Merge "Revert "Revert "DispSync: Always resync after inactivity""" into... (5fdd8207) · Commits · e / os / android_frameworks_native

services/surfaceflinger/DispSync.cpp

+148 −39

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		*/

		#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
		@@ -33,12 +34,21 @@
		#include "DispSync.h"
		#include "EventLog/EventLog.h"

		#include <algorithm>

		using std::max;
		using std::min;

		namespace android {

		// Setting this to true enables verbose tracing that can be used to debug
		// vsync event model or phase issues.
		static const bool kTraceDetailedInfo = false;

		// 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
		@@ -49,28 +59,36 @@ static const nsecs_t kErrorThreshold = 160000000000; // 400 usec squared
		// vsync event.
		static const int64_t kPresentTimeOffset = PRESENT_TIME_OFFSET_FROM_VSYNC_NS;

		#undef LOG_TAG
		#define LOG_TAG "DispSyncThread"
		class DispSyncThread: public Thread {
		public:

		DispSyncThread():
		DispSyncThread(const char* name):
		mName(name),
		mStop(false),
		mPeriod(0),
		mPhase(0),
		mReferenceTime(0),
		mWakeupLatency(0) {
		}
		mWakeupLatency(0),
		mFrameNumber(0) {}

		virtual ~DispSyncThread() {}

		void updateModel(nsecs_t period, nsecs_t phase, nsecs_t referenceTime) {
		if (kTraceDetailedInfo) ATRACE_CALL();
		Mutex::Autolock lock(mMutex);
		mPeriod = period;
		mPhase = phase;
		mReferenceTime = referenceTime;
		ALOGV("[%s] updateModel: mPeriod = %" PRId64 ", mPhase = %" PRId64
		" mReferenceTime = %" PRId64, mName, ns2us(mPeriod),
		ns2us(mPhase), ns2us(mReferenceTime));
		mCond.signal();
		}

		void stop() {
		if (kTraceDetailedInfo) ATRACE_CALL();
		Mutex::Autolock lock(mMutex);
		mStop = true;
		mCond.signal();
		@@ -89,6 +107,12 @@ public:
		{ // Scope for lock
		Mutex::Autolock lock(mMutex);

		if (kTraceDetailedInfo) {
		ATRACE_INT64("DispSync:Frame", mFrameNumber);
		}
		ALOGV("[%s] Frame %" PRId64, mName, mFrameNumber);
		++mFrameNumber;

		if (mStop) {
		return false;
		}
		@@ -109,6 +133,9 @@ public:
		bool isWakeup = false;

		if (now < targetTime) {
		ALOGV("[%s] Waiting until %" PRId64, mName,
		ns2us(targetTime));
		if (kTraceDetailedInfo) ATRACE_NAME("DispSync waiting");
		err = mCond.waitRelative(mMutex, targetTime - now);

		if (err == TIMED_OUT) {
		@@ -122,15 +149,15 @@ public:

		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;
		if (mWakeupLatency > 500000) {
		// Don't correct by more than 500 us
		mWakeupLatency = 500000;
		}
		mWakeupLatency = min(mWakeupLatency, kMaxWakeupLatency);
		if (kTraceDetailedInfo) {
		ATRACE_INT64("DispSync:WakeupLat", now - nextEventTime);
		ATRACE_INT64("DispSync:WakeupLat", now - targetTime);
		ATRACE_INT64("DispSync:AvgWakeupLat", mWakeupLatency);
		}
		}
		@@ -146,7 +173,9 @@ public:
		return false;
		}

		status_t addEventListener(nsecs_t phase, const sp<DispSync::Callback>& callback) {
		status_t addEventListener(const char* name, nsecs_t phase,
		const sp<DispSync::Callback>& callback) {
		if (kTraceDetailedInfo) ATRACE_CALL();
		Mutex::Autolock lock(mMutex);

		for (size_t i = 0; i < mEventListeners.size(); i++) {
		@@ -156,15 +185,14 @@ public:
		}

		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. Because
		// computeListenerNextEventTimeLocked filters out events within a half
		// a period of the last event time, we need to initialize the last
		// event time to a half a period in the past.
		listener.mLastEventTime = systemTime(SYSTEM_TIME_MONOTONIC) - mPeriod / 2;
		// allowing any past events to fire
		listener.mLastEventTime = systemTime() - mPeriod / 2 + mPhase -
		mWakeupLatency;

		mEventListeners.push(listener);

		@@ -174,6 +202,7 @@ public:
		}

		status_t removeEventListener(const sp<DispSync::Callback>& callback) {
		if (kTraceDetailedInfo) ATRACE_CALL();
		Mutex::Autolock lock(mMutex);

		for (size_t i = 0; i < mEventListeners.size(); i++) {
		@@ -189,6 +218,7 @@ public:

		// This method is only here to handle the kIgnorePresentFences case.
		bool hasAnyEventListeners() {
		if (kTraceDetailedInfo) ATRACE_CALL();
		Mutex::Autolock lock(mMutex);
		return !mEventListeners.empty();
		}
		@@ -196,6 +226,7 @@ public:
		private:

		struct EventListener {
		const char* mName;
		nsecs_t mPhase;
		nsecs_t mLastEventTime;
		sp<DispSync::Callback> mCallback;
		@@ -207,6 +238,8 @@ private:
		};

		nsecs_t computeNextEventTimeLocked(nsecs_t now) {
		if (kTraceDetailedInfo) 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],
		@@ -217,21 +250,28 @@ private:
		}
		}

		ALOGV("[%s] nextEventTime = %" PRId64, mName, ns2us(nextEventTime));
		return nextEventTime;
		}

		Vector<CallbackInvocation> gatherCallbackInvocationsLocked(nsecs_t now) {
		if (kTraceDetailedInfo) ATRACE_CALL();
		ALOGV("[%s] gatherCallbackInvocationsLocked @ %" PRId64, mName,
		ns2us(now));

		Vector<CallbackInvocation> callbackInvocations;
		nsecs_t ref = now - mPeriod;
		nsecs_t onePeriodAgo = now - mPeriod;

		for (size_t i = 0; i < mEventListeners.size(); i++) {
		nsecs_t t = computeListenerNextEventTimeLocked(mEventListeners[i],
		ref);
		onePeriodAgo);

		if (t < now) {
		CallbackInvocation ci;
		ci.mCallback = mEventListeners[i].mCallback;
		ci.mEventTime = t;
		ALOGV("[%s] [%s] Preparing to fire", mName,
		mEventListeners[i].mName);
		callbackInvocations.push(ci);
		mEventListeners.editItemAt(i).mLastEventTime = t;
		}
		@@ -241,29 +281,67 @@ private:
		}

		nsecs_t computeListenerNextEventTimeLocked(const EventListener& listener,
		nsecs_t ref) {

		nsecs_t lastEventTime = listener.mLastEventTime;
		if (ref < lastEventTime) {
		ref = lastEventTime;
		}

		nsecs_t phase = mReferenceTime + mPhase + listener.mPhase;
		nsecs_t t = (((ref - phase) / mPeriod) + 1) * mPeriod + phase;

		if (t - listener.mLastEventTime < mPeriod / 2) {
		nsecs_t baseTime) {
		if (kTraceDetailedInfo) 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 (t - listener.mLastEventTime < (3 * mPeriod / 5)) {
		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 Vector<CallbackInvocation>& callbacks) {
		if (kTraceDetailedInfo) ATRACE_CALL();
		for (size_t i = 0; i < callbacks.size(); i++) {
		callbacks[i].mCallback->onDispSyncEvent(callbacks[i].mEventTime);
		}
		}

		const char* const mName;

		bool mStop;

		nsecs_t mPeriod;
		@@ -271,12 +349,17 @@ private:
		nsecs_t mReferenceTime;
		nsecs_t mWakeupLatency;

		int64_t mFrameNumber;

		Vector<EventListener> mEventListeners;

		Mutex mMutex;
		Condition mCond;
		};

		#undef LOG_TAG
		#define LOG_TAG "DispSync"

		class ZeroPhaseTracer : public DispSync::Callback {
		public:
		ZeroPhaseTracer() : mParity(false) {}
		@@ -290,9 +373,10 @@ private:
		bool mParity;
		};

		DispSync::DispSync() :
		DispSync::DispSync(const char* name) :
		mName(name),
		mRefreshSkipCount(0),
		mThread(new DispSyncThread()) {
		mThread(new DispSyncThread(name)) {

		mThread->run("DispSync", PRIORITY_URGENT_DISPLAY + PRIORITY_MORE_FAVORABLE);

		@@ -305,8 +389,8 @@ DispSync::DispSync() :
		// Even if we're just ignoring the fences, the zero-phase tracing is
		// not needed because any time there is an event registered we will
		// turn on the HW vsync events.
		if (!kIgnorePresentFences) {
		addEventListener(0, new ZeroPhaseTracer());
		if (!kIgnorePresentFences && kEnableZeroPhaseTracer) {
		addEventListener("ZeroPhaseTracer", 0, new ZeroPhaseTracer());
		}
		}
		}
		@@ -351,7 +435,7 @@ bool DispSync::addPresentFence(const sp<Fence>& fence) {

		void DispSync::beginResync() {
		Mutex::Autolock lock(mMutex);

		ALOGV("[%s] beginResync", mName);
		mModelUpdated = false;
		mNumResyncSamples = 0;
		}
		@@ -359,11 +443,17 @@ void DispSync::beginResync() {
		bool DispSync::addResyncSample(nsecs_t timestamp) {
		Mutex::Autolock lock(mMutex);

		ALOGV("[%s] addResyncSample(%" PRId64 ")", mName, ns2us(timestamp));

		size_t idx = (mFirstResyncSample + mNumResyncSamples) % MAX_RESYNC_SAMPLES;
		mResyncSamples[idx] = timestamp;
		if (mNumResyncSamples == 0) {
		mPhase = 0;
		mReferenceTime = timestamp;
		ALOGV("[%s] First resync sample: mPeriod = %" PRId64 ", mPhase = 0, "
		"mReferenceTime = %" PRId64, mName, ns2us(mPeriod),
		ns2us(mReferenceTime));
		mThread->updateModel(mPeriod, mPhase, mReferenceTime);
		}

		if (mNumResyncSamples < MAX_RESYNC_SAMPLES) {
		@@ -387,17 +477,21 @@ bool DispSync::addResyncSample(nsecs_t timestamp) {
		return mThread->hasAnyEventListeners();
		}

		return !mModelUpdated \|\| mError > kErrorThreshold;
		// Check against kErrorThreshold / 2 to add some hysteresis before having to
		// resync again
		bool modelLocked = mModelUpdated && mError < (kErrorThreshold / 2);
		ALOGV("[%s] addResyncSample returning %s", mName,
		modelLocked ? "locked" : "unlocked");
		return !modelLocked;
		}

		void DispSync::endResync() {
		}

		status_t DispSync::addEventListener(nsecs_t phase,
		status_t DispSync::addEventListener(const char* name, nsecs_t phase,
		const sp<Callback>& callback) {

		Mutex::Autolock lock(mMutex);
		return mThread->addEventListener(phase, callback);
		return mThread->addEventListener(name, phase, callback);
		}

		void DispSync::setRefreshSkipCount(int count) {
		@@ -427,20 +521,32 @@ nsecs_t DispSync::getPeriod() {
		}

		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;
		durationSum += mResyncSamples[idx] - mResyncSamples[prev];
		nsecs_t duration = mResyncSamples[idx] - mResyncSamples[prev];
		durationSum += duration;
		minDuration = min(minDuration, duration);
		maxDuration = max(maxDuration, duration);
		}

		mPeriod = durationSum / (mNumResyncSamples - 1);
		// 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);
		for (size_t i = 0; i < mNumResyncSamples; i++) {
		// 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;
		@@ -448,18 +554,21 @@ void DispSync::updateModelLocked() {
		sampleAvgY += sin(samplePhase);
		}

		sampleAvgX /= double(mNumResyncSamples);
		sampleAvgY /= double(mNumResyncSamples);
		sampleAvgX /= double(mNumResyncSamples - 1);
		sampleAvgY /= double(mNumResyncSamples - 1);

		mPhase = nsecs_t(atan2(sampleAvgY, sampleAvgX) / scale);

		if (mPhase < 0) {
		ALOGV("[%s] mPhase = %" PRId64, mName, ns2us(mPhase));

		if (mPhase < -(mPeriod / 2)) {
		mPhase += mPeriod;
		ALOGV("[%s] Adjusting mPhase -> %" PRId64, mName, ns2us(mPhase));
		}

		if (kTraceDetailedInfo) {
		ATRACE_INT64("DispSync:Period", mPeriod);
		ATRACE_INT64("DispSync:Phase", mPhase);
		ATRACE_INT64("DispSync:Phase", mPhase + mPeriod / 2);
		}

		// Artificially inflate the period if requested.

services/surfaceflinger/DispSync.h

+8 −8

Original line number	Diff line number	Diff line
		@@ -26,11 +26,8 @@
		namespace android {

		// Ignore present (retire) fences if the device doesn't have support for the
		// sync framework, or if all phase offsets are zero. The latter is useful
		// because it allows us to avoid resync bursts on devices that don't need
		// phase-offset VSYNC events.
		#if defined(RUNNING_WITHOUT_SYNC_FRAMEWORK) \|\| \
		(VSYNC_EVENT_PHASE_OFFSET_NS == 0 && SF_VSYNC_EVENT_PHASE_OFFSET_NS == 0)
		// sync framework
		#if defined(RUNNING_WITHOUT_SYNC_FRAMEWORK)
		static const bool kIgnorePresentFences = true;
		#else
		static const bool kIgnorePresentFences = false;
		@@ -64,7 +61,7 @@ public:
		virtual void onDispSyncEvent(nsecs_t when) = 0;
		};

		DispSync();
		DispSync(const char* name);
		~DispSync();

		// reset clears the resync samples and error value.
		@@ -114,7 +111,8 @@ public:
		// given phase offset from the hardware vsync events. The callback is
		// called from a separate thread and it should return reasonably quickly
		// (i.e. within a few hundred microseconds).
		status_t addEventListener(nsecs_t phase, const sp<Callback>& callback);
		status_t addEventListener(const char* name, nsecs_t phase,
		const sp<Callback>& callback);

		// removeEventListener removes an already-registered event callback. Once
		// this method returns that callback will no longer be called by the
		@@ -137,10 +135,12 @@ private:
		void resetErrorLocked();

		enum { MAX_RESYNC_SAMPLES = 32 };
		enum { MIN_RESYNC_SAMPLES_FOR_UPDATE = 3 };
		enum { MIN_RESYNC_SAMPLES_FOR_UPDATE = 6 };
		enum { NUM_PRESENT_SAMPLES = 8 };
		enum { MAX_RESYNC_SAMPLES_WITHOUT_PRESENT = 4 };

		const char* const mName;

		// mPeriod is the computed period of the modeled vsync events in
		// nanoseconds.
		nsecs_t mPeriod;

services/surfaceflinger/EventThread.cpp

+5 −1

Original line number	Diff line number	Diff line
		@@ -44,8 +44,9 @@ static void vsyncOffCallback(union sigval val) {
		return;
		}

		EventThread::EventThread(const sp<VSyncSource>& src)
		EventThread::EventThread(const sp<VSyncSource>& src, SurfaceFlinger& flinger)
		: mVSyncSource(src),
		mFlinger(flinger),
		mUseSoftwareVSync(false),
		mVsyncEnabled(false),
		mDebugVsyncEnabled(false),
		@@ -126,6 +127,9 @@ void EventThread::setVsyncRate(uint32_t count,
		void EventThread::requestNextVsync(
		const sp<EventThread::Connection>& connection) {
		Mutex::Autolock _l(mLock);

		mFlinger.resyncWithRateLimit();

		if (connection->count < 0) {
		connection->count = 0;
		mCondition.broadcast();

services/surfaceflinger/EventThread.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -77,7 +77,7 @@ class EventThread : public Thread, private VSyncSource::Callback {

		public:

		EventThread(const sp<VSyncSource>& src);
		EventThread(const sp<VSyncSource>& src, SurfaceFlinger& flinger);

		sp<Connection> createEventConnection() const;
		status_t registerDisplayEventConnection(const sp<Connection>& connection);
		@@ -116,6 +116,7 @@ private:
		// constants
		sp<VSyncSource> mVSyncSource;
		PowerHAL mPowerHAL;
		SurfaceFlinger& mFlinger;

		mutable Mutex mLock;
		mutable Condition mCondition;

services/surfaceflinger/SurfaceFlinger.cpp

+18 −7

Original line number	Diff line number	Diff line
		@@ -149,6 +149,7 @@ SurfaceFlinger::SurfaceFlinger()
		mLastTransactionTime(0),
		mBootFinished(false),
		mForceFullDamage(false),
		mPrimaryDispSync("PrimaryDispSync"),
		mPrimaryHWVsyncEnabled(false),
		mHWVsyncAvailable(false),
		mDaltonize(false),
		@@ -331,11 +332,12 @@ void SurfaceFlinger::deleteTextureAsync(uint32_t texture) {
		class DispSyncSource : public VSyncSource, private DispSync::Callback {
		public:
		DispSyncSource(DispSync* dispSync, nsecs_t phaseOffset, bool traceVsync,
		const char* label) :
		const char* name) :
		mName(name),
		mValue(0),
		mTraceVsync(traceVsync),
		mVsyncOnLabel(String8::format("VsyncOn-%s", label)),
		mVsyncEventLabel(String8::format("VSYNC-%s", label)),
		mVsyncOnLabel(String8::format("VsyncOn-%s", name)),
		mVsyncEventLabel(String8::format("VSYNC-%s", name)),
		mDispSync(dispSync),
		mCallbackMutex(),
		mCallback(),
		@@ -348,7 +350,7 @@ public:
		virtual void setVSyncEnabled(bool enable) {
		Mutex::Autolock lock(mVsyncMutex);
		if (enable) {
		status_t err = mDispSync->addEventListener(mPhaseOffset,
		status_t err = mDispSync->addEventListener(mName, mPhaseOffset,
		static_cast<DispSync::Callback*>(this));
		if (err != NO_ERROR) {
		ALOGE("error registering vsync callback: %s (%d)",
		@@ -399,7 +401,7 @@ public:
		}

		// Add a listener with the new offset
		err = mDispSync->addEventListener(mPhaseOffset,
		err = mDispSync->addEventListener(mName, mPhaseOffset,
		static_cast<DispSync::Callback*>(this));
		if (err != NO_ERROR) {
		ALOGE("error registering vsync callback: %s (%d)",
		@@ -425,6 +427,8 @@ private:
		}
		}

		const char* const mName;

		int mValue;

		const bool mTraceVsync;
		@@ -455,10 +459,10 @@ void SurfaceFlinger::init() {
		// start the EventThread
		sp<VSyncSource> vsyncSrc = new DispSyncSource(&mPrimaryDispSync,
		vsyncPhaseOffsetNs, true, "app");
		mEventThread = new EventThread(vsyncSrc);
		mEventThread = new EventThread(vsyncSrc, *this);
		sp<VSyncSource> sfVsyncSrc = new DispSyncSource(&mPrimaryDispSync,
		sfVsyncPhaseOffsetNs, true, "sf");
		mSFEventThread = new EventThread(sfVsyncSrc);
		mSFEventThread = new EventThread(sfVsyncSrc, *this);
		mEventQueue.setEventThread(mSFEventThread);

		// Get a RenderEngine for the given display / config (can't fail)
		@@ -827,6 +831,13 @@ void SurfaceFlinger::disableHardwareVsync(bool makeUnavailable) {
		}
		}

		void SurfaceFlinger::resyncWithRateLimit() {
		static constexpr nsecs_t kIgnoreDelay = ms2ns(500);
		if (systemTime() - mLastSwapTime > kIgnoreDelay) {
		resyncToHardwareVsync(true);
		}
		}

		void SurfaceFlinger::onVSyncReceived(int32_t type, nsecs_t timestamp) {
		bool needsHwVsync = false;