gecko-dev/widget/gonk/GeckoTouchDispatcher.cpp
Mason Chang 96798fb9ef Bug 1193842 - Delete touch resampling preference and non resampling paths. r=kats
--HG--
extra : histedit_source : e8624dd77d2993cf52f1f5970cf0eed6b1555b44
2015-08-13 08:23:14 -07:00

346 lines
12 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sts=2 et sw=2 tw=80: */
/* Copyright 2014 Mozilla Foundation and Mozilla contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "FrameMetrics.h"
#include "GeckoProfiler.h"
#include "GeckoTouchDispatcher.h"
#include "InputData.h"
#include "ProfilerMarkers.h"
#include "base/basictypes.h"
#include "gfxPrefs.h"
#include "libui/Input.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Mutex.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/TouchEvents.h"
#include "mozilla/dom/Touch.h"
#include "mozilla/layers/APZThreadUtils.h"
#include "mozilla/layers/CompositorParent.h"
#include "nsAppShell.h"
#include "nsDebug.h"
#include "nsThreadUtils.h"
#include "nsWindow.h"
#include <sys/types.h>
#include <unistd.h>
#include <utils/Timers.h>
#define LOG(args...) \
__android_log_print(ANDROID_LOG_INFO, "Gonk" , ## args)
// uncomment to print log resample data
// #define LOG_RESAMPLE_DATA 1
namespace mozilla {
// Amount of time in MS before an input is considered expired.
static const uint64_t kInputExpirationThresholdMs = 1000;
static StaticRefPtr<GeckoTouchDispatcher> sTouchDispatcher;
/* static */ GeckoTouchDispatcher*
GeckoTouchDispatcher::GetInstance()
{
if (!sTouchDispatcher) {
sTouchDispatcher = new GeckoTouchDispatcher();
ClearOnShutdown(&sTouchDispatcher);
}
return sTouchDispatcher;
}
GeckoTouchDispatcher::GeckoTouchDispatcher()
: mTouchQueueLock("GeckoTouchDispatcher::mTouchQueueLock")
, mHavePendingTouchMoves(false)
, mInflightNonMoveEvents(0)
, mTouchEventsFiltered(false)
{
// Since GeckoTouchDispatcher is initialized when input is initialized
// and reads gfxPrefs, it is the first thing to touch gfxPrefs.
// The first thing to touch gfxPrefs MUST occur on the main thread and init
// the singleton
MOZ_ASSERT(sTouchDispatcher == nullptr);
MOZ_ASSERT(NS_IsMainThread());
gfxPrefs::GetSingleton();
mEnabledUniformityInfo = gfxPrefs::UniformityInfo();
mVsyncAdjust = TimeDuration::FromMilliseconds(gfxPrefs::TouchVsyncSampleAdjust());
mMaxPredict = TimeDuration::FromMilliseconds(gfxPrefs::TouchResampleMaxPredict());
mOldTouchThreshold = TimeDuration::FromMilliseconds(gfxPrefs::TouchResampleOldTouchThreshold());
mDelayedVsyncThreshold = TimeDuration::FromMilliseconds(gfxPrefs::TouchResampleVsyncDelayThreshold());
}
void
GeckoTouchDispatcher::SetCompositorVsyncScheduler(mozilla::layers::CompositorVsyncScheduler *aObserver)
{
MOZ_ASSERT(NS_IsMainThread());
// We assume on b2g that there is only 1 CompositorParent
MOZ_ASSERT(mCompositorVsyncScheduler == nullptr);
mCompositorVsyncScheduler = aObserver;
}
void
GeckoTouchDispatcher::NotifyVsync(TimeStamp aVsyncTimestamp)
{
layers::APZThreadUtils::AssertOnControllerThread();
DispatchTouchMoveEvents(aVsyncTimestamp);
}
// Touch data timestamps are in milliseconds, aEventTime is in nanoseconds
void
GeckoTouchDispatcher::NotifyTouch(MultiTouchInput& aTouch, TimeStamp aEventTime)
{
if (mCompositorVsyncScheduler) {
mCompositorVsyncScheduler->SetNeedsComposite(true);
}
if (aTouch.mType == MultiTouchInput::MULTITOUCH_MOVE) {
MutexAutoLock lock(mTouchQueueLock);
if (mInflightNonMoveEvents > 0) {
// If we have any pending non-move events, we shouldn't resample the
// move events because we might end up dispatching events out of order.
// Instead, fall back to a non-resampling in-order dispatch until we're
// done processing the non-move events.
layers::APZThreadUtils::RunOnControllerThread(NewRunnableMethod(
this, &GeckoTouchDispatcher::DispatchTouchEvent, aTouch));
return;
}
mTouchMoveEvents.push_back(aTouch);
mHavePendingTouchMoves = true;
} else {
{ // scope lock
MutexAutoLock lock(mTouchQueueLock);
mInflightNonMoveEvents++;
}
layers::APZThreadUtils::RunOnControllerThread(NewRunnableMethod(
this, &GeckoTouchDispatcher::DispatchTouchNonMoveEvent, aTouch));
}
}
void
GeckoTouchDispatcher::DispatchTouchNonMoveEvent(MultiTouchInput aInput)
{
layers::APZThreadUtils::AssertOnControllerThread();
// Flush pending touch move events, if there are any
// (DispatchTouchMoveEvents will check the mHavePendingTouchMoves flag and
// bail out if there's nothing to be done).
NotifyVsync(TimeStamp::Now());
DispatchTouchEvent(aInput);
{ // scope lock
MutexAutoLock lock(mTouchQueueLock);
mInflightNonMoveEvents--;
MOZ_ASSERT(mInflightNonMoveEvents >= 0);
}
}
void
GeckoTouchDispatcher::DispatchTouchMoveEvents(TimeStamp aVsyncTime)
{
MultiTouchInput touchMove;
{
MutexAutoLock lock(mTouchQueueLock);
if (!mHavePendingTouchMoves) {
return;
}
mHavePendingTouchMoves = false;
int touchCount = mTouchMoveEvents.size();
TimeDuration vsyncTouchDiff = aVsyncTime - mTouchMoveEvents.back().mTimeStamp;
// The delay threshold is a positive pref, but we're testing to see if the
// vsync time is delayed from the touch, so add a negative sign.
bool isDelayedVsyncEvent = vsyncTouchDiff < -mDelayedVsyncThreshold;
bool isOldTouch = vsyncTouchDiff > mOldTouchThreshold;
bool resample = (touchCount > 1) && !isDelayedVsyncEvent && !isOldTouch;
if (!resample) {
touchMove = mTouchMoveEvents.back();
mTouchMoveEvents.clear();
if (!isDelayedVsyncEvent && !isOldTouch) {
mTouchMoveEvents.push_back(touchMove);
}
} else {
ResampleTouchMoves(touchMove, aVsyncTime);
}
}
DispatchTouchEvent(touchMove);
}
static int
Interpolate(int start, int end, TimeDuration aFrameDiff, TimeDuration aTouchDiff)
{
return start + (((end - start) * aFrameDiff.ToMicroseconds()) / aTouchDiff.ToMicroseconds());
}
static const SingleTouchData&
GetTouchByID(const SingleTouchData& aCurrentTouch, MultiTouchInput& aOtherTouch)
{
int32_t index = aOtherTouch.IndexOfTouch(aCurrentTouch.mIdentifier);
if (index < 0) {
// We can have situations where a previous touch event had 2 fingers
// and we lift 1 finger off. In those cases, we won't find the touch event
// with given id, so just return the current touch, which will be resampled
// without modification and dispatched.
return aCurrentTouch;
}
return aOtherTouch.mTouches[index];
}
// aTouchDiff is the duration between the base and current touch times
// aFrameDiff is the duration between the base and the time we're resampling to
static void
ResampleTouch(MultiTouchInput& aOutTouch,
MultiTouchInput& aBase, MultiTouchInput& aCurrent,
TimeDuration aFrameDiff, TimeDuration aTouchDiff)
{
aOutTouch = aCurrent;
// Make sure we only resample the correct finger.
for (size_t i = 0; i < aOutTouch.mTouches.Length(); i++) {
const SingleTouchData& current = aCurrent.mTouches[i];
const SingleTouchData& base = GetTouchByID(current, aBase);
const ScreenIntPoint& baseTouchPoint = base.mScreenPoint;
const ScreenIntPoint& currentTouchPoint = current.mScreenPoint;
ScreenIntPoint newSamplePoint;
newSamplePoint.x = Interpolate(baseTouchPoint.x, currentTouchPoint.x, aFrameDiff, aTouchDiff);
newSamplePoint.y = Interpolate(baseTouchPoint.y, currentTouchPoint.y, aFrameDiff, aTouchDiff);
aOutTouch.mTouches[i].mScreenPoint = newSamplePoint;
#ifdef LOG_RESAMPLE_DATA
const char* type = "extrapolate";
if (aFrameDiff < aTouchDiff) {
type = "interpolate";
}
float alpha = aFrameDiff / aTouchDiff;
LOG("%s base (%d, %d), current (%d, %d) to (%d, %d) alpha %f, touch diff %d, frame diff %d\n",
type,
baseTouchPoint.x, baseTouchPoint.y,
currentTouchPoint.x, currentTouchPoint.y,
newSamplePoint.x, newSamplePoint.y,
alpha, (int)aTouchDiff.ToMilliseconds(), (int)aFrameDiff.ToMilliseconds());
#endif
}
}
/*
* +> Base touch (The touch before current touch)
* |
* | +> Current touch (Latest touch)
* | |
* | | +> Maximum resample time
* | | |
* +-----+------+--------------------> Time
* ^ ^
* | |
* +------+--> Potential vsync events which the touches are resampled to
* | |
* | +> Extrapolation
* |
* +> Interpolation
*/
void
GeckoTouchDispatcher::ResampleTouchMoves(MultiTouchInput& aOutTouch, TimeStamp aVsyncTime)
{
MOZ_RELEASE_ASSERT(mTouchMoveEvents.size() >= 2);
mTouchQueueLock.AssertCurrentThreadOwns();
MultiTouchInput currentTouch = mTouchMoveEvents.back();
mTouchMoveEvents.pop_back();
MultiTouchInput baseTouch = mTouchMoveEvents.back();
mTouchMoveEvents.clear();
mTouchMoveEvents.push_back(currentTouch);
TimeStamp sampleTime = aVsyncTime - mVsyncAdjust;
TimeDuration touchDiff = currentTouch.mTimeStamp - baseTouch.mTimeStamp;
if (currentTouch.mTimeStamp < sampleTime) {
TimeDuration maxResampleTime = std::min(touchDiff / int64_t(2), mMaxPredict);
TimeStamp maxTimestamp = currentTouch.mTimeStamp + maxResampleTime;
if (sampleTime > maxTimestamp) {
sampleTime = maxTimestamp;
#ifdef LOG_RESAMPLE_DATA
LOG("Overshot extrapolation time, adjusting sample time\n");
#endif
}
}
ResampleTouch(aOutTouch, baseTouch, currentTouch, sampleTime - baseTouch.mTimeStamp, touchDiff);
// Both mTimeStamp and mTime are being updated to sampleTime here.
// mTime needs to be updated using a delta since TimeStamp doesn't
// provide a way to obtain a raw value.
aOutTouch.mTime += (sampleTime - aOutTouch.mTimeStamp).ToMilliseconds();
aOutTouch.mTimeStamp = sampleTime;
}
static bool
IsExpired(const MultiTouchInput& aTouch)
{
// No pending events, the filter state can be updated.
uint64_t timeNowMs = systemTime(SYSTEM_TIME_MONOTONIC) / 1000000;
return (timeNowMs - aTouch.mTime) > kInputExpirationThresholdMs;
}
void
GeckoTouchDispatcher::DispatchTouchEvent(MultiTouchInput aMultiTouch)
{
if ((aMultiTouch.mType == MultiTouchInput::MULTITOUCH_END ||
aMultiTouch.mType == MultiTouchInput::MULTITOUCH_CANCEL) &&
aMultiTouch.mTouches.Length() == 1) {
MutexAutoLock lock(mTouchQueueLock);
mTouchMoveEvents.clear();
} else if (aMultiTouch.mType == MultiTouchInput::MULTITOUCH_START &&
aMultiTouch.mTouches.Length() == 1) {
mTouchEventsFiltered = IsExpired(aMultiTouch);
}
if (mTouchEventsFiltered) {
return;
}
nsWindow::DispatchTouchInput(aMultiTouch);
if (mEnabledUniformityInfo && profiler_is_active()) {
const char* touchAction = "Invalid";
switch (aMultiTouch.mType) {
case MultiTouchInput::MULTITOUCH_START:
touchAction = "Touch_Event_Down";
break;
case MultiTouchInput::MULTITOUCH_MOVE:
touchAction = "Touch_Event_Move";
break;
case MultiTouchInput::MULTITOUCH_END:
case MultiTouchInput::MULTITOUCH_CANCEL:
touchAction = "Touch_Event_Up";
break;
}
const ScreenIntPoint& touchPoint = aMultiTouch.mTouches[0].mScreenPoint;
TouchDataPayload* payload = new TouchDataPayload(touchPoint);
PROFILER_MARKER_PAYLOAD(touchAction, payload);
}
}
} // namespace mozilla