The Tor Browser: layout/base/nsRefreshDriver.cpp@b8a032363ba2 (annotated)

layout/base/nsRefreshDriver.cpp@b8a032363ba2 (annotated)

layout/base/nsRefreshDriver.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
 /* 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.)
  *
  * Chrome and each tab have their own RefreshDriver, which in turn
  * hooks into one of a few global timer based on RefreshDriverTimer,
  * defined below.  There are two main global timers -- one for active
  * animations, and one for inactive ones.  These are implemented as
  * subclasses of RefreshDriverTimer; see below for a description of
  * their implementations.  In the future, additional timer types may
  * implement things like blocking on vsync.
  */
 #ifdef XP_WIN
 #include <windows.h>
 // mmsystem isn't part of WIN32_LEAN_AND_MEAN, so we have
 // to manually include it
 #include <mmsystem.h>
 #include "WinUtils.h"
 #endif
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/AutoRestore.h"
 #include "nsRefreshDriver.h"
 #include "nsITimer.h"
 #include "nsLayoutUtils.h"
 #include "nsPresContext.h"
 #include "nsComponentManagerUtils.h"
 #include "prlog.h"
 #include "nsAutoPtr.h"
 #include "nsIDocument.h"
 #include "jsapi.h"
 #include "nsContentUtils.h"
 #include "mozilla/Preferences.h"
 #include "nsViewManager.h"
 #include "GeckoProfiler.h"
 #include "nsNPAPIPluginInstance.h"
 #include "nsPerformance.h"
 #include "mozilla/dom/WindowBinding.h"
 #include "RestyleManager.h"
 #include "Layers.h"
 #include "imgIContainer.h"
 #include "nsIFrameRequestCallback.h"
 #include "mozilla/dom/ScriptSettings.h"
 using namespace mozilla;
 using namespace mozilla::widget;
 #ifdef PR_LOGGING
 static PRLogModuleInfo *gLog = nullptr;
 #define LOG(...) PR_LOG(gLog, PR_LOG_NOTICE, (__VA_ARGS__))
 #else
 #define LOG(...) do { } while(0)
 #endif
 #define DEFAULT_FRAME_RATE 60
 #define DEFAULT_THROTTLED_FRAME_RATE 1
 // after 10 minutes, stop firing off inactive timers
 #define DEFAULT_INACTIVE_TIMER_DISABLE_SECONDS 600
 namespace mozilla {
 /*
  * The base class for all global refresh driver timers.  It takes care
  * of managing the list of refresh drivers attached to them and
  * provides interfaces for querying/setting the rate and actually
  * running a timer 'Tick'.  Subclasses must implement StartTimer(),
  * StopTimer(), and ScheduleNextTick() -- the first two just
  * start/stop whatever timer mechanism is in use, and ScheduleNextTick
  * is called at the start of the Tick() implementation to set a time
  * for the next tick.
  */
 class RefreshDriverTimer {
 public:
   /*
    * aRate -- the delay, in milliseconds, requested between timer firings
    */
   RefreshDriverTimer(double aRate)
   {
     SetRate(aRate);
   }
   virtual ~RefreshDriverTimer()
   {
     NS_ASSERTION(mRefreshDrivers.Length() == 0, "Should have removed all refresh drivers from here by now!");
   }
   virtual void AddRefreshDriver(nsRefreshDriver* aDriver)
   {
     LOG("[%p] AddRefreshDriver %p", this, aDriver);
     NS_ASSERTION(!mRefreshDrivers.Contains(aDriver), "AddRefreshDriver for a refresh driver that's already in the list!");
     mRefreshDrivers.AppendElement(aDriver);
     if (mRefreshDrivers.Length() == 1) {
       StartTimer();
     }
   }
   virtual void RemoveRefreshDriver(nsRefreshDriver* aDriver)
   {
     LOG("[%p] RemoveRefreshDriver %p", this, aDriver);
     NS_ASSERTION(mRefreshDrivers.Contains(aDriver), "RemoveRefreshDriver for a refresh driver that's not in the list!");
     mRefreshDrivers.RemoveElement(aDriver);
     if (mRefreshDrivers.Length() == 0) {
       StopTimer();
     }
   }
   double GetRate() const
   {
     return mRateMilliseconds;
   }
   // will take effect at next timer tick
   virtual void SetRate(double aNewRate)
   {
     mRateMilliseconds = aNewRate;
     mRateDuration = TimeDuration::FromMilliseconds(mRateMilliseconds);
   }
   TimeStamp MostRecentRefresh() const { return mLastFireTime; }
   int64_t MostRecentRefreshEpochTime() const { return mLastFireEpoch; }
 protected:
   virtual void StartTimer() = 0;
   virtual void StopTimer() = 0;
   virtual void ScheduleNextTick(TimeStamp aNowTime) = 0;
   /*
    * Actually runs a tick, poking all the attached RefreshDrivers.
    * Grabs the "now" time via JS_Now and TimeStamp::Now().
    */
   void Tick()
   {
     int64_t jsnow = JS_Now();
     TimeStamp now = TimeStamp::Now();
     ScheduleNextTick(now);
     mLastFireEpoch = jsnow;
     mLastFireTime = now;
     LOG("[%p] ticking drivers...", this);
     nsTArray<nsRefPtr<nsRefreshDriver> > drivers(mRefreshDrivers);
     for (size_t i = 0; i < drivers.Length(); ++i) {
       // don't poke this driver if it's in test mode
       if (drivers[i]->IsTestControllingRefreshesEnabled()) {
         continue;
       }
       TickDriver(drivers[i], jsnow, now);
     }
     LOG("[%p] done.", this);
   }
   static void TickDriver(nsRefreshDriver* driver, int64_t jsnow, TimeStamp now)
   {
     LOG(">> TickDriver: %p (jsnow: %lld)", driver, jsnow);
     driver->Tick(jsnow, now);
   }
   double mRateMilliseconds;
   TimeDuration mRateDuration;
   int64_t mLastFireEpoch;
   TimeStamp mLastFireTime;
   TimeStamp mTargetTime;
   nsTArray<nsRefPtr<nsRefreshDriver> > mRefreshDrivers;
   // useful callback for nsITimer-based derived classes, here
   // bacause of c++ protected shenanigans
   static void TimerTick(nsITimer* aTimer, void* aClosure)
   {
     RefreshDriverTimer *timer = static_cast<RefreshDriverTimer*>(aClosure);
     timer->Tick();
   }
 };
 /*
  * A RefreshDriverTimer that uses a nsITimer as the underlying timer.  Note that
  * this is a ONE_SHOT timer, not a repeating one!  Subclasses are expected to
  * implement ScheduleNextTick and intelligently calculate the next time to tick,
  * and to reset mTimer.  Using a repeating nsITimer gets us into a lot of pain
  * with its attempt at intelligent slack removal and such, so we don't do it.
  */
 class SimpleTimerBasedRefreshDriverTimer :
     public RefreshDriverTimer
 {
 public:
   SimpleTimerBasedRefreshDriverTimer(double aRate)
     : RefreshDriverTimer(aRate)
   {
     mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
   }
   virtual ~SimpleTimerBasedRefreshDriverTimer()
   {
     StopTimer();
   }
 protected:
   virtual void StartTimer()
   {
     // pretend we just fired, and we schedule the next tick normally
     mLastFireEpoch = JS_Now();
     mLastFireTime = TimeStamp::Now();
     mTargetTime = mLastFireTime + mRateDuration;
     uint32_t delay = static_cast<uint32_t>(mRateMilliseconds);
     mTimer->InitWithFuncCallback(TimerTick, this, delay, nsITimer::TYPE_ONE_SHOT);
   }
   virtual void StopTimer()
   {
     mTimer->Cancel();
   }
   nsRefPtr<nsITimer> mTimer;
 };
 /*
  * PreciseRefreshDriverTimer schedules ticks based on the current time
  * and when the next tick -should- be sent if we were hitting our
  * rate.  It always schedules ticks on multiples of aRate -- meaning that
  * if some execution takes longer than an alloted slot, the next tick
  * will be delayed instead of triggering instantly.  This might not be
  * desired -- there's an #if 0'd block below that we could put behind
  * a pref to control this behaviour.
  */
 class PreciseRefreshDriverTimer :
     public SimpleTimerBasedRefreshDriverTimer
 {
 public:
   PreciseRefreshDriverTimer(double aRate)
     : SimpleTimerBasedRefreshDriverTimer(aRate)
   {
   }
 protected:
   virtual void ScheduleNextTick(TimeStamp aNowTime)
   {
     // The number of (whole) elapsed intervals between the last target
     // time and the actual time.  We want to truncate the double down
     // to an int number of intervals.
     int numElapsedIntervals = static_cast<int>((aNowTime - mTargetTime) / mRateDuration);
     if (numElapsedIntervals < 0) {
       // It's possible that numElapsedIntervals is negative (e.g. timer compensation
       // may result in (aNowTime - mTargetTime) < -1.0/mRateDuration, which will result in
       // negative numElapsedIntervals), so make sure we don't target the same timestamp.
       numElapsedIntervals = 0;
     }
     // the last "tick" that may or may not have been actually sent was
     // at this time.  For example, if the rate is 15ms, the target
     // time is 200ms, and it's now 225ms, the last effective tick
     // would have been at 215ms.  The next one should then be
     // scheduled for 5 ms from now.
     //
     // We then add another mRateDuration to find the next tick target.
     TimeStamp newTarget = mTargetTime + mRateDuration * (numElapsedIntervals + 1);
     // the amount of (integer) ms until the next time we should tick
     uint32_t delay = static_cast<uint32_t>((newTarget - aNowTime).ToMilliseconds());
     // Without this block, we'll always schedule on interval ticks;
     // with it, we'll schedule immediately if we missed our tick target
     // last time.
 #if 0
     if (numElapsedIntervals > 0) {
       // we're late, so reset
       newTarget = aNowTime;
       delay = 0;
     }
 #endif
     // log info & lateness
     LOG("[%p] precise timer last tick late by %f ms, next tick in %d ms",
         this,
         (aNowTime - mTargetTime).ToMilliseconds(),
         delay);
     // then schedule the timer
     LOG("[%p] scheduling callback for %d ms (2)", this, delay);
     mTimer->InitWithFuncCallback(TimerTick, this, delay, nsITimer::TYPE_ONE_SHOT);
     mTargetTime = newTarget;
   }
 };
 #ifdef XP_WIN
 /*
  * Uses vsync timing on windows with DWM. Falls back dynamically to fixed rate if required.
  */
 class PreciseRefreshDriverTimerWindowsDwmVsync :
   public PreciseRefreshDriverTimer
 {
 public:
   // Checks if the vsync API is accessible.
   static bool IsSupported()
   {
     return WinUtils::dwmGetCompositionTimingInfoPtr != nullptr;
   }
   PreciseRefreshDriverTimerWindowsDwmVsync(double aRate, bool aPreferHwTiming = false)
     : PreciseRefreshDriverTimer(aRate)
     , mPreferHwTiming(aPreferHwTiming)
   {
   }
 protected:
   // Indicates we should try to adjust to the HW's timing (get rate from the OS or use vsync)
   // This is typically true if the default refresh-rate value was not modified by the user.
   bool mPreferHwTiming;
   nsresult GetVBlankInfo(mozilla::TimeStamp &aLastVBlank, mozilla::TimeDuration &aInterval)
   {
     MOZ_ASSERT(WinUtils::dwmGetCompositionTimingInfoPtr,
                "DwmGetCompositionTimingInfoPtr is unavailable (windows vsync)");
     DWM_TIMING_INFO timingInfo;
     timingInfo.cbSize = sizeof(DWM_TIMING_INFO);
     HRESULT hr = WinUtils::dwmGetCompositionTimingInfoPtr(0, &timingInfo); // For the desktop window instead of a specific one.
     if (FAILED(hr)) {
       // This happens first time this is called.
       return NS_ERROR_NOT_INITIALIZED;
     }
     LARGE_INTEGER time, freq;
     ::QueryPerformanceCounter(&time);
     ::QueryPerformanceFrequency(&freq);
     aLastVBlank = TimeStamp::Now();
     double secondsPassed = double(time.QuadPart - timingInfo.qpcVBlank) / double(freq.QuadPart);
     aLastVBlank -= TimeDuration::FromSeconds(secondsPassed);
     aInterval = TimeDuration::FromSeconds(double(timingInfo.qpcRefreshPeriod) / double(freq.QuadPart));
     return NS_OK;
   }
   virtual void ScheduleNextTick(TimeStamp aNowTime)
   {
     static const TimeDuration kMinSaneInterval = TimeDuration::FromMilliseconds(3); // 330Hz
     static const TimeDuration kMaxSaneInterval = TimeDuration::FromMilliseconds(44); // 23Hz
     static const TimeDuration kNegativeMaxSaneInterval = TimeDuration::FromMilliseconds(-44); // Saves conversions for abs interval
     TimeStamp lastVblank;
     TimeDuration vblankInterval;
     if (!mPreferHwTiming ||
         NS_OK != GetVBlankInfo(lastVblank, vblankInterval) ||
         vblankInterval > kMaxSaneInterval ||
         vblankInterval < kMinSaneInterval ||
         (aNowTime - lastVblank) > kMaxSaneInterval ||
         (aNowTime - lastVblank) < kNegativeMaxSaneInterval) {
       // Use the default timing without vsync
       PreciseRefreshDriverTimer::ScheduleNextTick(aNowTime);
       return;
     }
     TimeStamp newTarget = lastVblank + vblankInterval; // Base target
     // However, timer callback might return early (or late, but that wouldn't bother us), and vblankInterval
     // appears to be slightly (~1%) different on each call (probably the OS measuring recent actual interval[s])
     // and since we don't want to re-target the same vsync, we keep advancing in vblank intervals until we find the
     // next safe target (next vsync, but not within 10% interval of previous target).
     // This is typically 0 or 1 iteration:
     // If we're too early, next vsync would be the one we've already targeted (1 iteration).
     // If the timer returned late, no iteration will be required.
     const double kSameVsyncThreshold = 0.1;
     while (newTarget <= mTargetTime + vblankInterval.MultDouble(kSameVsyncThreshold)) {
       newTarget += vblankInterval;
     }
     // To make sure we always hit the same "side" of the signal:
     // round the delay up (by adding 1, since we later floor) and add a little (10% by default).
     // Note that newTarget doesn't change (and is the next vblank) as a reference when we're back.
     static const double kDefaultPhaseShiftPercent = 10;
     static const double phaseShiftFactor = 0.01 *
       (Preferences::GetInt("layout.frame_rate.vsync.phasePercentage", kDefaultPhaseShiftPercent) % 100);
     double phaseDelay = 1.0 + vblankInterval.ToMilliseconds() * phaseShiftFactor;
     // ms until the next time we should tick
     double delayMs = (newTarget - aNowTime).ToMilliseconds() + phaseDelay;
     // Make sure the delay is never negative.
     uint32_t delay = static_cast<uint32_t>(delayMs < 0 ? 0 : delayMs);
     // log info & lateness
     LOG("[%p] precise dwm-vsync timer last tick late by %f ms, next tick in %d ms",
         this,
         (aNowTime - mTargetTime).ToMilliseconds(),
         delay);
     // then schedule the timer
     LOG("[%p] scheduling callback for %d ms (2)", this, delay);
     mTimer->InitWithFuncCallback(TimerTick, this, delay, nsITimer::TYPE_ONE_SHOT);
     mTargetTime = newTarget;
   }
 };
 #endif
 /*
  * A RefreshDriverTimer for inactive documents.  When a new refresh driver is
  * added, the rate is reset to the base (normally 1s/1fps).  Every time
  * it ticks, a single refresh driver is poked.  Once they have all been poked,
  * the duration between ticks doubles, up to mDisableAfterMilliseconds.  At that point,
  * the timer is quiet and doesn't tick (until something is added to it again).
  *
  * When a timer is removed, there is a possibility of another timer
  * being skipped for one cycle.  We could avoid this by adjusting
  * mNextDriverIndex in RemoveRefreshDriver, but there's little need to
  * add that complexity.  All we want is for inactive drivers to tick
  * at some point, but we don't care too much about how often.
  */
 class InactiveRefreshDriverTimer :
     public RefreshDriverTimer
 {
 public:
   InactiveRefreshDriverTimer(double aRate)
     : RefreshDriverTimer(aRate),
       mNextTickDuration(aRate),
       mDisableAfterMilliseconds(-1.0),
       mNextDriverIndex(0)
   {
     mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
   }
   InactiveRefreshDriverTimer(double aRate, double aDisableAfterMilliseconds)
     : RefreshDriverTimer(aRate),
       mNextTickDuration(aRate),
       mDisableAfterMilliseconds(aDisableAfterMilliseconds),
       mNextDriverIndex(0)
   {
     mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
   }
   virtual void AddRefreshDriver(nsRefreshDriver* aDriver)
   {
     RefreshDriverTimer::AddRefreshDriver(aDriver);
     LOG("[%p] inactive timer got new refresh driver %p, resetting rate",
         this, aDriver);
     // reset the timer, and start with the newly added one next time.
     mNextTickDuration = mRateMilliseconds;
     // we don't really have to start with the newly added one, but we may as well
     // not tick the old ones at the fastest rate any more than we need to.
     mNextDriverIndex = mRefreshDrivers.Length() - 1;
     StopTimer();
     StartTimer();
   }
 protected:
   virtual void StartTimer()
   {
     mLastFireEpoch = JS_Now();
     mLastFireTime = TimeStamp::Now();
     mTargetTime = mLastFireTime + mRateDuration;
     uint32_t delay = static_cast<uint32_t>(mRateMilliseconds);
     mTimer->InitWithFuncCallback(TimerTickOne, this, delay, nsITimer::TYPE_ONE_SHOT);
   }
   virtual void StopTimer()
   {
     mTimer->Cancel();
   }
   virtual void ScheduleNextTick(TimeStamp aNowTime)
   {
     if (mDisableAfterMilliseconds > 0.0 &&
         mNextTickDuration > mDisableAfterMilliseconds)
     {
       // We hit the time after which we should disable
       // inactive window refreshes; don't schedule anything
       // until we get kicked by an AddRefreshDriver call.
       return;
     }
     // double the next tick time if we've already gone through all of them once
     if (mNextDriverIndex >= mRefreshDrivers.Length()) {
       mNextTickDuration *= 2.0;
       mNextDriverIndex = 0;
     }
     // this doesn't need to be precise; do a simple schedule
     uint32_t delay = static_cast<uint32_t>(mNextTickDuration);
     mTimer->InitWithFuncCallback(TimerTickOne, this, delay, nsITimer::TYPE_ONE_SHOT);
     LOG("[%p] inactive timer next tick in %f ms [index %d/%d]", this, mNextTickDuration,
         mNextDriverIndex, mRefreshDrivers.Length());
   }
   /* Runs just one driver's tick. */
   void TickOne()
   {
     int64_t jsnow = JS_Now();
     TimeStamp now = TimeStamp::Now();
     ScheduleNextTick(now);
     mLastFireEpoch = jsnow;
     mLastFireTime = now;
     nsTArray<nsRefPtr<nsRefreshDriver> > drivers(mRefreshDrivers);
     if (mNextDriverIndex < drivers.Length() &&
         !drivers[mNextDriverIndex]->IsTestControllingRefreshesEnabled())
     {
       TickDriver(drivers[mNextDriverIndex], jsnow, now);
     }
     mNextDriverIndex++;
   }
   static void TimerTickOne(nsITimer* aTimer, void* aClosure)
   {
     InactiveRefreshDriverTimer *timer = static_cast<InactiveRefreshDriverTimer*>(aClosure);
     timer->TickOne();
   }
   nsRefPtr<nsITimer> mTimer;
   double mNextTickDuration;
   double mDisableAfterMilliseconds;
   uint32_t mNextDriverIndex;
 };
 } // namespace mozilla
 static uint32_t
 GetFirstFrameDelay(imgIRequest* req)
 {
   nsCOMPtr<imgIContainer> container;
   if (NS_FAILED(req->GetImage(getter_AddRefs(container))) || !container) {
     return 0;
   }
   // If this image isn't animated, there isn't a first frame delay.
   int32_t delay = container->GetFirstFrameDelay();
   if (delay < 0)
     return 0;
   return static_cast<uint32_t>(delay);
 }
 static PreciseRefreshDriverTimer *sRegularRateTimer = nullptr;
 static InactiveRefreshDriverTimer *sThrottledRateTimer = nullptr;
 #ifdef XP_WIN
 static int32_t sHighPrecisionTimerRequests = 0;
 // a bare pointer to avoid introducing a static constructor
 static nsITimer *sDisableHighPrecisionTimersTimer = nullptr;
 #endif
 /* static */ void
 nsRefreshDriver::InitializeStatics()
 {
 #ifdef PR_LOGGING
   if (!gLog) {
     gLog = PR_NewLogModule("nsRefreshDriver");
   }
 #endif
 }
 /* static */ void
 nsRefreshDriver::Shutdown()
 {
   // clean up our timers
   delete sRegularRateTimer;
   delete sThrottledRateTimer;
   sRegularRateTimer = nullptr;
   sThrottledRateTimer = nullptr;
 #ifdef XP_WIN
   if (sDisableHighPrecisionTimersTimer) {
     sDisableHighPrecisionTimersTimer->Cancel();
     NS_RELEASE(sDisableHighPrecisionTimersTimer);
     timeEndPeriod(1);
   } else if (sHighPrecisionTimerRequests) {
     timeEndPeriod(1);
   }
 #endif
 }
 /* static */ int32_t
 nsRefreshDriver::DefaultInterval()
 {
   return NSToIntRound(1000.0 / DEFAULT_FRAME_RATE);
 }
 // Compute the interval to use for the refresh driver timer, in milliseconds.
 // outIsDefault indicates that rate was not explicitly set by the user
 // so we might choose other, more appropriate rates (e.g. vsync, etc)
 // layout.frame_rate=0 indicates "ASAP mode".
 // In ASAP mode rendering is iterated as fast as possible (typically for stress testing).
 // A target rate of 10k is used internally instead of special-handling 0.
 // Backends which block on swap/present/etc should try to not block
 // when layout.frame_rate=0 - to comply with "ASAP" as much as possible.
 double
 nsRefreshDriver::GetRegularTimerInterval(bool *outIsDefault) const
 {
   int32_t rate = Preferences::GetInt("layout.frame_rate", -1);
   if (rate < 0) {
     rate = DEFAULT_FRAME_RATE;
     if (outIsDefault) {
       *outIsDefault = true;
     }
   } else {
     if (outIsDefault) {
       *outIsDefault = false;
     }
   }
   if (rate == 0) {
     rate = 10000;
   }
   return 1000.0 / rate;
 }
 double
 nsRefreshDriver::GetThrottledTimerInterval() const
 {
   int32_t rate = Preferences::GetInt("layout.throttled_frame_rate", -1);
   if (rate <= 0) {
     rate = DEFAULT_THROTTLED_FRAME_RATE;
   }
   return 1000.0 / rate;
 }
 double
 nsRefreshDriver::GetRefreshTimerInterval() const
 {
   return mThrottled ? GetThrottledTimerInterval() : GetRegularTimerInterval();
 }
 RefreshDriverTimer*
 nsRefreshDriver::ChooseTimer() const
 {
   if (mThrottled) {
     if (!sThrottledRateTimer)
       sThrottledRateTimer = new InactiveRefreshDriverTimer(GetThrottledTimerInterval(),
                                                            DEFAULT_INACTIVE_TIMER_DISABLE_SECONDS * 1000.0);
     return sThrottledRateTimer;
   }
   if (!sRegularRateTimer) {
     bool isDefault = true;
     double rate = GetRegularTimerInterval(&isDefault);
 #ifdef XP_WIN
     if (PreciseRefreshDriverTimerWindowsDwmVsync::IsSupported()) {
       sRegularRateTimer = new PreciseRefreshDriverTimerWindowsDwmVsync(rate, isDefault);
     }
 #endif
     if (!sRegularRateTimer) {
       sRegularRateTimer = new PreciseRefreshDriverTimer(rate);
     }
   }
   return sRegularRateTimer;
 }
 nsRefreshDriver::nsRefreshDriver(nsPresContext* aPresContext)
   : mActiveTimer(nullptr),
     mPresContext(aPresContext),
     mFreezeCount(0),
     mThrottled(false),
     mTestControllingRefreshes(false),
     mViewManagerFlushIsPending(false),
     mRequestedHighPrecision(false),
     mInRefresh(false)
 {
   mMostRecentRefreshEpochTime = JS_Now();
   mMostRecentRefresh = TimeStamp::Now();
 }
 nsRefreshDriver::~nsRefreshDriver()
 {
   NS_ABORT_IF_FALSE(ObserverCount() == 0,
                     "observers should have unregistered");
   NS_ABORT_IF_FALSE(!mActiveTimer, "timer should be gone");
   for (uint32_t i = 0; i < mPresShellsToInvalidateIfHidden.Length(); i++) {
     mPresShellsToInvalidateIfHidden[i]->InvalidatePresShellIfHidden();
   }
   mPresShellsToInvalidateIfHidden.Clear();
 }
 // Method for testing.  See nsIDOMWindowUtils.advanceTimeAndRefresh
 // for description.
 void
 nsRefreshDriver::AdvanceTimeAndRefresh(int64_t aMilliseconds)
 {
   // ensure that we're removed from our driver
   StopTimer();
   if (!mTestControllingRefreshes) {
     mMostRecentRefreshEpochTime = JS_Now();
     mMostRecentRefresh = TimeStamp::Now();
     mTestControllingRefreshes = true;
   }
   mMostRecentRefreshEpochTime += aMilliseconds * 1000;
   mMostRecentRefresh += TimeDuration::FromMilliseconds((double) aMilliseconds);
   mozilla::dom::AutoNoJSAPI nojsapi;
   DoTick();
 }
 void
 nsRefreshDriver::RestoreNormalRefresh()
 {
   mTestControllingRefreshes = false;
   EnsureTimerStarted(false);
 }
 TimeStamp
 nsRefreshDriver::MostRecentRefresh() const
 {
   const_cast<nsRefreshDriver*>(this)->EnsureTimerStarted(false);
   return mMostRecentRefresh;
 }
 int64_t
 nsRefreshDriver::MostRecentRefreshEpochTime() const
 {
   const_cast<nsRefreshDriver*>(this)->EnsureTimerStarted(false);
   return mMostRecentRefreshEpochTime;
 }
 bool
 nsRefreshDriver::AddRefreshObserver(nsARefreshObserver* aObserver,
                                     mozFlushType aFlushType)
 {
   ObserverArray& array = ArrayFor(aFlushType);
   bool success = array.AppendElement(aObserver) != nullptr;
   EnsureTimerStarted(false);
   return success;
 }
 bool
 nsRefreshDriver::RemoveRefreshObserver(nsARefreshObserver* aObserver,
                                        mozFlushType aFlushType)
 {
   ObserverArray& array = ArrayFor(aFlushType);
   return array.RemoveElement(aObserver);
 }
 void
 nsRefreshDriver::AddPostRefreshObserver(nsAPostRefreshObserver* aObserver)
 {
   mPostRefreshObservers.AppendElement(aObserver);
 }
 void
 nsRefreshDriver::RemovePostRefreshObserver(nsAPostRefreshObserver* aObserver)
 {
   mPostRefreshObservers.RemoveElement(aObserver);
 }
 bool
 nsRefreshDriver::AddImageRequest(imgIRequest* aRequest)
 {
   uint32_t delay = GetFirstFrameDelay(aRequest);
   if (delay == 0) {
     if (!mRequests.PutEntry(aRequest)) {
       return false;
     }
   } else {
     ImageStartData* start = mStartTable.Get(delay);
     if (!start) {
       start = new ImageStartData();
       mStartTable.Put(delay, start);
     }
     start->mEntries.PutEntry(aRequest);
   }
   EnsureTimerStarted(false);
   return true;
 }
 void
 nsRefreshDriver::RemoveImageRequest(imgIRequest* aRequest)
 {
   // Try to remove from both places, just in case, because we can't tell
   // whether RemoveEntry() succeeds.
   mRequests.RemoveEntry(aRequest);
   uint32_t delay = GetFirstFrameDelay(aRequest);
   if (delay != 0) {
     ImageStartData* start = mStartTable.Get(delay);
     if (start) {
       start->mEntries.RemoveEntry(aRequest);
     }
   }
 }
 void
 nsRefreshDriver::EnsureTimerStarted(bool aAdjustingTimer)
 {
   if (mTestControllingRefreshes)
     return;
   // will it already fire, and no other changes needed?
   if (mActiveTimer && !aAdjustingTimer)
     return;
   if (IsFrozen() || !mPresContext) {
     // If we don't want to start it now, or we've been disconnected.
     StopTimer();
     return;
   }
   // We got here because we're either adjusting the time *or* we're
   // starting it for the first time.  Add to the right timer,
   // prehaps removing it from a previously-set one.
   RefreshDriverTimer *newTimer = ChooseTimer();
   if (newTimer != mActiveTimer) {
     if (mActiveTimer)
       mActiveTimer->RemoveRefreshDriver(this);
     mActiveTimer = newTimer;
     mActiveTimer->AddRefreshDriver(this);
   }
   mMostRecentRefresh = mActiveTimer->MostRecentRefresh();
   mMostRecentRefreshEpochTime = mActiveTimer->MostRecentRefreshEpochTime();
 }
 void
 nsRefreshDriver::StopTimer()
 {
   if (!mActiveTimer)
     return;
   mActiveTimer->RemoveRefreshDriver(this);
   mActiveTimer = nullptr;
   if (mRequestedHighPrecision) {
     SetHighPrecisionTimersEnabled(false);
   }
 }
 #ifdef XP_WIN
 static void
 DisableHighPrecisionTimersCallback(nsITimer *aTimer, void *aClosure)
 {
   timeEndPeriod(1);
   NS_RELEASE(sDisableHighPrecisionTimersTimer);
 }
 #endif
 void
 nsRefreshDriver::ConfigureHighPrecision()
 {
   bool haveFrameRequestCallbacks = mFrameRequestCallbackDocs.Length() > 0;
   // if the only change that's needed is that we need high precision,
   // then just set that
   if (!mThrottled && !mRequestedHighPrecision && haveFrameRequestCallbacks) {
     SetHighPrecisionTimersEnabled(true);
   } else if (mRequestedHighPrecision && !haveFrameRequestCallbacks) {
     SetHighPrecisionTimersEnabled(false);
   }
 }
 void
 nsRefreshDriver::SetHighPrecisionTimersEnabled(bool aEnable)
 {
   LOG("[%p] SetHighPrecisionTimersEnabled (%s)", this, aEnable ? "true" : "false");
   if (aEnable) {
     NS_ASSERTION(!mRequestedHighPrecision, "SetHighPrecisionTimersEnabled(true) called when already requested!");
 #ifdef XP_WIN
     if (++sHighPrecisionTimerRequests == 1) {
       // If we had a timer scheduled to disable it, that means that it's already
       // enabled; just cancel the timer.  Otherwise, really enable it.
       if (sDisableHighPrecisionTimersTimer) {
         sDisableHighPrecisionTimersTimer->Cancel();
         NS_RELEASE(sDisableHighPrecisionTimersTimer);
       } else {
         timeBeginPeriod(1);
       }
     }
 #endif
     mRequestedHighPrecision = true;
   } else {
     NS_ASSERTION(mRequestedHighPrecision, "SetHighPrecisionTimersEnabled(false) called when not requested!");
 #ifdef XP_WIN
     if (--sHighPrecisionTimerRequests == 0) {
       // Don't jerk us around between high precision and low precision
       // timers; instead, only allow leaving high precision timers
       // after 90 seconds.  This is arbitrary, but hopefully good
       // enough.
       NS_ASSERTION(!sDisableHighPrecisionTimersTimer, "We shouldn't have an outstanding disable-high-precision timer !");
       nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID);
       if (timer) {
         timer.forget(&sDisableHighPrecisionTimersTimer);
         sDisableHighPrecisionTimersTimer->InitWithFuncCallback(DisableHighPrecisionTimersCallback,
                                                                nullptr,
 * 1000,
                                                                nsITimer::TYPE_ONE_SHOT);
       } else {
         // might happen if we're shutting down XPCOM; just drop the time period down
         // immediately
         timeEndPeriod(1);
       }
     }
 #endif
     mRequestedHighPrecision = false;
   }
 }
 uint32_t
 nsRefreshDriver::ObserverCount() const
 {
   uint32_t sum = 0;
   for (uint32_t i = 0; i < ArrayLength(mObservers); ++i) {
     sum += mObservers[i].Length();
   }
   // Even while throttled, we need to process layout and style changes.  Style
   // changes can trigger transitions which fire events when they complete, and
   // layout changes can affect media queries on child documents, triggering
   // style changes, etc.
   sum += mStyleFlushObservers.Length();
   sum += mLayoutFlushObservers.Length();
   sum += mFrameRequestCallbackDocs.Length();
   sum += mViewManagerFlushIsPending;
   return sum;
 }
 /* static */ PLDHashOperator
 nsRefreshDriver::StartTableRequestCounter(const uint32_t& aKey,
                                           ImageStartData* aEntry,
                                           void* aUserArg)
 {
   uint32_t *count = static_cast<uint32_t*>(aUserArg);
   *count += aEntry->mEntries.Count();
   return PL_DHASH_NEXT;
 }
 uint32_t
 nsRefreshDriver::ImageRequestCount() const
 {
   uint32_t count = 0;
   mStartTable.EnumerateRead(nsRefreshDriver::StartTableRequestCounter, &count);
   return count + mRequests.Count();
 }
 nsRefreshDriver::ObserverArray&
 nsRefreshDriver::ArrayFor(mozFlushType aFlushType)
 {
   switch (aFlushType) {
     case Flush_Style:
       return mObservers[0];
     case Flush_Layout:
       return mObservers[1];
     case Flush_Display:
       return mObservers[2];
     default:
       NS_ABORT_IF_FALSE(false, "bad flush type");
       return *static_cast<ObserverArray*>(nullptr);
   }
 }
 /*
  * nsISupports implementation
  */
 NS_IMPL_ISUPPORTS(nsRefreshDriver, nsISupports)
 /*
  * nsITimerCallback implementation
  */
 void
 nsRefreshDriver::DoTick()
 {
   NS_PRECONDITION(!IsFrozen(), "Why are we notified while frozen?");
   NS_PRECONDITION(mPresContext, "Why are we notified after disconnection?");
   NS_PRECONDITION(!nsContentUtils::GetCurrentJSContext(),
                   "Shouldn't have a JSContext on the stack");
   if (mTestControllingRefreshes) {
     Tick(mMostRecentRefreshEpochTime, mMostRecentRefresh);
   } else {
     Tick(JS_Now(), TimeStamp::Now());
   }
 }
 struct DocumentFrameCallbacks {
   DocumentFrameCallbacks(nsIDocument* aDocument) :
     mDocument(aDocument)
   {}
   nsCOMPtr<nsIDocument> mDocument;
   nsIDocument::FrameRequestCallbackList mCallbacks;
 };
 void
 nsRefreshDriver::Tick(int64_t aNowEpoch, TimeStamp aNowTime)
 {
   NS_PRECONDITION(!nsContentUtils::GetCurrentJSContext(),
                   "Shouldn't have a JSContext on the stack");
   if (nsNPAPIPluginInstance::InPluginCallUnsafeForReentry()) {
     NS_ERROR("Refresh driver should not run during plugin call!");
     // Try to survive this by just ignoring the refresh tick.
     return;
   }
   PROFILER_LABEL("nsRefreshDriver", "Tick");
   // We're either frozen or we were disconnected (likely in the middle
   // of a tick iteration).  Just do nothing here, since our
   // prescontext went away.
   if (IsFrozen() || !mPresContext) {
     return;
   }
   TimeStamp previousRefresh = mMostRecentRefresh;
   mMostRecentRefresh = aNowTime;
   mMostRecentRefreshEpochTime = aNowEpoch;
   nsCOMPtr<nsIPresShell> presShell = mPresContext->GetPresShell();
   if (!presShell || (ObserverCount() == 0 && ImageRequestCount() == 0)) {
     // Things are being destroyed, or we no longer have any observers.
     // We don't want to stop the timer when observers are initially
     // removed, because sometimes observers can be added and removed
     // often depending on what other things are going on and in that
     // situation we don't want to thrash our timer.  So instead we
     // wait until we get a Notify() call when we have no observers
     // before stopping the timer.
     StopTimer();
     return;
   }
   profiler_tracing("Paint", "RD", TRACING_INTERVAL_START);
   AutoRestore<bool> restoreInRefresh(mInRefresh);
   mInRefresh = true;
   /*
    * The timer holds a reference to |this| while calling |Notify|.
    * However, implementations of |WillRefresh| are permitted to destroy
    * the pres context, which will cause our |mPresContext| to become
    * null.  If this happens, we must stop notifying observers.
    */
   for (uint32_t i = 0; i < ArrayLength(mObservers); ++i) {
     ObserverArray::EndLimitedIterator etor(mObservers[i]);
     while (etor.HasMore()) {
       nsRefPtr<nsARefreshObserver> obs = etor.GetNext();
       obs->WillRefresh(aNowTime);
       if (!mPresContext || !mPresContext->GetPresShell()) {
         StopTimer();
         profiler_tracing("Paint", "RD", TRACING_INTERVAL_END);
         return;
       }
     }
     if (i == 0) {
       // Grab all of our frame request callbacks up front.
       nsTArray<DocumentFrameCallbacks>
         frameRequestCallbacks(mFrameRequestCallbackDocs.Length());
       for (uint32_t i = 0; i < mFrameRequestCallbackDocs.Length(); ++i) {
         frameRequestCallbacks.AppendElement(mFrameRequestCallbackDocs[i]);
         mFrameRequestCallbackDocs[i]->
           TakeFrameRequestCallbacks(frameRequestCallbacks.LastElement().mCallbacks);
       }
       // OK, now reset mFrameRequestCallbackDocs so they can be
       // readded as needed.
       mFrameRequestCallbackDocs.Clear();
       profiler_tracing("Paint", "Scripts", TRACING_INTERVAL_START);
       int64_t eventTime = aNowEpoch / PR_USEC_PER_MSEC;
       for (uint32_t i = 0; i < frameRequestCallbacks.Length(); ++i) {
         const DocumentFrameCallbacks& docCallbacks = frameRequestCallbacks[i];
         // XXXbz Bug 863140: GetInnerWindow can return the outer
         // window in some cases.
         nsPIDOMWindow* innerWindow = docCallbacks.mDocument->GetInnerWindow();
         DOMHighResTimeStamp timeStamp = 0;
         if (innerWindow && innerWindow->IsInnerWindow()) {
           nsPerformance* perf = innerWindow->GetPerformance();
           if (perf) {
             timeStamp = perf->GetDOMTiming()->TimeStampToDOMHighRes(aNowTime);
           }
           // else window is partially torn down already
         }
         for (uint32_t j = 0; j < docCallbacks.mCallbacks.Length(); ++j) {
           const nsIDocument::FrameRequestCallbackHolder& holder =
             docCallbacks.mCallbacks[j];
           nsAutoMicroTask mt;
           if (holder.HasWebIDLCallback()) {
             ErrorResult ignored;
             holder.GetWebIDLCallback()->Call(timeStamp, ignored);
           } else {
             holder.GetXPCOMCallback()->Sample(eventTime);
           }
         }
       }
       profiler_tracing("Paint", "Scripts", TRACING_INTERVAL_END);
       // This is the Flush_Style case.
       if (mPresContext && mPresContext->GetPresShell()) {
         nsAutoTArray<nsIPresShell*, 16> observers;
         observers.AppendElements(mStyleFlushObservers);
         for (uint32_t j = observers.Length();
              j && mPresContext && mPresContext->GetPresShell(); --j) {
           // Make sure to not process observers which might have been removed
           // during previous iterations.
           nsIPresShell* shell = observers[j - 1];
           if (!mStyleFlushObservers.Contains(shell))
             continue;
           NS_ADDREF(shell);
           mStyleFlushObservers.RemoveElement(shell);
           shell->GetPresContext()->RestyleManager()->mObservingRefreshDriver = false;
           shell->FlushPendingNotifications(ChangesToFlush(Flush_Style, false));
           NS_RELEASE(shell);
         }
       }
     } else if  (i == 1) {
       // This is the Flush_Layout case.
       if (mPresContext && mPresContext->GetPresShell()) {
         nsAutoTArray<nsIPresShell*, 16> observers;
         observers.AppendElements(mLayoutFlushObservers);
         for (uint32_t j = observers.Length();
              j && mPresContext && mPresContext->GetPresShell(); --j) {
           // Make sure to not process observers which might have been removed
           // during previous iterations.
           nsIPresShell* shell = observers[j - 1];
           if (!mLayoutFlushObservers.Contains(shell))
             continue;
           NS_ADDREF(shell);
           mLayoutFlushObservers.RemoveElement(shell);
           shell->mReflowScheduled = false;
           shell->mSuppressInterruptibleReflows = false;
           shell->FlushPendingNotifications(ChangesToFlush(Flush_InterruptibleLayout,
                                                           false));
           NS_RELEASE(shell);
         }
       }
     }
   }
   /*
    * Perform notification to imgIRequests subscribed to listen
    * for refresh events.
    */
   ImageRequestParameters parms = {aNowTime, previousRefresh, &mRequests};
   mStartTable.EnumerateRead(nsRefreshDriver::StartTableRefresh, &parms);
   if (mRequests.Count()) {
     // RequestRefresh may run scripts, so it's not safe to directly call it
     // while using a hashtable enumerator to enumerate mRequests in case
     // script modifies the hashtable. Instead, we build a (local) array of
     // images to refresh, and then we refresh each image in that array.
     nsCOMArray<imgIContainer> imagesToRefresh(mRequests.Count());
     mRequests.EnumerateEntries(nsRefreshDriver::ImageRequestEnumerator,
                                &imagesToRefresh);
     for (uint32_t i = 0; i < imagesToRefresh.Length(); i++) {
       imagesToRefresh[i]->RequestRefresh(aNowTime);
     }
   }
   for (uint32_t i = 0; i < mPresShellsToInvalidateIfHidden.Length(); i++) {
     mPresShellsToInvalidateIfHidden[i]->InvalidatePresShellIfHidden();
   }
   mPresShellsToInvalidateIfHidden.Clear();
   if (mViewManagerFlushIsPending) {
 #ifdef MOZ_DUMP_PAINTING
     if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
       printf_stderr("Starting ProcessPendingUpdates\n");
     }
 #endif
     mViewManagerFlushIsPending = false;
     nsRefPtr<nsViewManager> vm = mPresContext->GetPresShell()->GetViewManager();
     vm->ProcessPendingUpdates();
 #ifdef MOZ_DUMP_PAINTING
     if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
       printf_stderr("Ending ProcessPendingUpdates\n");
     }
 #endif
   }
   for (uint32_t i = 0; i < mPostRefreshObservers.Length(); ++i) {
     mPostRefreshObservers[i]->DidRefresh();
   }
   profiler_tracing("Paint", "RD", TRACING_INTERVAL_END);
   NS_ASSERTION(mInRefresh, "Still in refresh");
 }
 /* static */ PLDHashOperator
 nsRefreshDriver::ImageRequestEnumerator(nsISupportsHashKey* aEntry,
                                         void* aUserArg)
 {
   nsCOMArray<imgIContainer>* imagesToRefresh =
     static_cast<nsCOMArray<imgIContainer>*> (aUserArg);
   imgIRequest* req = static_cast<imgIRequest*>(aEntry->GetKey());
   NS_ABORT_IF_FALSE(req, "Unable to retrieve the image request");
   nsCOMPtr<imgIContainer> image;
   if (NS_SUCCEEDED(req->GetImage(getter_AddRefs(image)))) {
     imagesToRefresh->AppendElement(image);
   }
   return PL_DHASH_NEXT;
 }
 /* static */ PLDHashOperator
 nsRefreshDriver::BeginRefreshingImages(nsISupportsHashKey* aEntry,
                                        void* aUserArg)
 {
   ImageRequestParameters* parms =
     static_cast<ImageRequestParameters*> (aUserArg);
   imgIRequest* req = static_cast<imgIRequest*>(aEntry->GetKey());
   NS_ABORT_IF_FALSE(req, "Unable to retrieve the image request");
   parms->mRequests->PutEntry(req);
   nsCOMPtr<imgIContainer> image;
   if (NS_SUCCEEDED(req->GetImage(getter_AddRefs(image)))) {
     image->SetAnimationStartTime(parms->mDesired);
   }
   return PL_DHASH_REMOVE;
 }
 /* static */ PLDHashOperator
 nsRefreshDriver::StartTableRefresh(const uint32_t& aDelay,
                                    ImageStartData* aData,
                                    void* aUserArg)
 {
   ImageRequestParameters* parms =
     static_cast<ImageRequestParameters*> (aUserArg);
   if (!aData->mStartTime.empty()) {
     TimeStamp& start = aData->mStartTime.ref();
     TimeDuration prev = parms->mPrevious - start;
     TimeDuration curr = parms->mCurrent - start;
     uint32_t prevMultiple = static_cast<uint32_t>(prev.ToMilliseconds()) / aDelay;
     // We want to trigger images' refresh if we've just crossed over a multiple
     // of the first image's start time. If so, set the animation start time to
     // the nearest multiple of the delay and move all the images in this table
     // to the main requests table.
     if (prevMultiple != static_cast<uint32_t>(curr.ToMilliseconds()) / aDelay) {
       parms->mDesired = start + TimeDuration::FromMilliseconds(prevMultiple * aDelay);
       aData->mEntries.EnumerateEntries(nsRefreshDriver::BeginRefreshingImages, parms);
     }
   } else {
     // This is the very first time we've drawn images with this time delay.
     // Set the animation start time to "now" and move all the images in this
     // table to the main requests table.
     parms->mDesired = parms->mCurrent;
     aData->mEntries.EnumerateEntries(nsRefreshDriver::BeginRefreshingImages, parms);
     aData->mStartTime.construct(parms->mCurrent);
   }
   return PL_DHASH_NEXT;
 }
 void
 nsRefreshDriver::Freeze()
 {
   StopTimer();
   mFreezeCount++;
 }
 void
 nsRefreshDriver::Thaw()
 {
   NS_ASSERTION(mFreezeCount > 0, "Thaw() called on an unfrozen refresh driver");
   if (mFreezeCount > 0) {
     mFreezeCount--;
   }
   if (mFreezeCount == 0) {
     if (ObserverCount() || ImageRequestCount()) {
       // FIXME: This isn't quite right, since our EnsureTimerStarted call
       // updates our mMostRecentRefresh, but the DoRefresh call won't run
       // and notify our observers until we get back to the event loop.
       // Thus MostRecentRefresh() will lie between now and the DoRefresh.
       NS_DispatchToCurrentThread(NS_NewRunnableMethod(this, &nsRefreshDriver::DoRefresh));
       EnsureTimerStarted(false);
     }
   }
 }
 void
 nsRefreshDriver::SetThrottled(bool aThrottled)
 {
   if (aThrottled != mThrottled) {
     mThrottled = aThrottled;
     if (mActiveTimer) {
       // We want to switch our timer type here, so just stop and
       // restart the timer.
       EnsureTimerStarted(true);
     }
   }
 }
 void
 nsRefreshDriver::DoRefresh()
 {
   // Don't do a refresh unless we're in a state where we should be refreshing.
   if (!IsFrozen() && mPresContext && mActiveTimer) {
     DoTick();
   }
 }
 #ifdef DEBUG
 bool
 nsRefreshDriver::IsRefreshObserver(nsARefreshObserver* aObserver,
                                    mozFlushType aFlushType)
 {
   ObserverArray& array = ArrayFor(aFlushType);
   return array.Contains(aObserver);
 }
 #endif
 void
 nsRefreshDriver::ScheduleViewManagerFlush()
 {
   NS_ASSERTION(mPresContext->IsRoot(),
                "Should only schedule view manager flush on root prescontexts");
   mViewManagerFlushIsPending = true;
   EnsureTimerStarted(false);
 }
 void
 nsRefreshDriver::ScheduleFrameRequestCallbacks(nsIDocument* aDocument)
 {
   NS_ASSERTION(mFrameRequestCallbackDocs.IndexOf(aDocument) ==
                mFrameRequestCallbackDocs.NoIndex,
                "Don't schedule the same document multiple times");
   mFrameRequestCallbackDocs.AppendElement(aDocument);
   // make sure that the timer is running
   ConfigureHighPrecision();
   EnsureTimerStarted(false);
 }
 void
 nsRefreshDriver::RevokeFrameRequestCallbacks(nsIDocument* aDocument)
 {
   mFrameRequestCallbackDocs.RemoveElement(aDocument);
   ConfigureHighPrecision();
   // No need to worry about restarting our timer in slack mode if it's already
   // running; that will happen automatically when it fires.
 }
 #undef LOG

The Tor Browser / annotate

layout/base/nsRefreshDriver.cpp@b8a032363ba2 (annotated)

layout/base/nsRefreshDriver.cpp