Merge "When adding event listener, use fuzzy window for last event time."

            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;

            listener.mLastEventTime = predictedReference + phaseCorrection;

            // If we're very close in time to the predicted last event time,

            // then we need to back up the last event time so that we can

            // attempt to fire an event immediately.

            //

            // Otherwise, keep the last event time that we predicted.

            if (isShorterThanPeriod(now - listener.mLastEventTime)) {

                listener.mLastEventTime -= mPeriod;

            }

        } else {

            listener.mLastEventTime = now + mPhase - mWakeupLatency;

    // Sanity check that the duration is close enough in length to a period without

    // falling into double-rate vsyncs.

    bool isCloseToPeriod(nsecs_t duration) {

    bool isShorterThanPeriod(nsecs_t duration) {

        // Ratio of 3/5 is arbitrary, but it must be greater than 1/2.

        return duration < (3 * mPeriod) / 5;

    }

            nsecs_t t = computeListenerNextEventTimeLocked(eventListener, onePeriodAgo);

            if (t < now) {

                if (isCloseToPeriod(now - eventListener.mLastCallbackTime)) {

                if (isShorterThanPeriod(now - eventListener.mLastCallbackTime)) {

                    eventListener.mLastEventTime = t;

                    eventListener.mLastCallbackTime = now;

                    ALOGV("[%s] [%s] Skipping event due to model error", mName,

        // 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)) {

        if (isShorterThanPeriod(t - listener.mLastEventTime)) {

            t += mPeriod;

            ALOGV("[%s] Modifying t -> %" PRId64, mName, ns2us(t));

        }