void InputReader::loopOnce() {
    int32_t oldGeneration;
    int32_t timeoutMillis;
    bool inputDevicesChanged = false;
    Vector<InputDeviceInfo> inputDevices;
    { // acquire lock
        AutoMutex _l(mLock);
        oldGeneration = mGeneration;
        timeoutMillis = -1;
        uint32_t changes = mConfigurationChangesToRefresh;
        if (changes) {
            mConfigurationChangesToRefresh = 0;
            timeoutMillis = 0;
            refreshConfigurationLocked(changes);
        } else if (mNextTimeout != LLONG_MAX) {
            nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
            timeoutMillis = toMillisecondTimeoutDelay(now, mNextTimeout);
        }
    } // release lock
    size_t count = mEventHub->getEvents(timeoutMillis, mEventBuffer, EVENT_BUFFER_SIZE);
    { // acquire lock
        AutoMutex _l(mLock);
        mReaderIsAliveCondition.broadcast();
        if (count) {
            processEventsLocked(mEventBuffer, count);
        }
        if (mNextTimeout != LLONG_MAX) {
            nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
            if (now >= mNextTimeout) {
#if DEBUG_RAW_EVENTS
                ALOGD("Timeout expired, latency=%0.3fms", (now - mNextTimeout) * 0.000001f);
#endif
                mNextTimeout = LLONG_MAX;
                timeoutExpiredLocked(now);
            }
        }
        if (oldGeneration != mGeneration) {
            inputDevicesChanged = true;
            getInputDevicesLocked(inputDevices);
        }
    } // release lock
    // Send out a message that the describes the changed input devices.
    if (inputDevicesChanged) {
        mPolicy->notifyInputDevicesChanged(inputDevices);
    }
    // Flush queued events out to the listener.
    // This must happen outside of the lock because the listener could potentially call
    // back into the InputReader's methods, such as getScanCodeState, or become blocked
    // on another thread similarly waiting to acquire the InputReader lock thereby
    // resulting in a deadlock.  This situation is actually quite plausible because the
    // listener is actually the input dispatcher, which calls into the window manager,
    // which occasionally calls into the input reader.
    mQueuedListener->flush();
}

依次调用方法

void TouchInputMapper::process(const RawEvent* rawEvent)
void TouchInputMapper::sync(nsecs_t when)
void TouchInputMapper::processRawTouches(bool timeout)
void TouchInputMapper::cookAndDispatch(nsecs_t when)
void TouchInputMapper::dispatchTouches(nsecs_t when, uint32_t policyFlags)
void TouchInputMapper::dispatchMotion(nsecs_t when, uint32_t policyFlags, uint32_t source,
int32_t action, int32_t actionButton, int32_t flags,
int32_t metaState, int32_t buttonState, int32_t edgeFlags,
const PointerProperties* properties, const PointerCoords* coords,
const uint32_t* idToIndex, BitSet32 idBits, int32_t changedId,
float xPrecision, float yPrecision, nsecs_t downTime)

void TouchInputMapper::dispatchMotion(nsecs_t when, uint32_t policyFlags, uint32_t source,
        int32_t action, int32_t actionButton, int32_t flags,
        int32_t metaState, int32_t buttonState, int32_t edgeFlags,
        const PointerProperties* properties, const PointerCoords* coords,
        const uint32_t* idToIndex, BitSet32 idBits, int32_t changedId,
        float xPrecision, float yPrecision, nsecs_t downTime) {
    PointerCoords pointerCoords[MAX_POINTERS];
    PointerProperties pointerProperties[MAX_POINTERS];
    uint32_t pointerCount = 0;
    while (!idBits.isEmpty()) {
        uint32_t id = idBits.clearFirstMarkedBit();
        uint32_t index = idToIndex[id];
        pointerProperties[pointerCount].copyFrom(properties[index]);
        pointerCoords[pointerCount].copyFrom(coords[index]);

        if (changedId >= 0 && id == uint32_t(changedId)) {
            action |= pointerCount << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
        }

        pointerCount += 1;
    }

    ALOG_ASSERT(pointerCount != 0);

    if (changedId >= 0 && pointerCount == 1) {
        // Replace initial down and final up action.
        // We can compare the action without masking off the changed pointer index
        // because we know the index is 0.
        if (action == AMOTION_EVENT_ACTION_POINTER_DOWN) {
            action = AMOTION_EVENT_ACTION_DOWN;
        } else if (action == AMOTION_EVENT_ACTION_POINTER_UP) {
            action = AMOTION_EVENT_ACTION_UP;
        } else {
            // Can't happen.
            ALOG_ASSERT(false);
        }
    }

    NotifyMotionArgs args(when, getDeviceId(), source, policyFlags,
            action, actionButton, flags, metaState, buttonState, edgeFlags,
            mViewport.displayId, pointerCount, pointerProperties, pointerCoords,
            xPrecision, yPrecision, downTime);
    getListener()->notifyMotion(&args);
}
InputListenerInterface* InputReader::ContextImpl::getListener() {
    return mReader->mQueuedListener.get();
}
InputReader::InputReader(const sp<EventHubInterface>& eventHub,
        const sp<InputReaderPolicyInterface>& policy,
        const sp<InputListenerInterface>& lis