libs/ui/InputTransport.cpp

//
// Copyright 2010 The Android Open Source Project
//
// Provides a shared memory transport for input events.
//
#define LOG_TAG "InputTransport"

//#define LOG_NDEBUG 0

// Log debug messages about channel messages (send message, receive message)
#define DEBUG_CHANNEL_MESSAGES 0

// Log debug messages whenever InputChannel objects are created/destroyed
#define DEBUG_CHANNEL_LIFECYCLE 0

#define DEBUG_TRANSPORT_ACTIONS 0
// Log debug messages about transport actions


#include <cutils/log.h>
#include <errno.h>
#include <fcntl.h>
#include <ui/InputTransport.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>


namespace android {

// Socket buffer size.  The default is typically about 128KB, which is much larger than
// we really need.  So we make it smaller.  It just needs to be big enough to hold
// a few dozen large multi-finger motion events in the case where an application gets
// behind processing touches.
static const size_t SOCKET_BUFFER_SIZE = 32 * 1024;


// --- InputMessage ---

bool InputMessage::isValid(size_t actualSize) const {
    if (size() == actualSize) {
        switch (header.type) {
        case TYPE_KEY:
            return true;
        case TYPE_MOTION:
            return body.motion.pointerCount > 0
                    && body.motion.pointerCount <= MAX_POINTERS;
        case TYPE_FINISHED:
            return true;
        }
    }
    return false;
}

size_t InputMessage::size() const {
    switch (header.type) {
    case TYPE_KEY:
        return sizeof(Header) + body.key.size();
    case TYPE_MOTION:
        return sizeof(Header) + body.motion.size();
    case TYPE_FINISHED:
        return sizeof(Header) + body.finished.size();
    }
    return sizeof(Header);
}


// --- InputChannel ---

InputChannel::InputChannel(const String8& name, int fd) :
        mName(name), mFd(fd) {
#if DEBUG_CHANNEL_LIFECYCLE
    ALOGD("Input channel constructed: name='%s', fd=%d",
            mName.string(), fd);
#endif

    int result = fcntl(mFd, F_SETFL, O_NONBLOCK);
    LOG_ALWAYS_FATAL_IF(result != 0, "channel '%s' ~ Could not make socket "
            "non-blocking.  errno=%d", mName.string(), errno);
}

InputChannel::~InputChannel() {
#if DEBUG_CHANNEL_LIFECYCLE
    ALOGD("Input channel destroyed: name='%s', fd=%d",
            mName.string(), mFd);
#endif

    ::close(mFd);
}

status_t InputChannel::openInputChannelPair(const String8& name,
        sp<InputChannel>& outServerChannel, sp<InputChannel>& outClientChannel) {
    int sockets[2];
    if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets)) {
        status_t result = -errno;
        ALOGE("channel '%s' ~ Could not create socket pair.  errno=%d",
                name.string(), errno);
        outServerChannel.clear();
        outClientChannel.clear();
        return result;
    }

    int bufferSize = SOCKET_BUFFER_SIZE;
    setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
    setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
    setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
    setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));

    String8 serverChannelName = name;
    serverChannelName.append(" (server)");
    outServerChannel = new InputChannel(serverChannelName, sockets[0]);

    String8 clientChannelName = name;
    clientChannelName.append(" (client)");
    outClientChannel = new InputChannel(clientChannelName, sockets[1]);
    return OK;
}

status_t InputChannel::sendMessage(const InputMessage* msg) {
    size_t msgLength = msg->size();
    ssize_t nWrite;
    do {
        nWrite = ::send(mFd, msg, msgLength, MSG_DONTWAIT | MSG_NOSIGNAL);
    } while (nWrite == -1 && errno == EINTR);

    if (nWrite < 0) {
        int error = errno;
#if DEBUG_CHANNEL_MESSAGES
        ALOGD("channel '%s' ~ error sending message of type %d, errno=%d", mName.string(),
                msg->header.type, error);
#endif
        if (error == EAGAIN || error == EWOULDBLOCK) {
            return WOULD_BLOCK;
        }
        if (error == EPIPE || error == ENOTCONN) {
            return DEAD_OBJECT;
        }
        return -error;
    }

    if (size_t(nWrite) != msgLength) {
#if DEBUG_CHANNEL_MESSAGES
        ALOGD("channel '%s' ~ error sending message type %d, send was incomplete",
                mName.string(), msg->header.type);
#endif
        return DEAD_OBJECT;
    }

#if DEBUG_CHANNEL_MESSAGES
    ALOGD("channel '%s' ~ sent message of type %d", mName.string(), msg->header.type);
#endif
    return OK;
}

status_t InputChannel::receiveMessage(InputMessage* msg) {
    ssize_t nRead;
    do {
        nRead = ::recv(mFd, msg, sizeof(InputMessage), MSG_DONTWAIT);
    } while (nRead == -1 && errno == EINTR);

    if (nRead < 0) {
        int error = errno;
#if DEBUG_CHANNEL_MESSAGES
        ALOGD("channel '%s' ~ receive message failed, errno=%d", mName.string(), errno);
#endif
        if (error == EAGAIN || error == EWOULDBLOCK) {
            return WOULD_BLOCK;
        }
        if (error == EPIPE || error == ENOTCONN) {
            return DEAD_OBJECT;
        }
        return -error;
    }

    if (nRead == 0) { // check for EOF
#if DEBUG_CHANNEL_MESSAGES
        ALOGD("channel '%s' ~ receive message failed because peer was closed", mName.string());
#endif
        return DEAD_OBJECT;
    }

    if (!msg->isValid(nRead)) {
#if DEBUG_CHANNEL_MESSAGES
        ALOGD("channel '%s' ~ received invalid message", mName.string());
#endif
        return BAD_VALUE;
    }

#if DEBUG_CHANNEL_MESSAGES
    ALOGD("channel '%s' ~ received message of type %d", mName.string(), msg->header.type);
#endif
    return OK;
}


// --- InputPublisher ---

InputPublisher::InputPublisher(const sp<InputChannel>& channel) :
        mChannel(channel) {
}

InputPublisher::~InputPublisher() {
}

status_t InputPublisher::publishKeyEvent(
        int32_t deviceId,
        int32_t source,
        int32_t action,
        int32_t flags,
        int32_t keyCode,
        int32_t scanCode,
        int32_t metaState,
        int32_t repeatCount,
        nsecs_t downTime,
        nsecs_t eventTime) {
#if DEBUG_TRANSPORT_ACTIONS
    ALOGD("channel '%s' publisher ~ publishKeyEvent: deviceId=%d, source=0x%x, "
            "action=0x%x, flags=0x%x, keyCode=%d, scanCode=%d, metaState=0x%x, repeatCount=%d,"
            "downTime=%lld, eventTime=%lld",
            mChannel->getName().string(),
            deviceId, source, action, flags, keyCode, scanCode, metaState, repeatCount,
            downTime, eventTime);
#endif

    InputMessage msg;
    msg.header.type = InputMessage::TYPE_KEY;
    msg.body.key.deviceId = deviceId;
    msg.body.key.source = source;
    msg.body.key.action = action;
    msg.body.key.flags = flags;
    msg.body.key.keyCode = keyCode;
    msg.body.key.scanCode = scanCode;
    msg.body.key.metaState = metaState;
    msg.body.key.repeatCount = repeatCount;
    msg.body.key.downTime = downTime;
    msg.body.key.eventTime = eventTime;
    return mChannel->sendMessage(&msg);
}

status_t InputPublisher::publishMotionEvent(
        int32_t deviceId,
        int32_t source,
        int32_t action,
        int32_t flags,
        int32_t edgeFlags,
        int32_t metaState,
        int32_t buttonState,
        float xOffset,
        float yOffset,
        float xPrecision,
        float yPrecision,
        nsecs_t downTime,
        nsecs_t eventTime,
        size_t pointerCount,
        const PointerProperties* pointerProperties,
        const PointerCoords* pointerCoords) {
#if DEBUG_TRANSPORT_ACTIONS
    ALOGD("channel '%s' publisher ~ publishMotionEvent: deviceId=%d, source=0x%x, "
            "action=0x%x, flags=0x%x, edgeFlags=0x%x, metaState=0x%x, buttonState=0x%x, "
            "xOffset=%f, yOffset=%f, "
            "xPrecision=%f, yPrecision=%f, downTime=%lld, eventTime=%lld, "
            "pointerCount=%d",
            mChannel->getName().string(),
            deviceId, source, action, flags, edgeFlags, metaState, buttonState,
            xOffset, yOffset, xPrecision, yPrecision, downTime, eventTime, pointerCount);
#endif

    if (pointerCount > MAX_POINTERS || pointerCount < 1) {
        ALOGE("channel '%s' publisher ~ Invalid number of pointers provided: %d.",
                mChannel->getName().string(), pointerCount);
        return BAD_VALUE;
    }

    InputMessage msg;
    msg.header.type = InputMessage::TYPE_MOTION;
    msg.body.motion.deviceId = deviceId;
    msg.body.motion.source = source;
    msg.body.motion.action = action;
    msg.body.motion.flags = flags;
    msg.body.motion.edgeFlags = edgeFlags;
    msg.body.motion.metaState = metaState;
    msg.body.motion.buttonState = buttonState;
    msg.body.motion.xOffset = xOffset;
    msg.body.motion.yOffset = yOffset;
    msg.body.motion.xPrecision = xPrecision;
    msg.body.motion.yPrecision = yPrecision;
    msg.body.motion.downTime = downTime;
    msg.body.motion.eventTime = eventTime;
    msg.body.motion.pointerCount = pointerCount;
    for (size_t i = 0; i < pointerCount; i++) {
        msg.body.motion.pointers[i].properties.copyFrom(pointerProperties[i]);
        msg.body.motion.pointers[i].coords.copyFrom(pointerCoords[i]);
    }
    return mChannel->sendMessage(&msg);
}

status_t InputPublisher::receiveFinishedSignal(bool* outHandled) {
#if DEBUG_TRANSPORT_ACTIONS
    ALOGD("channel '%s' publisher ~ receiveFinishedSignal",
            mChannel->getName().string());
#endif

    InputMessage msg;
    status_t result = mChannel->receiveMessage(&msg);
    if (result) {
        *outHandled = false;
        return result;
    }
    if (msg.header.type != InputMessage::TYPE_FINISHED) {
        ALOGE("channel '%s' publisher ~ Received unexpected message of type %d from consumer",
                mChannel->getName().string(), msg.header.type);
        return UNKNOWN_ERROR;
    }
    *outHandled = msg.body.finished.handled;
    return OK;
}

// --- InputConsumer ---

InputConsumer::InputConsumer(const sp<InputChannel>& channel) :
        mChannel(channel) {
}

InputConsumer::~InputConsumer() {
}

status_t InputConsumer::consume(InputEventFactoryInterface* factory, InputEvent** outEvent) {
#if DEBUG_TRANSPORT_ACTIONS
    ALOGD("channel '%s' consumer ~ consume",
            mChannel->getName().string());
#endif

    *outEvent = NULL;

    InputMessage msg;
    status_t result = mChannel->receiveMessage(&msg);
    if (result) {
        return result;
    }

    switch (msg.header.type) {
    case InputMessage::TYPE_KEY: {
        KeyEvent* keyEvent = factory->createKeyEvent();
        if (!keyEvent) return NO_MEMORY;

        keyEvent->initialize(
                msg.body.key.deviceId,
                msg.body.key.source,
                msg.body.key.action,
                msg.body.key.flags,
                msg.body.key.keyCode,
                msg.body.key.scanCode,
                msg.body.key.metaState,
                msg.body.key.repeatCount,
                msg.body.key.downTime,
                msg.body.key.eventTime);
        *outEvent = keyEvent;
        break;
    }

    case AINPUT_EVENT_TYPE_MOTION: {
        MotionEvent* motionEvent = factory->createMotionEvent();
        if (! motionEvent) return NO_MEMORY;

        size_t pointerCount = msg.body.motion.pointerCount;
        PointerProperties pointerProperties[pointerCount];
        PointerCoords pointerCoords[pointerCount];
        for (size_t i = 0; i < pointerCount; i++) {
            pointerProperties[i].copyFrom(msg.body.motion.pointers[i].properties);
            pointerCoords[i].copyFrom(msg.body.motion.pointers[i].coords);
        }

        motionEvent->initialize(
                msg.body.motion.deviceId,
                msg.body.motion.source,
                msg.body.motion.action,
                msg.body.motion.flags,
                msg.body.motion.edgeFlags,
                msg.body.motion.metaState,
                msg.body.motion.buttonState,
                msg.body.motion.xOffset,
                msg.body.motion.yOffset,
                msg.body.motion.xPrecision,
                msg.body.motion.yPrecision,
                msg.body.motion.downTime,
                msg.body.motion.eventTime,
                pointerCount,
                pointerProperties,
                pointerCoords);
        *outEvent = motionEvent;
        break;
    }

    default:
        ALOGE("channel '%s' consumer ~ Received unexpected message of type %d",
                mChannel->getName().string(), msg.header.type);
        return UNKNOWN_ERROR;
    }

    return OK;
}

status_t InputConsumer::sendFinishedSignal(bool handled) {
#if DEBUG_TRANSPORT_ACTIONS
    ALOGD("channel '%s' consumer ~ sendFinishedSignal: handled=%d",
            mChannel->getName().string(), handled);
#endif

    InputMessage msg;
    msg.header.type = InputMessage::TYPE_FINISHED;
    msg.body.finished.handled = handled;
    return mChannel->sendMessage(&msg);
}

} // namespace android