|  | /* | 
|  | * Copyright (C) 2013 The Android Open Source Project | 
|  | * | 
|  | * 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. | 
|  | */ | 
|  |  | 
|  | #define ATRACE_TAG ATRACE_TAG_GRAPHICS | 
|  | //#define LOG_NDEBUG 0 | 
|  |  | 
|  | // This is needed for stdint.h to define INT64_MAX in C++ | 
|  | #define __STDC_LIMIT_MACROS | 
|  |  | 
|  | #include <math.h> | 
|  |  | 
|  | #include <algorithm> | 
|  |  | 
|  | #include <android-base/stringprintf.h> | 
|  | #include <cutils/properties.h> | 
|  | #include <log/log.h> | 
|  | #include <utils/Thread.h> | 
|  | #include <utils/Trace.h> | 
|  |  | 
|  | #include <ui/FenceTime.h> | 
|  |  | 
|  | #include "DispSync.h" | 
|  | #include "EventLog/EventLog.h" | 
|  | #include "SurfaceFlinger.h" | 
|  |  | 
|  | using android::base::StringAppendF; | 
|  | using std::max; | 
|  | using std::min; | 
|  |  | 
|  | namespace android { | 
|  |  | 
|  | DispSync::~DispSync() = default; | 
|  | DispSync::Callback::~Callback() = default; | 
|  |  | 
|  | namespace impl { | 
|  |  | 
|  | // Setting this to true adds a zero-phase tracer for correlating with hardware | 
|  | // vsync events | 
|  | static const bool kEnableZeroPhaseTracer = false; | 
|  |  | 
|  | // This is the threshold used to determine when hardware vsync events are | 
|  | // needed to re-synchronize the software vsync model with the hardware.  The | 
|  | // error metric used is the mean of the squared difference between each | 
|  | // present time and the nearest software-predicted vsync. | 
|  | static const nsecs_t kErrorThreshold = 160000000000; // 400 usec squared | 
|  |  | 
|  | #undef LOG_TAG | 
|  | #define LOG_TAG "DispSyncThread" | 
|  | class DispSyncThread : public Thread { | 
|  | public: | 
|  | DispSyncThread(const char* name, bool showTraceDetailedInfo) | 
|  | : mName(name), | 
|  | mStop(false), | 
|  | mModelLocked(false), | 
|  | mPeriod(0), | 
|  | mPhase(0), | 
|  | mReferenceTime(0), | 
|  | mWakeupLatency(0), | 
|  | mFrameNumber(0), | 
|  | mTraceDetailedInfo(showTraceDetailedInfo) {} | 
|  |  | 
|  | virtual ~DispSyncThread() {} | 
|  |  | 
|  | void updateModel(nsecs_t period, nsecs_t phase, nsecs_t referenceTime) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | mPhase = phase; | 
|  | if (mReferenceTime != referenceTime) { | 
|  | for (auto& eventListener : mEventListeners) { | 
|  | eventListener.mHasFired = false; | 
|  | } | 
|  | } | 
|  | mReferenceTime = referenceTime; | 
|  | if (mPeriod != 0 && mPeriod != period && mReferenceTime != 0) { | 
|  | // Inflate the reference time to be the most recent predicted | 
|  | // vsync before the current time. | 
|  | const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC); | 
|  | const nsecs_t baseTime = now - mReferenceTime; | 
|  | const nsecs_t numOldPeriods = baseTime / mPeriod; | 
|  | mReferenceTime = mReferenceTime + (numOldPeriods)*mPeriod; | 
|  | } | 
|  | mPeriod = period; | 
|  | if (mTraceDetailedInfo) { | 
|  | ATRACE_INT64("DispSync:Period", mPeriod); | 
|  | ATRACE_INT64("DispSync:Phase", mPhase + mPeriod / 2); | 
|  | ATRACE_INT64("DispSync:Reference Time", mReferenceTime); | 
|  | } | 
|  | ALOGV("[%s] updateModel: mPeriod = %" PRId64 ", mPhase = %" PRId64 | 
|  | " mReferenceTime = %" PRId64, | 
|  | mName, ns2us(mPeriod), ns2us(mPhase), ns2us(mReferenceTime)); | 
|  | mCond.signal(); | 
|  | } | 
|  |  | 
|  | void stop() { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | Mutex::Autolock lock(mMutex); | 
|  | mStop = true; | 
|  | mCond.signal(); | 
|  | } | 
|  |  | 
|  | void lockModel() { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | mModelLocked = true; | 
|  | } | 
|  |  | 
|  | void unlockModel() { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | mModelLocked = false; | 
|  | } | 
|  |  | 
|  | virtual bool threadLoop() { | 
|  | status_t err; | 
|  | nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC); | 
|  |  | 
|  | while (true) { | 
|  | std::vector<CallbackInvocation> callbackInvocations; | 
|  |  | 
|  | nsecs_t targetTime = 0; | 
|  |  | 
|  | { // Scope for lock | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | if (mTraceDetailedInfo) { | 
|  | ATRACE_INT64("DispSync:Frame", mFrameNumber); | 
|  | } | 
|  | ALOGV("[%s] Frame %" PRId64, mName, mFrameNumber); | 
|  | ++mFrameNumber; | 
|  |  | 
|  | if (mStop) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (mPeriod == 0) { | 
|  | err = mCond.wait(mMutex); | 
|  | if (err != NO_ERROR) { | 
|  | ALOGE("error waiting for new events: %s (%d)", strerror(-err), err); | 
|  | return false; | 
|  | } | 
|  | continue; | 
|  | } | 
|  |  | 
|  | targetTime = computeNextEventTimeLocked(now); | 
|  |  | 
|  | bool isWakeup = false; | 
|  |  | 
|  | if (now < targetTime) { | 
|  | if (mTraceDetailedInfo) ATRACE_NAME("DispSync waiting"); | 
|  |  | 
|  | if (targetTime == INT64_MAX) { | 
|  | ALOGV("[%s] Waiting forever", mName); | 
|  | err = mCond.wait(mMutex); | 
|  | } else { | 
|  | ALOGV("[%s] Waiting until %" PRId64, mName, ns2us(targetTime)); | 
|  | err = mCond.waitRelative(mMutex, targetTime - now); | 
|  | } | 
|  |  | 
|  | if (err == TIMED_OUT) { | 
|  | isWakeup = true; | 
|  | } else if (err != NO_ERROR) { | 
|  | ALOGE("error waiting for next event: %s (%d)", strerror(-err), err); | 
|  | return false; | 
|  | } | 
|  | } | 
|  |  | 
|  | now = systemTime(SYSTEM_TIME_MONOTONIC); | 
|  |  | 
|  | // Don't correct by more than 1.5 ms | 
|  | static const nsecs_t kMaxWakeupLatency = us2ns(1500); | 
|  |  | 
|  | if (isWakeup) { | 
|  | mWakeupLatency = ((mWakeupLatency * 63) + (now - targetTime)) / 64; | 
|  | mWakeupLatency = min(mWakeupLatency, kMaxWakeupLatency); | 
|  | if (mTraceDetailedInfo) { | 
|  | ATRACE_INT64("DispSync:WakeupLat", now - targetTime); | 
|  | ATRACE_INT64("DispSync:AvgWakeupLat", mWakeupLatency); | 
|  | } | 
|  | } | 
|  |  | 
|  | callbackInvocations = gatherCallbackInvocationsLocked(now); | 
|  | } | 
|  |  | 
|  | if (callbackInvocations.size() > 0) { | 
|  | fireCallbackInvocations(callbackInvocations); | 
|  | } | 
|  | } | 
|  |  | 
|  | return false; | 
|  | } | 
|  |  | 
|  | status_t addEventListener(const char* name, nsecs_t phase, DispSync::Callback* callback, | 
|  | nsecs_t lastCallbackTime) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | for (size_t i = 0; i < mEventListeners.size(); i++) { | 
|  | if (mEventListeners[i].mCallback == callback) { | 
|  | return BAD_VALUE; | 
|  | } | 
|  | } | 
|  |  | 
|  | EventListener listener; | 
|  | listener.mName = name; | 
|  | listener.mPhase = phase; | 
|  | listener.mCallback = callback; | 
|  |  | 
|  | // We want to allow the firstmost future event to fire without | 
|  | // allowing any past events to fire. To do this extrapolate from | 
|  | // mReferenceTime the most recent hardware vsync, and pin the | 
|  | // last event time there. | 
|  | const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC); | 
|  | if (mPeriod != 0) { | 
|  | const nsecs_t baseTime = now - mReferenceTime; | 
|  | const nsecs_t numPeriodsSinceReference = baseTime / mPeriod; | 
|  | const nsecs_t predictedReference = mReferenceTime + numPeriodsSinceReference * mPeriod; | 
|  | const nsecs_t phaseCorrection = mPhase + listener.mPhase; | 
|  | const nsecs_t predictedLastEventTime = predictedReference + phaseCorrection; | 
|  | if (predictedLastEventTime >= now) { | 
|  | // Make sure that the last event time does not exceed the current time. | 
|  | // If it would, then back the last event time by a period. | 
|  | listener.mLastEventTime = predictedLastEventTime - mPeriod; | 
|  | } else { | 
|  | listener.mLastEventTime = predictedLastEventTime; | 
|  | } | 
|  | } else { | 
|  | listener.mLastEventTime = now + mPhase - mWakeupLatency; | 
|  | } | 
|  |  | 
|  | if (lastCallbackTime <= 0) { | 
|  | // If there is no prior callback time, try to infer one based on the | 
|  | // logical last event time. | 
|  | listener.mLastCallbackTime = listener.mLastEventTime + mWakeupLatency; | 
|  | } else { | 
|  | listener.mLastCallbackTime = lastCallbackTime; | 
|  | } | 
|  |  | 
|  | mEventListeners.push_back(listener); | 
|  |  | 
|  | mCond.signal(); | 
|  |  | 
|  | return NO_ERROR; | 
|  | } | 
|  |  | 
|  | status_t removeEventListener(DispSync::Callback* callback, nsecs_t* outLastCallback) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | for (std::vector<EventListener>::iterator it = mEventListeners.begin(); | 
|  | it != mEventListeners.end(); ++it) { | 
|  | if (it->mCallback == callback) { | 
|  | *outLastCallback = it->mLastCallbackTime; | 
|  | mEventListeners.erase(it); | 
|  | mCond.signal(); | 
|  | return NO_ERROR; | 
|  | } | 
|  | } | 
|  |  | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | status_t changePhaseOffset(DispSync::Callback* callback, nsecs_t phase) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | for (auto& eventListener : mEventListeners) { | 
|  | if (eventListener.mCallback == callback) { | 
|  | const nsecs_t oldPhase = eventListener.mPhase; | 
|  | eventListener.mPhase = phase; | 
|  |  | 
|  | // Pretend that the last time this event was handled at the same frame but with the | 
|  | // new offset to allow for a seamless offset change without double-firing or | 
|  | // skipping. | 
|  | nsecs_t diff = oldPhase - phase; | 
|  | if (diff > mPeriod / 2) { | 
|  | diff -= mPeriod; | 
|  | } else if (diff < -mPeriod / 2) { | 
|  | diff += mPeriod; | 
|  | } | 
|  | eventListener.mLastEventTime -= diff; | 
|  | mCond.signal(); | 
|  | return NO_ERROR; | 
|  | } | 
|  | } | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | private: | 
|  | struct EventListener { | 
|  | const char* mName; | 
|  | nsecs_t mPhase; | 
|  | nsecs_t mLastEventTime; | 
|  | nsecs_t mLastCallbackTime; | 
|  | DispSync::Callback* mCallback; | 
|  | bool mHasFired = false; | 
|  | }; | 
|  |  | 
|  | struct CallbackInvocation { | 
|  | DispSync::Callback* mCallback; | 
|  | nsecs_t mEventTime; | 
|  | }; | 
|  |  | 
|  | nsecs_t computeNextEventTimeLocked(nsecs_t now) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | ALOGV("[%s] computeNextEventTimeLocked", mName); | 
|  | nsecs_t nextEventTime = INT64_MAX; | 
|  | for (size_t i = 0; i < mEventListeners.size(); i++) { | 
|  | nsecs_t t = computeListenerNextEventTimeLocked(mEventListeners[i], now); | 
|  |  | 
|  | if (t < nextEventTime) { | 
|  | nextEventTime = t; | 
|  | } | 
|  | } | 
|  |  | 
|  | ALOGV("[%s] nextEventTime = %" PRId64, mName, ns2us(nextEventTime)); | 
|  | return nextEventTime; | 
|  | } | 
|  |  | 
|  | // Sanity check that the duration is close enough in length to a period without | 
|  | // falling into double-rate vsyncs. | 
|  | bool isCloseToPeriod(nsecs_t duration) { | 
|  | // Ratio of 3/5 is arbitrary, but it must be greater than 1/2. | 
|  | return duration < (3 * mPeriod) / 5; | 
|  | } | 
|  |  | 
|  | std::vector<CallbackInvocation> gatherCallbackInvocationsLocked(nsecs_t now) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | ALOGV("[%s] gatherCallbackInvocationsLocked @ %" PRId64, mName, ns2us(now)); | 
|  |  | 
|  | std::vector<CallbackInvocation> callbackInvocations; | 
|  | nsecs_t onePeriodAgo = now - mPeriod; | 
|  |  | 
|  | for (auto& eventListener : mEventListeners) { | 
|  | nsecs_t t = computeListenerNextEventTimeLocked(eventListener, onePeriodAgo); | 
|  |  | 
|  | if (t < now) { | 
|  | if (isCloseToPeriod(now - eventListener.mLastCallbackTime)) { | 
|  | eventListener.mLastEventTime = t; | 
|  | ALOGV("[%s] [%s] Skipping event due to model error", mName, | 
|  | eventListener.mName); | 
|  | continue; | 
|  | } | 
|  | if (eventListener.mHasFired && !mModelLocked) { | 
|  | eventListener.mLastEventTime = t; | 
|  | ALOGV("[%s] [%s] Skipping event due to already firing", mName, | 
|  | eventListener.mName); | 
|  | continue; | 
|  | } | 
|  | CallbackInvocation ci; | 
|  | ci.mCallback = eventListener.mCallback; | 
|  | ci.mEventTime = t; | 
|  | ALOGV("[%s] [%s] Preparing to fire, latency: %" PRId64, mName, eventListener.mName, | 
|  | t - eventListener.mLastEventTime); | 
|  | callbackInvocations.push_back(ci); | 
|  | eventListener.mLastEventTime = t; | 
|  | eventListener.mLastCallbackTime = now; | 
|  | eventListener.mHasFired = true; | 
|  | } | 
|  | } | 
|  |  | 
|  | return callbackInvocations; | 
|  | } | 
|  |  | 
|  | nsecs_t computeListenerNextEventTimeLocked(const EventListener& listener, nsecs_t baseTime) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | ALOGV("[%s] [%s] computeListenerNextEventTimeLocked(%" PRId64 ")", mName, listener.mName, | 
|  | ns2us(baseTime)); | 
|  |  | 
|  | nsecs_t lastEventTime = listener.mLastEventTime + mWakeupLatency; | 
|  | ALOGV("[%s] lastEventTime: %" PRId64, mName, ns2us(lastEventTime)); | 
|  | if (baseTime < lastEventTime) { | 
|  | baseTime = lastEventTime; | 
|  | ALOGV("[%s] Clamping baseTime to lastEventTime -> %" PRId64, mName, ns2us(baseTime)); | 
|  | } | 
|  |  | 
|  | baseTime -= mReferenceTime; | 
|  | ALOGV("[%s] Relative baseTime = %" PRId64, mName, ns2us(baseTime)); | 
|  | nsecs_t phase = mPhase + listener.mPhase; | 
|  | ALOGV("[%s] Phase = %" PRId64, mName, ns2us(phase)); | 
|  | baseTime -= phase; | 
|  | ALOGV("[%s] baseTime - phase = %" PRId64, mName, ns2us(baseTime)); | 
|  |  | 
|  | // If our previous time is before the reference (because the reference | 
|  | // has since been updated), the division by mPeriod will truncate | 
|  | // towards zero instead of computing the floor. Since in all cases | 
|  | // before the reference we want the next time to be effectively now, we | 
|  | // set baseTime to -mPeriod so that numPeriods will be -1. | 
|  | // When we add 1 and the phase, we will be at the correct event time for | 
|  | // this period. | 
|  | if (baseTime < 0) { | 
|  | ALOGV("[%s] Correcting negative baseTime", mName); | 
|  | baseTime = -mPeriod; | 
|  | } | 
|  |  | 
|  | nsecs_t numPeriods = baseTime / mPeriod; | 
|  | ALOGV("[%s] numPeriods = %" PRId64, mName, numPeriods); | 
|  | nsecs_t t = (numPeriods + 1) * mPeriod + phase; | 
|  | ALOGV("[%s] t = %" PRId64, mName, ns2us(t)); | 
|  | t += mReferenceTime; | 
|  | ALOGV("[%s] Absolute t = %" PRId64, mName, ns2us(t)); | 
|  |  | 
|  | // Check that it's been slightly more than half a period since the last | 
|  | // event so that we don't accidentally fall into double-rate vsyncs | 
|  | if (isCloseToPeriod(t - listener.mLastEventTime)) { | 
|  | t += mPeriod; | 
|  | ALOGV("[%s] Modifying t -> %" PRId64, mName, ns2us(t)); | 
|  | } | 
|  |  | 
|  | t -= mWakeupLatency; | 
|  | ALOGV("[%s] Corrected for wakeup latency -> %" PRId64, mName, ns2us(t)); | 
|  |  | 
|  | return t; | 
|  | } | 
|  |  | 
|  | void fireCallbackInvocations(const std::vector<CallbackInvocation>& callbacks) { | 
|  | if (mTraceDetailedInfo) ATRACE_CALL(); | 
|  | for (size_t i = 0; i < callbacks.size(); i++) { | 
|  | callbacks[i].mCallback->onDispSyncEvent(callbacks[i].mEventTime); | 
|  | } | 
|  | } | 
|  |  | 
|  | const char* const mName; | 
|  |  | 
|  | bool mStop; | 
|  | bool mModelLocked; | 
|  |  | 
|  | nsecs_t mPeriod; | 
|  | nsecs_t mPhase; | 
|  | nsecs_t mReferenceTime; | 
|  | nsecs_t mWakeupLatency; | 
|  |  | 
|  | int64_t mFrameNumber; | 
|  |  | 
|  | std::vector<EventListener> mEventListeners; | 
|  |  | 
|  | Mutex mMutex; | 
|  | Condition mCond; | 
|  |  | 
|  | // Flag to turn on logging in systrace. | 
|  | const bool mTraceDetailedInfo; | 
|  | }; | 
|  |  | 
|  | #undef LOG_TAG | 
|  | #define LOG_TAG "DispSync" | 
|  |  | 
|  | class ZeroPhaseTracer : public DispSync::Callback { | 
|  | public: | 
|  | ZeroPhaseTracer() : mParity(false) {} | 
|  |  | 
|  | virtual void onDispSyncEvent(nsecs_t /*when*/) { | 
|  | mParity = !mParity; | 
|  | ATRACE_INT("ZERO_PHASE_VSYNC", mParity ? 1 : 0); | 
|  | } | 
|  |  | 
|  | private: | 
|  | bool mParity; | 
|  | }; | 
|  |  | 
|  | DispSync::DispSync(const char* name) : mName(name), mRefreshSkipCount(0) { | 
|  | // This flag offers the ability to turn on systrace logging from the shell. | 
|  | char value[PROPERTY_VALUE_MAX]; | 
|  | property_get("debug.sf.dispsync_trace_detailed_info", value, "0"); | 
|  | mTraceDetailedInfo = atoi(value); | 
|  | mThread = new DispSyncThread(name, mTraceDetailedInfo); | 
|  | } | 
|  |  | 
|  | DispSync::~DispSync() { | 
|  | mThread->stop(); | 
|  | mThread->requestExitAndWait(); | 
|  | } | 
|  |  | 
|  | void DispSync::init(bool hasSyncFramework, int64_t dispSyncPresentTimeOffset) { | 
|  | mIgnorePresentFences = !hasSyncFramework; | 
|  | mPresentTimeOffset = dispSyncPresentTimeOffset; | 
|  | mThread->run("DispSync", PRIORITY_URGENT_DISPLAY + PRIORITY_MORE_FAVORABLE); | 
|  |  | 
|  | // set DispSync to SCHED_FIFO to minimize jitter | 
|  | struct sched_param param = {0}; | 
|  | param.sched_priority = 2; | 
|  | if (sched_setscheduler(mThread->getTid(), SCHED_FIFO, ¶m) != 0) { | 
|  | ALOGE("Couldn't set SCHED_FIFO for DispSyncThread"); | 
|  | } | 
|  |  | 
|  | reset(); | 
|  | beginResync(); | 
|  |  | 
|  | if (mTraceDetailedInfo && kEnableZeroPhaseTracer) { | 
|  | mZeroPhaseTracer = std::make_unique<ZeroPhaseTracer>(); | 
|  | addEventListener("ZeroPhaseTracer", 0, mZeroPhaseTracer.get(), 0); | 
|  | } | 
|  | } | 
|  |  | 
|  | void DispSync::reset() { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | resetLocked(); | 
|  | } | 
|  |  | 
|  | void DispSync::resetLocked() { | 
|  | mPhase = 0; | 
|  | const size_t lastSampleIdx = (mFirstResyncSample + mNumResyncSamples - 1) % MAX_RESYNC_SAMPLES; | 
|  | // Keep the most recent sample, when we resync to hardware we'll overwrite this | 
|  | // with a more accurate signal | 
|  | if (mResyncSamples[lastSampleIdx] != 0) { | 
|  | mReferenceTime = mResyncSamples[lastSampleIdx]; | 
|  | } | 
|  | mModelUpdated = false; | 
|  | for (size_t i = 0; i < MAX_RESYNC_SAMPLES; i++) { | 
|  | mResyncSamples[i] = 0; | 
|  | } | 
|  | mNumResyncSamples = 0; | 
|  | mFirstResyncSample = 0; | 
|  | mNumResyncSamplesSincePresent = 0; | 
|  | mThread->unlockModel(); | 
|  | resetErrorLocked(); | 
|  | } | 
|  |  | 
|  | bool DispSync::addPresentFence(const std::shared_ptr<FenceTime>& fenceTime) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | if (mIgnorePresentFences) { | 
|  | return true; | 
|  | } | 
|  |  | 
|  | mPresentFences[mPresentSampleOffset] = fenceTime; | 
|  | mPresentSampleOffset = (mPresentSampleOffset + 1) % NUM_PRESENT_SAMPLES; | 
|  | mNumResyncSamplesSincePresent = 0; | 
|  |  | 
|  | updateErrorLocked(); | 
|  |  | 
|  | return !mModelUpdated || mError > kErrorThreshold; | 
|  | } | 
|  |  | 
|  | void DispSync::beginResync() { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | ALOGV("[%s] beginResync", mName); | 
|  | mThread->unlockModel(); | 
|  | mModelUpdated = false; | 
|  | mNumResyncSamples = 0; | 
|  | } | 
|  |  | 
|  | bool DispSync::addResyncSample(nsecs_t timestamp, bool* periodChanged) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  |  | 
|  | ALOGV("[%s] addResyncSample(%" PRId64 ")", mName, ns2us(timestamp)); | 
|  |  | 
|  | *periodChanged = false; | 
|  | const size_t idx = (mFirstResyncSample + mNumResyncSamples) % MAX_RESYNC_SAMPLES; | 
|  | mResyncSamples[idx] = timestamp; | 
|  | if (mNumResyncSamples == 0) { | 
|  | mPhase = 0; | 
|  | ALOGV("[%s] First resync sample: mPeriod = %" PRId64 ", mPhase = 0, " | 
|  | "mReferenceTime = %" PRId64, | 
|  | mName, ns2us(mPeriod), ns2us(timestamp)); | 
|  | } else if (mPendingPeriod > 0) { | 
|  | // mNumResyncSamples > 0, so priorIdx won't overflow | 
|  | const size_t priorIdx = (mFirstResyncSample + mNumResyncSamples - 1) % MAX_RESYNC_SAMPLES; | 
|  | const nsecs_t lastTimestamp = mResyncSamples[priorIdx]; | 
|  |  | 
|  | const nsecs_t observedVsync = std::abs(timestamp - lastTimestamp); | 
|  | if (std::abs(observedVsync - mPendingPeriod) < std::abs(observedVsync - mPeriod)) { | 
|  | // Observed vsync is closer to the pending period, so reset the | 
|  | // model and flush the pending period. | 
|  | resetLocked(); | 
|  | mPeriod = mPendingPeriod; | 
|  | mPendingPeriod = 0; | 
|  | if (mTraceDetailedInfo) { | 
|  | ATRACE_INT("DispSync:PendingPeriod", mPendingPeriod); | 
|  | } | 
|  | *periodChanged = true; | 
|  | } | 
|  | } | 
|  | // Always update the reference time with the most recent timestamp. | 
|  | mReferenceTime = timestamp; | 
|  | mThread->updateModel(mPeriod, mPhase, mReferenceTime); | 
|  |  | 
|  | if (mNumResyncSamples < MAX_RESYNC_SAMPLES) { | 
|  | mNumResyncSamples++; | 
|  | } else { | 
|  | mFirstResyncSample = (mFirstResyncSample + 1) % MAX_RESYNC_SAMPLES; | 
|  | } | 
|  |  | 
|  | updateModelLocked(); | 
|  |  | 
|  | if (mNumResyncSamplesSincePresent++ > MAX_RESYNC_SAMPLES_WITHOUT_PRESENT) { | 
|  | resetErrorLocked(); | 
|  | } | 
|  |  | 
|  | if (mIgnorePresentFences) { | 
|  | // If we're ignoring the present fences we have no way to know whether | 
|  | // or not we're synchronized with the HW vsyncs, so we just request | 
|  | // that the HW vsync events be turned on. | 
|  | return true; | 
|  | } | 
|  |  | 
|  | // Check against kErrorThreshold / 2 to add some hysteresis before having to | 
|  | // resync again | 
|  | bool modelLocked = mModelUpdated && mError < (kErrorThreshold / 2) && mPendingPeriod == 0; | 
|  | ALOGV("[%s] addResyncSample returning %s", mName, modelLocked ? "locked" : "unlocked"); | 
|  | if (modelLocked) { | 
|  | mThread->lockModel(); | 
|  | } | 
|  | return !modelLocked; | 
|  | } | 
|  |  | 
|  | void DispSync::endResync() { | 
|  | mThread->lockModel(); | 
|  | } | 
|  |  | 
|  | status_t DispSync::addEventListener(const char* name, nsecs_t phase, Callback* callback, | 
|  | nsecs_t lastCallbackTime) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | return mThread->addEventListener(name, phase, callback, lastCallbackTime); | 
|  | } | 
|  |  | 
|  | void DispSync::setRefreshSkipCount(int count) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | ALOGD("setRefreshSkipCount(%d)", count); | 
|  | mRefreshSkipCount = count; | 
|  | updateModelLocked(); | 
|  | } | 
|  |  | 
|  | status_t DispSync::removeEventListener(Callback* callback, nsecs_t* outLastCallbackTime) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | return mThread->removeEventListener(callback, outLastCallbackTime); | 
|  | } | 
|  |  | 
|  | status_t DispSync::changePhaseOffset(Callback* callback, nsecs_t phase) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | return mThread->changePhaseOffset(callback, phase); | 
|  | } | 
|  |  | 
|  | void DispSync::setPeriod(nsecs_t period) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | if (mTraceDetailedInfo) { | 
|  | ATRACE_INT("DispSync:PendingPeriod", period); | 
|  | } | 
|  | mPendingPeriod = period; | 
|  | } | 
|  |  | 
|  | nsecs_t DispSync::getPeriod() { | 
|  | // lock mutex as mPeriod changes multiple times in updateModelLocked | 
|  | Mutex::Autolock lock(mMutex); | 
|  | return mPeriod; | 
|  | } | 
|  |  | 
|  | void DispSync::updateModelLocked() { | 
|  | ALOGV("[%s] updateModelLocked %zu", mName, mNumResyncSamples); | 
|  | if (mNumResyncSamples >= MIN_RESYNC_SAMPLES_FOR_UPDATE) { | 
|  | ALOGV("[%s] Computing...", mName); | 
|  | nsecs_t durationSum = 0; | 
|  | nsecs_t minDuration = INT64_MAX; | 
|  | nsecs_t maxDuration = 0; | 
|  | for (size_t i = 1; i < mNumResyncSamples; i++) { | 
|  | size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES; | 
|  | size_t prev = (idx + MAX_RESYNC_SAMPLES - 1) % MAX_RESYNC_SAMPLES; | 
|  | nsecs_t duration = mResyncSamples[idx] - mResyncSamples[prev]; | 
|  | durationSum += duration; | 
|  | minDuration = min(minDuration, duration); | 
|  | maxDuration = max(maxDuration, duration); | 
|  | } | 
|  |  | 
|  | // Exclude the min and max from the average | 
|  | durationSum -= minDuration + maxDuration; | 
|  | mPeriod = durationSum / (mNumResyncSamples - 3); | 
|  |  | 
|  | ALOGV("[%s] mPeriod = %" PRId64, mName, ns2us(mPeriod)); | 
|  |  | 
|  | double sampleAvgX = 0; | 
|  | double sampleAvgY = 0; | 
|  | double scale = 2.0 * M_PI / double(mPeriod); | 
|  | // Intentionally skip the first sample | 
|  | for (size_t i = 1; i < mNumResyncSamples; i++) { | 
|  | size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES; | 
|  | nsecs_t sample = mResyncSamples[idx] - mReferenceTime; | 
|  | double samplePhase = double(sample % mPeriod) * scale; | 
|  | sampleAvgX += cos(samplePhase); | 
|  | sampleAvgY += sin(samplePhase); | 
|  | } | 
|  |  | 
|  | sampleAvgX /= double(mNumResyncSamples - 1); | 
|  | sampleAvgY /= double(mNumResyncSamples - 1); | 
|  |  | 
|  | mPhase = nsecs_t(atan2(sampleAvgY, sampleAvgX) / scale); | 
|  |  | 
|  | ALOGV("[%s] mPhase = %" PRId64, mName, ns2us(mPhase)); | 
|  |  | 
|  | if (mPhase < -(mPeriod / 2)) { | 
|  | mPhase += mPeriod; | 
|  | ALOGV("[%s] Adjusting mPhase -> %" PRId64, mName, ns2us(mPhase)); | 
|  | } | 
|  |  | 
|  | // Artificially inflate the period if requested. | 
|  | mPeriod += mPeriod * mRefreshSkipCount; | 
|  |  | 
|  | mThread->updateModel(mPeriod, mPhase, mReferenceTime); | 
|  | mModelUpdated = true; | 
|  | } | 
|  | } | 
|  |  | 
|  | void DispSync::updateErrorLocked() { | 
|  | if (!mModelUpdated) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | // Need to compare present fences against the un-adjusted refresh period, | 
|  | // since they might arrive between two events. | 
|  | nsecs_t period = mPeriod / (1 + mRefreshSkipCount); | 
|  |  | 
|  | int numErrSamples = 0; | 
|  | nsecs_t sqErrSum = 0; | 
|  |  | 
|  | for (size_t i = 0; i < NUM_PRESENT_SAMPLES; i++) { | 
|  | // Only check for the cached value of signal time to avoid unecessary | 
|  | // syscalls. It is the responsibility of the DispSync owner to | 
|  | // call getSignalTime() periodically so the cache is updated when the | 
|  | // fence signals. | 
|  | nsecs_t time = mPresentFences[i]->getCachedSignalTime(); | 
|  | if (time == Fence::SIGNAL_TIME_PENDING || time == Fence::SIGNAL_TIME_INVALID) { | 
|  | continue; | 
|  | } | 
|  |  | 
|  | nsecs_t sample = time - mReferenceTime; | 
|  | if (sample <= mPhase) { | 
|  | continue; | 
|  | } | 
|  |  | 
|  | nsecs_t sampleErr = (sample - mPhase) % period; | 
|  | if (sampleErr > period / 2) { | 
|  | sampleErr -= period; | 
|  | } | 
|  | sqErrSum += sampleErr * sampleErr; | 
|  | numErrSamples++; | 
|  | } | 
|  |  | 
|  | if (numErrSamples > 0) { | 
|  | mError = sqErrSum / numErrSamples; | 
|  | mZeroErrSamplesCount = 0; | 
|  | } else { | 
|  | mError = 0; | 
|  | // Use mod ACCEPTABLE_ZERO_ERR_SAMPLES_COUNT to avoid log spam. | 
|  | mZeroErrSamplesCount++; | 
|  | ALOGE_IF((mZeroErrSamplesCount % ACCEPTABLE_ZERO_ERR_SAMPLES_COUNT) == 0, | 
|  | "No present times for model error."); | 
|  | } | 
|  |  | 
|  | if (mTraceDetailedInfo) { | 
|  | ATRACE_INT64("DispSync:Error", mError); | 
|  | } | 
|  | } | 
|  |  | 
|  | void DispSync::resetErrorLocked() { | 
|  | mPresentSampleOffset = 0; | 
|  | mError = 0; | 
|  | mZeroErrSamplesCount = 0; | 
|  | for (size_t i = 0; i < NUM_PRESENT_SAMPLES; i++) { | 
|  | mPresentFences[i] = FenceTime::NO_FENCE; | 
|  | } | 
|  | } | 
|  |  | 
|  | nsecs_t DispSync::computeNextRefresh(int periodOffset) const { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC); | 
|  | nsecs_t phase = mReferenceTime + mPhase; | 
|  | if (mPeriod == 0) { | 
|  | return 0; | 
|  | } | 
|  | return (((now - phase) / mPeriod) + periodOffset + 1) * mPeriod + phase; | 
|  | } | 
|  |  | 
|  | void DispSync::setIgnorePresentFences(bool ignore) { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | if (mIgnorePresentFences != ignore) { | 
|  | mIgnorePresentFences = ignore; | 
|  | resetLocked(); | 
|  | } | 
|  | } | 
|  |  | 
|  | void DispSync::dump(std::string& result) const { | 
|  | Mutex::Autolock lock(mMutex); | 
|  | StringAppendF(&result, "present fences are %s\n", mIgnorePresentFences ? "ignored" : "used"); | 
|  | StringAppendF(&result, "mPeriod: %" PRId64 " ns (%.3f fps; skipCount=%d)\n", mPeriod, | 
|  | 1000000000.0 / mPeriod, mRefreshSkipCount); | 
|  | StringAppendF(&result, "mPhase: %" PRId64 " ns\n", mPhase); | 
|  | StringAppendF(&result, "mError: %" PRId64 " ns (sqrt=%.1f)\n", mError, sqrt(mError)); | 
|  | StringAppendF(&result, "mNumResyncSamplesSincePresent: %d (limit %d)\n", | 
|  | mNumResyncSamplesSincePresent, MAX_RESYNC_SAMPLES_WITHOUT_PRESENT); | 
|  | StringAppendF(&result, "mNumResyncSamples: %zd (max %d)\n", mNumResyncSamples, | 
|  | MAX_RESYNC_SAMPLES); | 
|  |  | 
|  | result.append("mResyncSamples:\n"); | 
|  | nsecs_t previous = -1; | 
|  | for (size_t i = 0; i < mNumResyncSamples; i++) { | 
|  | size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES; | 
|  | nsecs_t sampleTime = mResyncSamples[idx]; | 
|  | if (i == 0) { | 
|  | StringAppendF(&result, "  %" PRId64 "\n", sampleTime); | 
|  | } else { | 
|  | StringAppendF(&result, "  %" PRId64 " (+%" PRId64 ")\n", sampleTime, | 
|  | sampleTime - previous); | 
|  | } | 
|  | previous = sampleTime; | 
|  | } | 
|  |  | 
|  | StringAppendF(&result, "mPresentFences [%d]:\n", NUM_PRESENT_SAMPLES); | 
|  | nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC); | 
|  | previous = Fence::SIGNAL_TIME_INVALID; | 
|  | for (size_t i = 0; i < NUM_PRESENT_SAMPLES; i++) { | 
|  | size_t idx = (i + mPresentSampleOffset) % NUM_PRESENT_SAMPLES; | 
|  | nsecs_t presentTime = mPresentFences[idx]->getSignalTime(); | 
|  | if (presentTime == Fence::SIGNAL_TIME_PENDING) { | 
|  | StringAppendF(&result, "  [unsignaled fence]\n"); | 
|  | } else if (presentTime == Fence::SIGNAL_TIME_INVALID) { | 
|  | StringAppendF(&result, "  [invalid fence]\n"); | 
|  | } else if (previous == Fence::SIGNAL_TIME_PENDING || | 
|  | previous == Fence::SIGNAL_TIME_INVALID) { | 
|  | StringAppendF(&result, "  %" PRId64 "  (%.3f ms ago)\n", presentTime, | 
|  | (now - presentTime) / 1000000.0); | 
|  | } else { | 
|  | StringAppendF(&result, "  %" PRId64 " (+%" PRId64 " / %.3f)  (%.3f ms ago)\n", | 
|  | presentTime, presentTime - previous, | 
|  | (presentTime - previous) / (double)mPeriod, | 
|  | (now - presentTime) / 1000000.0); | 
|  | } | 
|  | previous = presentTime; | 
|  | } | 
|  |  | 
|  | StringAppendF(&result, "current monotonic time: %" PRId64 "\n", now); | 
|  | } | 
|  |  | 
|  | nsecs_t DispSync::expectedPresentTime() { | 
|  | // The HWC doesn't currently have a way to report additional latency. | 
|  | // Assume that whatever we submit now will appear right after the flip. | 
|  | // For a smart panel this might be 1.  This is expressed in frames, | 
|  | // rather than time, because we expect to have a constant frame delay | 
|  | // regardless of the refresh rate. | 
|  | const uint32_t hwcLatency = 0; | 
|  |  | 
|  | // Ask DispSync when the next refresh will be (CLOCK_MONOTONIC). | 
|  | return computeNextRefresh(hwcLatency); | 
|  | } | 
|  |  | 
|  | } // namespace impl | 
|  |  | 
|  | } // namespace android |