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      1 //
      2 // Copyright 2010 The Android Open Source Project
      3 //
      4 // Provides a shared memory transport for input events.
      5 //
      6 #define LOG_TAG "InputTransport"
      7 
      8 //#define LOG_NDEBUG 0
      9 
     10 // Log debug messages about channel messages (send message, receive message)
     11 #define DEBUG_CHANNEL_MESSAGES 0
     12 
     13 // Log debug messages whenever InputChannel objects are created/destroyed
     14 #define DEBUG_CHANNEL_LIFECYCLE 0
     15 
     16 // Log debug messages about transport actions
     17 #define DEBUG_TRANSPORT_ACTIONS 0
     18 
     19 // Log debug messages about touch event resampling
     20 #define DEBUG_RESAMPLING 0
     21 
     22 
     23 #include <errno.h>
     24 #include <fcntl.h>
     25 #include <math.h>
     26 #include <sys/types.h>
     27 #include <sys/socket.h>
     28 #include <unistd.h>
     29 
     30 #include <cutils/log.h>
     31 #include <cutils/properties.h>
     32 #include <input/InputTransport.h>
     33 
     34 
     35 namespace android {
     36 
     37 // Socket buffer size.  The default is typically about 128KB, which is much larger than
     38 // we really need.  So we make it smaller.  It just needs to be big enough to hold
     39 // a few dozen large multi-finger motion events in the case where an application gets
     40 // behind processing touches.
     41 static const size_t SOCKET_BUFFER_SIZE = 32 * 1024;
     42 
     43 // Nanoseconds per milliseconds.
     44 static const nsecs_t NANOS_PER_MS = 1000000;
     45 
     46 // Latency added during resampling.  A few milliseconds doesn't hurt much but
     47 // reduces the impact of mispredicted touch positions.
     48 static const nsecs_t RESAMPLE_LATENCY = 5 * NANOS_PER_MS;
     49 
     50 // Minimum time difference between consecutive samples before attempting to resample.
     51 static const nsecs_t RESAMPLE_MIN_DELTA = 2 * NANOS_PER_MS;
     52 
     53 // Maximum time to predict forward from the last known state, to avoid predicting too
     54 // far into the future.  This time is further bounded by 50% of the last time delta.
     55 static const nsecs_t RESAMPLE_MAX_PREDICTION = 8 * NANOS_PER_MS;
     56 
     57 template<typename T>
     58 inline static T min(const T& a, const T& b) {
     59     return a < b ? a : b;
     60 }
     61 
     62 inline static float lerp(float a, float b, float alpha) {
     63     return a + alpha * (b - a);
     64 }
     65 
     66 // --- InputMessage ---
     67 
     68 bool InputMessage::isValid(size_t actualSize) const {
     69     if (size() == actualSize) {
     70         switch (header.type) {
     71         case TYPE_KEY:
     72             return true;
     73         case TYPE_MOTION:
     74             return body.motion.pointerCount > 0
     75                     && body.motion.pointerCount <= MAX_POINTERS;
     76         case TYPE_FINISHED:
     77             return true;
     78         }
     79     }
     80     return false;
     81 }
     82 
     83 size_t InputMessage::size() const {
     84     switch (header.type) {
     85     case TYPE_KEY:
     86         return sizeof(Header) + body.key.size();
     87     case TYPE_MOTION:
     88         return sizeof(Header) + body.motion.size();
     89     case TYPE_FINISHED:
     90         return sizeof(Header) + body.finished.size();
     91     }
     92     return sizeof(Header);
     93 }
     94 
     95 
     96 // --- InputChannel ---
     97 
     98 InputChannel::InputChannel(const String8& name, int fd) :
     99         mName(name), mFd(fd) {
    100 #if DEBUG_CHANNEL_LIFECYCLE
    101     ALOGD("Input channel constructed: name='%s', fd=%d",
    102             mName.string(), fd);
    103 #endif
    104 
    105     int result = fcntl(mFd, F_SETFL, O_NONBLOCK);
    106     LOG_ALWAYS_FATAL_IF(result != 0, "channel '%s' ~ Could not make socket "
    107             "non-blocking.  errno=%d", mName.string(), errno);
    108 }
    109 
    110 InputChannel::~InputChannel() {
    111 #if DEBUG_CHANNEL_LIFECYCLE
    112     ALOGD("Input channel destroyed: name='%s', fd=%d",
    113             mName.string(), mFd);
    114 #endif
    115 
    116     ::close(mFd);
    117 }
    118 
    119 status_t InputChannel::openInputChannelPair(const String8& name,
    120         sp<InputChannel>& outServerChannel, sp<InputChannel>& outClientChannel) {
    121     int sockets[2];
    122     if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets)) {
    123         status_t result = -errno;
    124         ALOGE("channel '%s' ~ Could not create socket pair.  errno=%d",
    125                 name.string(), errno);
    126         outServerChannel.clear();
    127         outClientChannel.clear();
    128         return result;
    129     }
    130 
    131     int bufferSize = SOCKET_BUFFER_SIZE;
    132     setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
    133     setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
    134     setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
    135     setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
    136 
    137     String8 serverChannelName = name;
    138     serverChannelName.append(" (server)");
    139     outServerChannel = new InputChannel(serverChannelName, sockets[0]);
    140 
    141     String8 clientChannelName = name;
    142     clientChannelName.append(" (client)");
    143     outClientChannel = new InputChannel(clientChannelName, sockets[1]);
    144     return OK;
    145 }
    146 
    147 status_t InputChannel::sendMessage(const InputMessage* msg) {
    148     size_t msgLength = msg->size();
    149     ssize_t nWrite;
    150     do {
    151         nWrite = ::send(mFd, msg, msgLength, MSG_DONTWAIT | MSG_NOSIGNAL);
    152     } while (nWrite == -1 && errno == EINTR);
    153 
    154     if (nWrite < 0) {
    155         int error = errno;
    156 #if DEBUG_CHANNEL_MESSAGES
    157         ALOGD("channel '%s' ~ error sending message of type %d, errno=%d", mName.string(),
    158                 msg->header.type, error);
    159 #endif
    160         if (error == EAGAIN || error == EWOULDBLOCK) {
    161             return WOULD_BLOCK;
    162         }
    163         if (error == EPIPE || error == ENOTCONN || error == ECONNREFUSED || error == ECONNRESET) {
    164             return DEAD_OBJECT;
    165         }
    166         return -error;
    167     }
    168 
    169     if (size_t(nWrite) != msgLength) {
    170 #if DEBUG_CHANNEL_MESSAGES
    171         ALOGD("channel '%s' ~ error sending message type %d, send was incomplete",
    172                 mName.string(), msg->header.type);
    173 #endif
    174         return DEAD_OBJECT;
    175     }
    176 
    177 #if DEBUG_CHANNEL_MESSAGES
    178     ALOGD("channel '%s' ~ sent message of type %d", mName.string(), msg->header.type);
    179 #endif
    180     return OK;
    181 }
    182 
    183 status_t InputChannel::receiveMessage(InputMessage* msg) {
    184     ssize_t nRead;
    185     do {
    186         nRead = ::recv(mFd, msg, sizeof(InputMessage), MSG_DONTWAIT);
    187     } while (nRead == -1 && errno == EINTR);
    188 
    189     if (nRead < 0) {
    190         int error = errno;
    191 #if DEBUG_CHANNEL_MESSAGES
    192         ALOGD("channel '%s' ~ receive message failed, errno=%d", mName.string(), errno);
    193 #endif
    194         if (error == EAGAIN || error == EWOULDBLOCK) {
    195             return WOULD_BLOCK;
    196         }
    197         if (error == EPIPE || error == ENOTCONN || error == ECONNREFUSED) {
    198             return DEAD_OBJECT;
    199         }
    200         return -error;
    201     }
    202 
    203     if (nRead == 0) { // check for EOF
    204 #if DEBUG_CHANNEL_MESSAGES
    205         ALOGD("channel '%s' ~ receive message failed because peer was closed", mName.string());
    206 #endif
    207         return DEAD_OBJECT;
    208     }
    209 
    210     if (!msg->isValid(nRead)) {
    211 #if DEBUG_CHANNEL_MESSAGES
    212         ALOGD("channel '%s' ~ received invalid message", mName.string());
    213 #endif
    214         return BAD_VALUE;
    215     }
    216 
    217 #if DEBUG_CHANNEL_MESSAGES
    218     ALOGD("channel '%s' ~ received message of type %d", mName.string(), msg->header.type);
    219 #endif
    220     return OK;
    221 }
    222 
    223 sp<InputChannel> InputChannel::dup() const {
    224     int fd = ::dup(getFd());
    225     return fd >= 0 ? new InputChannel(getName(), fd) : NULL;
    226 }
    227 
    228 
    229 // --- InputPublisher ---
    230 
    231 InputPublisher::InputPublisher(const sp<InputChannel>& channel) :
    232         mChannel(channel) {
    233 }
    234 
    235 InputPublisher::~InputPublisher() {
    236 }
    237 
    238 status_t InputPublisher::publishKeyEvent(
    239         uint32_t seq,
    240         int32_t deviceId,
    241         int32_t source,
    242         int32_t action,
    243         int32_t flags,
    244         int32_t keyCode,
    245         int32_t scanCode,
    246         int32_t metaState,
    247         int32_t repeatCount,
    248         nsecs_t downTime,
    249         nsecs_t eventTime) {
    250 #if DEBUG_TRANSPORT_ACTIONS
    251     ALOGD("channel '%s' publisher ~ publishKeyEvent: seq=%u, deviceId=%d, source=0x%x, "
    252             "action=0x%x, flags=0x%x, keyCode=%d, scanCode=%d, metaState=0x%x, repeatCount=%d,"
    253             "downTime=%lld, eventTime=%lld",
    254             mChannel->getName().string(), seq,
    255             deviceId, source, action, flags, keyCode, scanCode, metaState, repeatCount,
    256             downTime, eventTime);
    257 #endif
    258 
    259     if (!seq) {
    260         ALOGE("Attempted to publish a key event with sequence number 0.");
    261         return BAD_VALUE;
    262     }
    263 
    264     InputMessage msg;
    265     msg.header.type = InputMessage::TYPE_KEY;
    266     msg.body.key.seq = seq;
    267     msg.body.key.deviceId = deviceId;
    268     msg.body.key.source = source;
    269     msg.body.key.action = action;
    270     msg.body.key.flags = flags;
    271     msg.body.key.keyCode = keyCode;
    272     msg.body.key.scanCode = scanCode;
    273     msg.body.key.metaState = metaState;
    274     msg.body.key.repeatCount = repeatCount;
    275     msg.body.key.downTime = downTime;
    276     msg.body.key.eventTime = eventTime;
    277     return mChannel->sendMessage(&msg);
    278 }
    279 
    280 status_t InputPublisher::publishMotionEvent(
    281         uint32_t seq,
    282         int32_t deviceId,
    283         int32_t source,
    284         int32_t action,
    285         int32_t flags,
    286         int32_t edgeFlags,
    287         int32_t metaState,
    288         int32_t buttonState,
    289         float xOffset,
    290         float yOffset,
    291         float xPrecision,
    292         float yPrecision,
    293         nsecs_t downTime,
    294         nsecs_t eventTime,
    295         size_t pointerCount,
    296         const PointerProperties* pointerProperties,
    297         const PointerCoords* pointerCoords) {
    298 #if DEBUG_TRANSPORT_ACTIONS
    299     ALOGD("channel '%s' publisher ~ publishMotionEvent: seq=%u, deviceId=%d, source=0x%x, "
    300             "action=0x%x, flags=0x%x, edgeFlags=0x%x, metaState=0x%x, buttonState=0x%x, "
    301             "xOffset=%f, yOffset=%f, "
    302             "xPrecision=%f, yPrecision=%f, downTime=%lld, eventTime=%lld, "
    303             "pointerCount=%d",
    304             mChannel->getName().string(), seq,
    305             deviceId, source, action, flags, edgeFlags, metaState, buttonState,
    306             xOffset, yOffset, xPrecision, yPrecision, downTime, eventTime, pointerCount);
    307 #endif
    308 
    309     if (!seq) {
    310         ALOGE("Attempted to publish a motion event with sequence number 0.");
    311         return BAD_VALUE;
    312     }
    313 
    314     if (pointerCount > MAX_POINTERS || pointerCount < 1) {
    315         ALOGE("channel '%s' publisher ~ Invalid number of pointers provided: %d.",
    316                 mChannel->getName().string(), pointerCount);
    317         return BAD_VALUE;
    318     }
    319 
    320     InputMessage msg;
    321     msg.header.type = InputMessage::TYPE_MOTION;
    322     msg.body.motion.seq = seq;
    323     msg.body.motion.deviceId = deviceId;
    324     msg.body.motion.source = source;
    325     msg.body.motion.action = action;
    326     msg.body.motion.flags = flags;
    327     msg.body.motion.edgeFlags = edgeFlags;
    328     msg.body.motion.metaState = metaState;
    329     msg.body.motion.buttonState = buttonState;
    330     msg.body.motion.xOffset = xOffset;
    331     msg.body.motion.yOffset = yOffset;
    332     msg.body.motion.xPrecision = xPrecision;
    333     msg.body.motion.yPrecision = yPrecision;
    334     msg.body.motion.downTime = downTime;
    335     msg.body.motion.eventTime = eventTime;
    336     msg.body.motion.pointerCount = pointerCount;
    337     for (size_t i = 0; i < pointerCount; i++) {
    338         msg.body.motion.pointers[i].properties.copyFrom(pointerProperties[i]);
    339         msg.body.motion.pointers[i].coords.copyFrom(pointerCoords[i]);
    340     }
    341     return mChannel->sendMessage(&msg);
    342 }
    343 
    344 status_t InputPublisher::receiveFinishedSignal(uint32_t* outSeq, bool* outHandled) {
    345 #if DEBUG_TRANSPORT_ACTIONS
    346     ALOGD("channel '%s' publisher ~ receiveFinishedSignal",
    347             mChannel->getName().string());
    348 #endif
    349 
    350     InputMessage msg;
    351     status_t result = mChannel->receiveMessage(&msg);
    352     if (result) {
    353         *outSeq = 0;
    354         *outHandled = false;
    355         return result;
    356     }
    357     if (msg.header.type != InputMessage::TYPE_FINISHED) {
    358         ALOGE("channel '%s' publisher ~ Received unexpected message of type %d from consumer",
    359                 mChannel->getName().string(), msg.header.type);
    360         return UNKNOWN_ERROR;
    361     }
    362     *outSeq = msg.body.finished.seq;
    363     *outHandled = msg.body.finished.handled;
    364     return OK;
    365 }
    366 
    367 // --- InputConsumer ---
    368 
    369 InputConsumer::InputConsumer(const sp<InputChannel>& channel) :
    370         mResampleTouch(isTouchResamplingEnabled()),
    371         mChannel(channel), mMsgDeferred(false) {
    372 }
    373 
    374 InputConsumer::~InputConsumer() {
    375 }
    376 
    377 bool InputConsumer::isTouchResamplingEnabled() {
    378     char value[PROPERTY_VALUE_MAX];
    379     int length = property_get("ro.input.noresample", value, NULL);
    380     if (length > 0) {
    381         if (!strcmp("1", value)) {
    382             return false;
    383         }
    384         if (strcmp("0", value)) {
    385             ALOGD("Unrecognized property value for 'ro.input.noresample'.  "
    386                     "Use '1' or '0'.");
    387         }
    388     }
    389     return true;
    390 }
    391 
    392 status_t InputConsumer::consume(InputEventFactoryInterface* factory,
    393         bool consumeBatches, nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent) {
    394 #if DEBUG_TRANSPORT_ACTIONS
    395     ALOGD("channel '%s' consumer ~ consume: consumeBatches=%s, frameTime=%lld",
    396             mChannel->getName().string(), consumeBatches ? "true" : "false", frameTime);
    397 #endif
    398 
    399     *outSeq = 0;
    400     *outEvent = NULL;
    401 
    402     // Fetch the next input message.
    403     // Loop until an event can be returned or no additional events are received.
    404     while (!*outEvent) {
    405         if (mMsgDeferred) {
    406             // mMsg contains a valid input message from the previous call to consume
    407             // that has not yet been processed.
    408             mMsgDeferred = false;
    409         } else {
    410             // Receive a fresh message.
    411             status_t result = mChannel->receiveMessage(&mMsg);
    412             if (result) {
    413                 // Consume the next batched event unless batches are being held for later.
    414                 if (consumeBatches || result != WOULD_BLOCK) {
    415                     result = consumeBatch(factory, frameTime, outSeq, outEvent);
    416                     if (*outEvent) {
    417 #if DEBUG_TRANSPORT_ACTIONS
    418                         ALOGD("channel '%s' consumer ~ consumed batch event, seq=%u",
    419                                 mChannel->getName().string(), *outSeq);
    420 #endif
    421                         break;
    422                     }
    423                 }
    424                 return result;
    425             }
    426         }
    427 
    428         switch (mMsg.header.type) {
    429         case InputMessage::TYPE_KEY: {
    430             KeyEvent* keyEvent = factory->createKeyEvent();
    431             if (!keyEvent) return NO_MEMORY;
    432 
    433             initializeKeyEvent(keyEvent, &mMsg);
    434             *outSeq = mMsg.body.key.seq;
    435             *outEvent = keyEvent;
    436 #if DEBUG_TRANSPORT_ACTIONS
    437             ALOGD("channel '%s' consumer ~ consumed key event, seq=%u",
    438                     mChannel->getName().string(), *outSeq);
    439 #endif
    440             break;
    441         }
    442 
    443         case AINPUT_EVENT_TYPE_MOTION: {
    444             ssize_t batchIndex = findBatch(mMsg.body.motion.deviceId, mMsg.body.motion.source);
    445             if (batchIndex >= 0) {
    446                 Batch& batch = mBatches.editItemAt(batchIndex);
    447                 if (canAddSample(batch, &mMsg)) {
    448                     batch.samples.push(mMsg);
    449 #if DEBUG_TRANSPORT_ACTIONS
    450                     ALOGD("channel '%s' consumer ~ appended to batch event",
    451                             mChannel->getName().string());
    452 #endif
    453                     break;
    454                 } else {
    455                     // We cannot append to the batch in progress, so we need to consume
    456                     // the previous batch right now and defer the new message until later.
    457                     mMsgDeferred = true;
    458                     status_t result = consumeSamples(factory,
    459                             batch, batch.samples.size(), outSeq, outEvent);
    460                     mBatches.removeAt(batchIndex);
    461                     if (result) {
    462                         return result;
    463                     }
    464 #if DEBUG_TRANSPORT_ACTIONS
    465                     ALOGD("channel '%s' consumer ~ consumed batch event and "
    466                             "deferred current event, seq=%u",
    467                             mChannel->getName().string(), *outSeq);
    468 #endif
    469                     break;
    470                 }
    471             }
    472 
    473             // Start a new batch if needed.
    474             if (mMsg.body.motion.action == AMOTION_EVENT_ACTION_MOVE
    475                     || mMsg.body.motion.action == AMOTION_EVENT_ACTION_HOVER_MOVE) {
    476                 mBatches.push();
    477                 Batch& batch = mBatches.editTop();
    478                 batch.samples.push(mMsg);
    479 #if DEBUG_TRANSPORT_ACTIONS
    480                 ALOGD("channel '%s' consumer ~ started batch event",
    481                         mChannel->getName().string());
    482 #endif
    483                 break;
    484             }
    485 
    486             MotionEvent* motionEvent = factory->createMotionEvent();
    487             if (! motionEvent) return NO_MEMORY;
    488 
    489             updateTouchState(&mMsg);
    490             initializeMotionEvent(motionEvent, &mMsg);
    491             *outSeq = mMsg.body.motion.seq;
    492             *outEvent = motionEvent;
    493 #if DEBUG_TRANSPORT_ACTIONS
    494             ALOGD("channel '%s' consumer ~ consumed motion event, seq=%u",
    495                     mChannel->getName().string(), *outSeq);
    496 #endif
    497             break;
    498         }
    499 
    500         default:
    501             ALOGE("channel '%s' consumer ~ Received unexpected message of type %d",
    502                     mChannel->getName().string(), mMsg.header.type);
    503             return UNKNOWN_ERROR;
    504         }
    505     }
    506     return OK;
    507 }
    508 
    509 status_t InputConsumer::consumeBatch(InputEventFactoryInterface* factory,
    510         nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent) {
    511     status_t result;
    512     for (size_t i = mBatches.size(); i-- > 0; ) {
    513         Batch& batch = mBatches.editItemAt(i);
    514         if (frameTime < 0 || !mResampleTouch) {
    515             result = consumeSamples(factory, batch, batch.samples.size(),
    516                     outSeq, outEvent);
    517             mBatches.removeAt(i);
    518             return result;
    519         }
    520 
    521         nsecs_t sampleTime = frameTime - RESAMPLE_LATENCY;
    522         ssize_t split = findSampleNoLaterThan(batch, sampleTime);
    523         if (split < 0) {
    524             continue;
    525         }
    526 
    527         result = consumeSamples(factory, batch, split + 1, outSeq, outEvent);
    528         const InputMessage* next;
    529         if (batch.samples.isEmpty()) {
    530             mBatches.removeAt(i);
    531             next = NULL;
    532         } else {
    533             next = &batch.samples.itemAt(0);
    534         }
    535         if (!result) {
    536             resampleTouchState(sampleTime, static_cast<MotionEvent*>(*outEvent), next);
    537         }
    538         return result;
    539     }
    540 
    541     return WOULD_BLOCK;
    542 }
    543 
    544 status_t InputConsumer::consumeSamples(InputEventFactoryInterface* factory,
    545         Batch& batch, size_t count, uint32_t* outSeq, InputEvent** outEvent) {
    546     MotionEvent* motionEvent = factory->createMotionEvent();
    547     if (! motionEvent) return NO_MEMORY;
    548 
    549     uint32_t chain = 0;
    550     for (size_t i = 0; i < count; i++) {
    551         InputMessage& msg = batch.samples.editItemAt(i);
    552         updateTouchState(&msg);
    553         if (i) {
    554             SeqChain seqChain;
    555             seqChain.seq = msg.body.motion.seq;
    556             seqChain.chain = chain;
    557             mSeqChains.push(seqChain);
    558             addSample(motionEvent, &msg);
    559         } else {
    560             initializeMotionEvent(motionEvent, &msg);
    561         }
    562         chain = msg.body.motion.seq;
    563     }
    564     batch.samples.removeItemsAt(0, count);
    565 
    566     *outSeq = chain;
    567     *outEvent = motionEvent;
    568     return OK;
    569 }
    570 
    571 void InputConsumer::updateTouchState(InputMessage* msg) {
    572     if (!mResampleTouch ||
    573             !(msg->body.motion.source & AINPUT_SOURCE_CLASS_POINTER)) {
    574         return;
    575     }
    576 
    577     int32_t deviceId = msg->body.motion.deviceId;
    578     int32_t source = msg->body.motion.source;
    579     nsecs_t eventTime = msg->body.motion.eventTime;
    580 
    581     // Update the touch state history to incorporate the new input message.
    582     // If the message is in the past relative to the most recently produced resampled
    583     // touch, then use the resampled time and coordinates instead.
    584     switch (msg->body.motion.action & AMOTION_EVENT_ACTION_MASK) {
    585     case AMOTION_EVENT_ACTION_DOWN: {
    586         ssize_t index = findTouchState(deviceId, source);
    587         if (index < 0) {
    588             mTouchStates.push();
    589             index = mTouchStates.size() - 1;
    590         }
    591         TouchState& touchState = mTouchStates.editItemAt(index);
    592         touchState.initialize(deviceId, source);
    593         touchState.addHistory(msg);
    594         break;
    595     }
    596 
    597     case AMOTION_EVENT_ACTION_MOVE: {
    598         ssize_t index = findTouchState(deviceId, source);
    599         if (index >= 0) {
    600             TouchState& touchState = mTouchStates.editItemAt(index);
    601             touchState.addHistory(msg);
    602             if (eventTime < touchState.lastResample.eventTime) {
    603                 rewriteMessage(touchState, msg);
    604             } else {
    605                 touchState.lastResample.idBits.clear();
    606             }
    607         }
    608         break;
    609     }
    610 
    611     case AMOTION_EVENT_ACTION_POINTER_DOWN: {
    612         ssize_t index = findTouchState(deviceId, source);
    613         if (index >= 0) {
    614             TouchState& touchState = mTouchStates.editItemAt(index);
    615             touchState.lastResample.idBits.clearBit(msg->body.motion.getActionId());
    616             rewriteMessage(touchState, msg);
    617         }
    618         break;
    619     }
    620 
    621     case AMOTION_EVENT_ACTION_POINTER_UP: {
    622         ssize_t index = findTouchState(deviceId, source);
    623         if (index >= 0) {
    624             TouchState& touchState = mTouchStates.editItemAt(index);
    625             rewriteMessage(touchState, msg);
    626             touchState.lastResample.idBits.clearBit(msg->body.motion.getActionId());
    627         }
    628         break;
    629     }
    630 
    631     case AMOTION_EVENT_ACTION_SCROLL: {
    632         ssize_t index = findTouchState(deviceId, source);
    633         if (index >= 0) {
    634             const TouchState& touchState = mTouchStates.itemAt(index);
    635             rewriteMessage(touchState, msg);
    636         }
    637         break;
    638     }
    639 
    640     case AMOTION_EVENT_ACTION_UP:
    641     case AMOTION_EVENT_ACTION_CANCEL: {
    642         ssize_t index = findTouchState(deviceId, source);
    643         if (index >= 0) {
    644             const TouchState& touchState = mTouchStates.itemAt(index);
    645             rewriteMessage(touchState, msg);
    646             mTouchStates.removeAt(index);
    647         }
    648         break;
    649     }
    650     }
    651 }
    652 
    653 void InputConsumer::rewriteMessage(const TouchState& state, InputMessage* msg) {
    654     for (size_t i = 0; i < msg->body.motion.pointerCount; i++) {
    655         uint32_t id = msg->body.motion.pointers[i].properties.id;
    656         if (state.lastResample.idBits.hasBit(id)) {
    657             PointerCoords& msgCoords = msg->body.motion.pointers[i].coords;
    658             const PointerCoords& resampleCoords = state.lastResample.getPointerById(id);
    659 #if DEBUG_RESAMPLING
    660             ALOGD("[%d] - rewrite (%0.3f, %0.3f), old (%0.3f, %0.3f)", id,
    661                     resampleCoords.getAxisValue(AMOTION_EVENT_AXIS_X),
    662                     resampleCoords.getAxisValue(AMOTION_EVENT_AXIS_Y),
    663                     msgCoords.getAxisValue(AMOTION_EVENT_AXIS_X),
    664                     msgCoords.getAxisValue(AMOTION_EVENT_AXIS_Y));
    665 #endif
    666             msgCoords.setAxisValue(AMOTION_EVENT_AXIS_X, resampleCoords.getX());
    667             msgCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, resampleCoords.getY());
    668         }
    669     }
    670 }
    671 
    672 void InputConsumer::resampleTouchState(nsecs_t sampleTime, MotionEvent* event,
    673     const InputMessage* next) {
    674     if (!mResampleTouch
    675             || !(event->getSource() & AINPUT_SOURCE_CLASS_POINTER)
    676             || event->getAction() != AMOTION_EVENT_ACTION_MOVE) {
    677         return;
    678     }
    679 
    680     ssize_t index = findTouchState(event->getDeviceId(), event->getSource());
    681     if (index < 0) {
    682 #if DEBUG_RESAMPLING
    683         ALOGD("Not resampled, no touch state for device.");
    684 #endif
    685         return;
    686     }
    687 
    688     TouchState& touchState = mTouchStates.editItemAt(index);
    689     if (touchState.historySize < 1) {
    690 #if DEBUG_RESAMPLING
    691         ALOGD("Not resampled, no history for device.");
    692 #endif
    693         return;
    694     }
    695 
    696     // Ensure that the current sample has all of the pointers that need to be reported.
    697     const History* current = touchState.getHistory(0);
    698     size_t pointerCount = event->getPointerCount();
    699     for (size_t i = 0; i < pointerCount; i++) {
    700         uint32_t id = event->getPointerId(i);
    701         if (!current->idBits.hasBit(id)) {
    702 #if DEBUG_RESAMPLING
    703             ALOGD("Not resampled, missing id %d", id);
    704 #endif
    705             return;
    706         }
    707     }
    708 
    709     // Find the data to use for resampling.
    710     const History* other;
    711     History future;
    712     float alpha;
    713     if (next) {
    714         // Interpolate between current sample and future sample.
    715         // So current->eventTime <= sampleTime <= future.eventTime.
    716         future.initializeFrom(next);
    717         other = &future;
    718         nsecs_t delta = future.eventTime - current->eventTime;
    719         if (delta < RESAMPLE_MIN_DELTA) {
    720 #if DEBUG_RESAMPLING
    721             ALOGD("Not resampled, delta time is %lld ns.", delta);
    722 #endif
    723             return;
    724         }
    725         alpha = float(sampleTime - current->eventTime) / delta;
    726     } else if (touchState.historySize >= 2) {
    727         // Extrapolate future sample using current sample and past sample.
    728         // So other->eventTime <= current->eventTime <= sampleTime.
    729         other = touchState.getHistory(1);
    730         nsecs_t delta = current->eventTime - other->eventTime;
    731         if (delta < RESAMPLE_MIN_DELTA) {
    732 #if DEBUG_RESAMPLING
    733             ALOGD("Not resampled, delta time is %lld ns.", delta);
    734 #endif
    735             return;
    736         }
    737         nsecs_t maxPredict = current->eventTime + min(delta / 2, RESAMPLE_MAX_PREDICTION);
    738         if (sampleTime > maxPredict) {
    739 #if DEBUG_RESAMPLING
    740             ALOGD("Sample time is too far in the future, adjusting prediction "
    741                     "from %lld to %lld ns.",
    742                     sampleTime - current->eventTime, maxPredict - current->eventTime);
    743 #endif
    744             sampleTime = maxPredict;
    745         }
    746         alpha = float(current->eventTime - sampleTime) / delta;
    747     } else {
    748 #if DEBUG_RESAMPLING
    749         ALOGD("Not resampled, insufficient data.");
    750 #endif
    751         return;
    752     }
    753 
    754     // Resample touch coordinates.
    755     touchState.lastResample.eventTime = sampleTime;
    756     touchState.lastResample.idBits.clear();
    757     for (size_t i = 0; i < pointerCount; i++) {
    758         uint32_t id = event->getPointerId(i);
    759         touchState.lastResample.idToIndex[id] = i;
    760         touchState.lastResample.idBits.markBit(id);
    761         PointerCoords& resampledCoords = touchState.lastResample.pointers[i];
    762         const PointerCoords& currentCoords = current->getPointerById(id);
    763         if (other->idBits.hasBit(id)
    764                 && shouldResampleTool(event->getToolType(i))) {
    765             const PointerCoords& otherCoords = other->getPointerById(id);
    766             resampledCoords.copyFrom(currentCoords);
    767             resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_X,
    768                     lerp(currentCoords.getX(), otherCoords.getX(), alpha));
    769             resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_Y,
    770                     lerp(currentCoords.getY(), otherCoords.getY(), alpha));
    771 #if DEBUG_RESAMPLING
    772             ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f), "
    773                     "other (%0.3f, %0.3f), alpha %0.3f",
    774                     id, resampledCoords.getX(), resampledCoords.getY(),
    775                     currentCoords.getX(), currentCoords.getY(),
    776                     otherCoords.getX(), otherCoords.getY(),
    777                     alpha);
    778 #endif
    779         } else {
    780             resampledCoords.copyFrom(currentCoords);
    781 #if DEBUG_RESAMPLING
    782             ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f)",
    783                     id, resampledCoords.getX(), resampledCoords.getY(),
    784                     currentCoords.getX(), currentCoords.getY());
    785 #endif
    786         }
    787     }
    788 
    789     event->addSample(sampleTime, touchState.lastResample.pointers);
    790 }
    791 
    792 bool InputConsumer::shouldResampleTool(int32_t toolType) {
    793     return toolType == AMOTION_EVENT_TOOL_TYPE_FINGER
    794             || toolType == AMOTION_EVENT_TOOL_TYPE_UNKNOWN;
    795 }
    796 
    797 status_t InputConsumer::sendFinishedSignal(uint32_t seq, bool handled) {
    798 #if DEBUG_TRANSPORT_ACTIONS
    799     ALOGD("channel '%s' consumer ~ sendFinishedSignal: seq=%u, handled=%s",
    800             mChannel->getName().string(), seq, handled ? "true" : "false");
    801 #endif
    802 
    803     if (!seq) {
    804         ALOGE("Attempted to send a finished signal with sequence number 0.");
    805         return BAD_VALUE;
    806     }
    807 
    808     // Send finished signals for the batch sequence chain first.
    809     size_t seqChainCount = mSeqChains.size();
    810     if (seqChainCount) {
    811         uint32_t currentSeq = seq;
    812         uint32_t chainSeqs[seqChainCount];
    813         size_t chainIndex = 0;
    814         for (size_t i = seqChainCount; i-- > 0; ) {
    815              const SeqChain& seqChain = mSeqChains.itemAt(i);
    816              if (seqChain.seq == currentSeq) {
    817                  currentSeq = seqChain.chain;
    818                  chainSeqs[chainIndex++] = currentSeq;
    819                  mSeqChains.removeAt(i);
    820              }
    821         }
    822         status_t status = OK;
    823         while (!status && chainIndex-- > 0) {
    824             status = sendUnchainedFinishedSignal(chainSeqs[chainIndex], handled);
    825         }
    826         if (status) {
    827             // An error occurred so at least one signal was not sent, reconstruct the chain.
    828             do {
    829                 SeqChain seqChain;
    830                 seqChain.seq = chainIndex != 0 ? chainSeqs[chainIndex - 1] : seq;
    831                 seqChain.chain = chainSeqs[chainIndex];
    832                 mSeqChains.push(seqChain);
    833             } while (chainIndex-- > 0);
    834             return status;
    835         }
    836     }
    837 
    838     // Send finished signal for the last message in the batch.
    839     return sendUnchainedFinishedSignal(seq, handled);
    840 }
    841 
    842 status_t InputConsumer::sendUnchainedFinishedSignal(uint32_t seq, bool handled) {
    843     InputMessage msg;
    844     msg.header.type = InputMessage::TYPE_FINISHED;
    845     msg.body.finished.seq = seq;
    846     msg.body.finished.handled = handled;
    847     return mChannel->sendMessage(&msg);
    848 }
    849 
    850 bool InputConsumer::hasDeferredEvent() const {
    851     return mMsgDeferred;
    852 }
    853 
    854 bool InputConsumer::hasPendingBatch() const {
    855     return !mBatches.isEmpty();
    856 }
    857 
    858 ssize_t InputConsumer::findBatch(int32_t deviceId, int32_t source) const {
    859     for (size_t i = 0; i < mBatches.size(); i++) {
    860         const Batch& batch = mBatches.itemAt(i);
    861         const InputMessage& head = batch.samples.itemAt(0);
    862         if (head.body.motion.deviceId == deviceId && head.body.motion.source == source) {
    863             return i;
    864         }
    865     }
    866     return -1;
    867 }
    868 
    869 ssize_t InputConsumer::findTouchState(int32_t deviceId, int32_t source) const {
    870     for (size_t i = 0; i < mTouchStates.size(); i++) {
    871         const TouchState& touchState = mTouchStates.itemAt(i);
    872         if (touchState.deviceId == deviceId && touchState.source == source) {
    873             return i;
    874         }
    875     }
    876     return -1;
    877 }
    878 
    879 void InputConsumer::initializeKeyEvent(KeyEvent* event, const InputMessage* msg) {
    880     event->initialize(
    881             msg->body.key.deviceId,
    882             msg->body.key.source,
    883             msg->body.key.action,
    884             msg->body.key.flags,
    885             msg->body.key.keyCode,
    886             msg->body.key.scanCode,
    887             msg->body.key.metaState,
    888             msg->body.key.repeatCount,
    889             msg->body.key.downTime,
    890             msg->body.key.eventTime);
    891 }
    892 
    893 void InputConsumer::initializeMotionEvent(MotionEvent* event, const InputMessage* msg) {
    894     size_t pointerCount = msg->body.motion.pointerCount;
    895     PointerProperties pointerProperties[pointerCount];
    896     PointerCoords pointerCoords[pointerCount];
    897     for (size_t i = 0; i < pointerCount; i++) {
    898         pointerProperties[i].copyFrom(msg->body.motion.pointers[i].properties);
    899         pointerCoords[i].copyFrom(msg->body.motion.pointers[i].coords);
    900     }
    901 
    902     event->initialize(
    903             msg->body.motion.deviceId,
    904             msg->body.motion.source,
    905             msg->body.motion.action,
    906             msg->body.motion.flags,
    907             msg->body.motion.edgeFlags,
    908             msg->body.motion.metaState,
    909             msg->body.motion.buttonState,
    910             msg->body.motion.xOffset,
    911             msg->body.motion.yOffset,
    912             msg->body.motion.xPrecision,
    913             msg->body.motion.yPrecision,
    914             msg->body.motion.downTime,
    915             msg->body.motion.eventTime,
    916             pointerCount,
    917             pointerProperties,
    918             pointerCoords);
    919 }
    920 
    921 void InputConsumer::addSample(MotionEvent* event, const InputMessage* msg) {
    922     size_t pointerCount = msg->body.motion.pointerCount;
    923     PointerCoords pointerCoords[pointerCount];
    924     for (size_t i = 0; i < pointerCount; i++) {
    925         pointerCoords[i].copyFrom(msg->body.motion.pointers[i].coords);
    926     }
    927 
    928     event->setMetaState(event->getMetaState() | msg->body.motion.metaState);
    929     event->addSample(msg->body.motion.eventTime, pointerCoords);
    930 }
    931 
    932 bool InputConsumer::canAddSample(const Batch& batch, const InputMessage *msg) {
    933     const InputMessage& head = batch.samples.itemAt(0);
    934     size_t pointerCount = msg->body.motion.pointerCount;
    935     if (head.body.motion.pointerCount != pointerCount
    936             || head.body.motion.action != msg->body.motion.action) {
    937         return false;
    938     }
    939     for (size_t i = 0; i < pointerCount; i++) {
    940         if (head.body.motion.pointers[i].properties
    941                 != msg->body.motion.pointers[i].properties) {
    942             return false;
    943         }
    944     }
    945     return true;
    946 }
    947 
    948 ssize_t InputConsumer::findSampleNoLaterThan(const Batch& batch, nsecs_t time) {
    949     size_t numSamples = batch.samples.size();
    950     size_t index = 0;
    951     while (index < numSamples
    952             && batch.samples.itemAt(index).body.motion.eventTime <= time) {
    953         index += 1;
    954     }
    955     return ssize_t(index) - 1;
    956 }
    957 
    958 } // namespace android
    959