscreenEvents(Document* aDocument);
/**
* Queue new animation events to dispatch in next tick.
*/
void ScheduleAnimationEventDispatch(
mozilla::AnimationEventDispatcher* aDispatcher) {
NS_ASSERTION(!mAnimationEventFlushObservers.Contains(aDispatcher),
"Double-adding animation event flush observer");
mAnimationEventFlushObservers.AppendElement(aDispatcher);
EnsureTimerStarted();
}
/**
* Cancel all pending animation events associated with |aDispatcher|.
*/
void CancelPendingAnimationEvents(
mozilla::AnimationEventDispatcher* aDispatcher);
/**
* Schedule a frame visibility update "soon", subject to the heuristics and
* throttling we apply to visibility updates.
*/
void ScheduleFrameVisibilityUpdate() { mNeedToRecomputeVisibility = true; }
/**
* Tell the refresh driver that it is done driving refreshes and
* should stop its timer and forget about its pres context. This may
* be called from within a refresh.
*/
void Disconnect();
bool IsFrozen() { return mFreezeCount > 0; }
/**
* Freeze the refresh driver. It should stop delivering future
* refreshes until thawed. Note that the number of calls to Freeze() must
* match the number of calls to Thaw() in order for the refresh driver to
* be un-frozen.
*/
void Freeze();
/**
* Thaw the refresh driver. If the number of calls to Freeze() matches the
* number of calls to this function, the refresh driver should start
* delivering refreshes again.
*/
void Thaw();
/**
* Throttle or unthrottle the refresh driver. This is done if the
* corresponding presshell is hidden or shown.
*/
void SetThrottled(bool aThrottled);
/**
* Return the prescontext we were initialized with
*/
nsPresContext* GetPresContext() const;
/**
* PBackgroundChild actor is created asynchronously in content process.
* We can't create vsync-based timers during PBackground startup. This
* function will be called when PBackgroundChild actor is created. Then we can
* do the pending vsync-based timer creation.
*/
static void PVsyncActorCreated(mozilla::layout::VsyncChild* aVsyncChild);
void CreateVsyncRefreshTimer();
#ifdef DEBUG
/**
* Check whether the given observer is an observer for the given flush type
*/
bool IsRefreshObserver(nsARefreshObserver* aObserver,
mozilla::FlushType aFlushType);
#endif
/**
* Default interval the refresh driver uses, in ms.
*/
static int32_t DefaultInterval();
bool IsInRefresh() { return mInRefresh; }
void SetIsResizeSuppressed() { mResizeSuppressed = true; }
bool IsResizeSuppressed() const { return mResizeSuppressed; }
/**
* The latest value of process-wide jank levels.
*
* For each i, sJankLevels[i] counts the number of times delivery of
* vsync to the main thread has been delayed by at least 2^i
* ms. This data structure has been designed to make it easy to
* determine how much jank has taken place between two instants in
* time.
*
* Return `false` if `aJank` needs to be grown to accomodate the
* data but we didn't have enough memory.
*/
static bool GetJankLevels(mozilla::Vector<uint64_t>& aJank);
// mozilla::layers::TransactionIdAllocator
TransactionId GetTransactionId(bool aThrottle) override;
TransactionId LastTransactionId() const override;
void NotifyTransactionCompleted(TransactionId aTransactionId) override;
void RevokeTransactionId(TransactionId aTransactionId) override;
void ClearPendingTransactions() override;
void ResetInitialTransactionId(TransactionId aTransactionId) override;
mozilla::TimeStamp GetTransactionStart() override;
mozilla::VsyncId GetVsyncId() override;
mozilla::TimeStamp GetVsyncStart() override;
bool IsWaitingForPaint(mozilla::TimeStamp aTime);
// nsARefreshObserver
NS_IMETHOD_(MozExternalRefCountType) AddRef(void) override {
return TransactionIdAllocator::AddRef();
}
NS_IMETHOD_(MozExternalRefCountType) Release(void) override {
return TransactionIdAllocator::Release();
}
virtual void WillRefresh(mozilla::TimeStamp aTime) override;
/**
* Compute the time when the currently active refresh driver timer
* will start its next tick.
*
* Expects a non-null default value that is the upper bound of the
* expected deadline. If the next expected deadline is later than
* the default value, the default value is returned.
*
* If we're animating and we have skipped paints a time in the past
* is returned.
*/
static mozilla::TimeStamp GetIdleDeadlineHint(mozilla::TimeStamp aDefault);
/**
* It returns the expected timestamp of the next tick or nothing if the next
* tick is missed.
*/
static mozilla::Maybe<mozilla::TimeStamp> GetNextTickHint();
static void DispatchIdleRunnableAfterTickUnlessExists(nsIRunnable* aRunnable,
uint32_t aDelay);
static void CancelIdleRunnable(nsIRunnable* aRunnable);
void NotifyDOMContentLoaded();
// Schedule a refresh so that any delayed events will run soon.
void RunDelayedEventsSoon();
void InitializeTimer() {
MOZ_ASSERT(!mActiveTimer);
EnsureTimerStarted();
}
void EnsureIntersectionObservationsUpdateHappens() {
// This is enough to make sure that UpdateIntersectionObservations runs at
// least once. This is presumably the intent of step 5 in [1]:
//
// Schedule an iteration of the event loop in the root's browsing
// context.
//
// Though the wording of it is not quite clear to me...
//
// [1]:
EnsureTimerStarted();
mNeedToUpdateIntersectionObservations = true;
}
enum class TickReasons : uint32_t {
eNone = 0,
eHasObservers = 1 << 0,
eHasImageRequests = 1 << 1,
eNeedsToUpdateIntersectionObservations = 1 << 2,
eHasVisualViewportResizeEvents = 1 << 3,
eHasScrollEvents = 1 << 4,
eHasVisualVieportScrollEvents = 1 << 5,
};
private:
typedef nsTObserverArray<nsARefreshObserver*> ObserverArray;
typedef nsTArray<RefPtr<VVPResizeEvent>> VisualViewportResizeEventArray;
typedef nsTArray<RefPtr<mozilla::Runnable>> ScrollEventArray;
typedef nsTArray<RefPtr<VVPScrollEvent>> VisualViewportScrollEventArray;
typedef nsTHashtable<nsISupportsHashKey> RequestTable;
struct ImageStartData {
ImageStartData() = default;
mozilla::Maybe<mozilla::TimeStamp> mStartTime;
RequestTable mEntries;
};
typedef nsClassHashtable<nsUint32HashKey, ImageStartData> ImageStartTable;
void RunFullscreenSteps();
void DispatchAnimationEvents();
MOZ_CAN_RUN_SCRIPT
void RunFrameRequestCallbacks(mozilla::TimeStamp aNowTime);
void UpdateIntersectionObservations(mozilla::TimeStamp aNowTime);
MOZ_CAN_RUN_SCRIPT_BOUNDARY
void Tick(mozilla::VsyncId aId, mozilla::TimeStamp aNowTime);
enum EnsureTimerStartedFlags {
eNone = 0,
eForceAdjustTimer = 1 << 0,
eAllowTimeToGoBackwards = 1 << 1,
eNeverAdjustTimer = 1 << 2,
};
void EnsureTimerStarted(EnsureTimerStartedFlags aFlags = eNone);
void StopTimer();
bool HasObservers() const;
// Note: This should only be called in the dtor of nsRefreshDriver.
uint32_t ObserverCount() const;
bool HasImageRequests() const;
bool ShouldKeepTimerRunningWhileWaitingForFirstContentfulPaint();
ObserverArray& ArrayFor(mozilla::FlushType aFlushType);
// Trigger a refresh immediately, if haven't been disconnected or frozen.
void DoRefresh();
TickReasons GetReasonsToTick() const;
void AppendTickReasonsToString(TickReasons aReasons, nsACString& aStr) const;
double GetRegularTimerInterval() const;
static double GetThrottledTimerInterval();
static mozilla::TimeDuration GetMinRecomputeVisibilityInterval();
bool HaveFrameRequestCallbacks() const {
return mFrameRequestCallbackDocs.Length() != 0;
}
void FinishedWaitingForTransaction();
mozilla::RefreshDriverTimer* ChooseTimer();
mozilla::RefreshDriverTimer* mActiveTimer;
RefPtr<mozilla::RefreshDriverTimer> mOwnTimer;
mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> mRefreshTimerStartedCause;
// nsPresContext passed in constructor and unset in Disconnect.
mozilla::WeakPtr<nsPresContext> mPresContext;
RefPtr<nsRefreshDriver> mRootRefresh;
// The most recently allocated transaction id.
TransactionId mNextTransactionId;
// This number is mCompletedTransaction + (pending transaction count).
// When we revoke a transaction id, we revert this number (since it's
// no longer outstanding), but not mNextTransactionId (since we don't
// want to reuse the number).
TransactionId mOutstandingTransactionId;
// The most recently completed transaction id.
TransactionId mCompletedTransaction;
uint32_t mFreezeCount;
// How long we wait between ticks for throttled (which generally means
// non-visible) documents registered with a non-throttled refresh driver.
const mozilla::TimeDuration mThrottledFrameRequestInterval;
// How long we wait, at a minimum, before recomputing approximate frame
// visibility information. This is a minimum because, regardless of this
// interval, we only recompute visibility when we've seen a layout or style
// flush since the last time we did it.
const mozilla::TimeDuration mMinRecomputeVisibilityInterval;
mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> mViewManagerFlushCause;
bool mThrottled : 1;
bool mNeedToRecomputeVisibility : 1;
bool mTestControllingRefreshes : 1;
// These two fields are almost the same, the only difference is that
// mViewManagerFlushIsPending gets cleared right before calling
// ProcessPendingUpdates, and mHasScheduleFlush gets cleared right after
// calling ProcessPendingUpdates. It is important that mHasScheduleFlush
// only gets cleared after, but it's not clear if mViewManagerFlushIsPending
// needs to be cleared before.
bool mViewManagerFlushIsPending : 1;
bool mHasScheduleFlush : 1;
bool mInRefresh : 1;
// True if the refresh driver is suspended waiting for transaction
// id's to be returned and shouldn't do any work during Tick().
bool mWaitingForTransaction : 1;
// True if Tick() was skipped because of mWaitingForTransaction and
// we should schedule a new Tick immediately when resumed instead
// of waiting until the next interval.
bool mSkippedPaints : 1;
// True if view managers should delay any resize request until the
// next tick by the refresh driver. This flag will be reset at the
// start of every tick.
bool mResizeSuppressed : 1;
// True if the next tick should notify DOMContentFlushed.
bool mNotifyDOMContentFlushed : 1;
// True if we need to flush in order to update intersection observations in
// all our documents.
bool mNeedToUpdateIntersectionObservations : 1;
// Number of seconds that the refresh driver is blocked waiting for a
// compositor transaction to be completed before we append a note to the gfx
// critical log. The number is doubled every time the threshold is hit.
uint64_t mWarningThreshold;
mozilla::TimeStamp mMostRecentRefresh;
mozilla::TimeStamp mTickStart;
mozilla::VsyncId mTickVsyncId;
mozilla::TimeStamp mTickVsyncTime;
mozilla::TimeStamp mNextThrottledFrameRequestTick;
mozilla::TimeStamp mNextRecomputeVisibilityTick;
mozilla::TimeStamp mBeforeFirstContentfulPaintTimerRunningLimit;
// separate arrays for each flush type we support
ObserverArray mObservers[4];
// These observers should NOT be included in HasObservers() since that method
// is used to determine whether or not to stop the timer, or restore it when
// thawing the refresh driver. On the other hand these observers are intended
// to be called when the timer is re-started and should not influence its
// starting or stopping.
nsTObserverArray<nsATimerAdjustmentObserver*> mTimerAdjustmentObservers;
RequestTable mRequests;
ImageStartTable mStartTable;
AutoTArray<nsCOMPtr<nsIRunnable>, 16> mEarlyRunners;
VisualViewportResizeEventArray mVisualViewportResizeEvents;
ScrollEventArray mScrollEvents;
VisualViewportScrollEventArray mVisualViewportScrollEvents;
// Scroll events on documents that might have events suppressed.
ScrollEventArray mDelayedScrollEvents;
AutoTArray<mozilla::PresShell*, 16> mResizeEventFlushObservers;
AutoTArray<mozilla::PresShell*, 16> mDelayedResizeEventFlushObservers;
AutoTArray<mozilla::PresShell*, 16> mStyleFlushObservers;
AutoTArray<mozilla::PresShell*, 16> mLayoutFlushObservers;
// nsTArray on purpose, because we want to be able to swap.
nsTArray<Document*> mFrameRequestCallbackDocs;
nsTArray<Document*> mThrottledFrameRequestCallbackDocs;
nsTObserverArray<nsAPostRefreshObserver*> mPostRefreshObservers;
nsTArray<mozilla::UniquePtr<mozilla::PendingFullscreenEvent>>
mPendingFullscreenEvents;
AutoTArray<mozilla::AnimationEventDispatcher*, 16>
mAnimationEventFlushObservers;
void BeginRefreshingImages(RequestTable& aEntries,
mozilla::TimeStamp aDesired);
friend class mozilla::RefreshDriverTimer;
static void Shutdown();
// `true` if we are currently in jank-critical mode.
//
// In jank-critical mode, any iteration of the event loop that takes
// more than 16ms to compute will cause an ongoing animation to miss
// frames.
//
// For simplicity, the current implementation assumes that we are
// in jank-critical mode if and only if the vsync driver has at least
// one observer.
static bool IsJankCritical();
};
#endif /* !defined(nsRefreshDriver_h_) */