fix a few problems with BitTube

BitTube used to send objects one at a time and didn't
handle errors properly.

We now send all the objects in one call, which means they
have to be read as a single batch as well. This changes the
BitTube API.

Update SensorService to the new API.

Also added an API to set the size of the send buffer.

Bug: 10641596
Change-Id: I77c70d35e351fdba0416fae4b7ca3b1d56272251
This commit is contained in:
Mathias Agopian 2013-09-09 23:36:25 -07:00
parent 63108c34ec
commit 90ed3e8d78
5 changed files with 105 additions and 66 deletions

View File

@ -33,30 +33,49 @@ class BitTube : public RefBase
{
public:
BitTube();
BitTube(const Parcel& data);
// creates a BitTube with a default (4KB) send buffer
BitTube();
// creates a BitTube with a a specified send and receive buffer size
explicit BitTube(size_t bufsize);
explicit BitTube(const Parcel& data);
virtual ~BitTube();
// check state after construction
status_t initCheck() const;
// get receive file-descriptor
int getFd() const;
ssize_t write(void const* vaddr, size_t size);
ssize_t read(void* vaddr, size_t size);
status_t writeToParcel(Parcel* reply) const;
// send objects (sized blobs). All objects are guaranteed to be written or the call fails.
template <typename T>
static ssize_t sendObjects(const sp<BitTube>& tube,
T const* events, size_t count) {
return sendObjects(tube, events, count, sizeof(T));
}
// receive objects (sized blobs). If the receiving buffer isn't large enough,
// excess messages are silently discarded.
template <typename T>
static ssize_t recvObjects(const sp<BitTube>& tube,
T* events, size_t count) {
return recvObjects(tube, events, count, sizeof(T));
}
// parcels this BitTube
status_t writeToParcel(Parcel* reply) const;
private:
void init(size_t rcvbuf, size_t sndbuf);
// send a message. The write is guaranteed to send the whole message or fail.
ssize_t write(void const* vaddr, size_t size);
// receive a message. the passed buffer must be at least as large as the
// write call used to send the message, excess data is silently discarded.
ssize_t read(void* vaddr, size_t size);
int mSendFd;
mutable int mReceiveFd;

View File

@ -49,6 +49,9 @@ class Looper;
class SensorEventQueue : public ASensorEventQueue, public RefBase
{
public:
enum { MAX_RECEIVE_BUFFER_EVENT_COUNT = 256 };
SensorEventQueue(const sp<ISensorEventConnection>& connection);
virtual ~SensorEventQueue();
virtual void onFirstRef();
@ -79,6 +82,9 @@ private:
sp<BitTube> mSensorChannel;
mutable Mutex mLock;
mutable sp<Looper> mLooper;
ASensorEvent* mRecBuffer;
size_t mAvailable;
size_t mConsumed;
};
// ----------------------------------------------------------------------------

View File

@ -32,39 +32,26 @@ namespace android {
// Socket buffer size. The default is typically about 128KB, which is much larger than
// we really need. So we make it smaller.
static const size_t SOCKET_BUFFER_SIZE = 4 * 1024;
static const size_t DEFAULT_SOCKET_BUFFER_SIZE = 4 * 1024;
BitTube::BitTube()
: mSendFd(-1), mReceiveFd(-1)
{
int sockets[2];
if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) {
int size = SOCKET_BUFFER_SIZE;
setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
fcntl(sockets[0], F_SETFL, O_NONBLOCK);
fcntl(sockets[1], F_SETFL, O_NONBLOCK);
mReceiveFd = sockets[0];
mSendFd = sockets[1];
} else {
mReceiveFd = -errno;
ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd));
}
init(DEFAULT_SOCKET_BUFFER_SIZE, DEFAULT_SOCKET_BUFFER_SIZE);
}
BitTube::BitTube(size_t bufsize)
: mSendFd(-1), mReceiveFd(-1)
{
init(bufsize, bufsize);
}
BitTube::BitTube(const Parcel& data)
: mSendFd(-1), mReceiveFd(-1)
{
mReceiveFd = dup(data.readFileDescriptor());
if (mReceiveFd >= 0) {
int size = SOCKET_BUFFER_SIZE;
setsockopt(mReceiveFd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
setsockopt(mReceiveFd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
fcntl(mReceiveFd, F_SETFL, O_NONBLOCK);
} else {
if (mReceiveFd < 0) {
mReceiveFd = -errno;
ALOGE("BitTube(Parcel): can't dup filedescriptor (%s)",
strerror(-mReceiveFd));
@ -80,6 +67,25 @@ BitTube::~BitTube()
close(mReceiveFd);
}
void BitTube::init(size_t rcvbuf, size_t sndbuf) {
int sockets[2];
if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) {
size_t size = DEFAULT_SOCKET_BUFFER_SIZE;
setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf));
setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(sndbuf));
// sine we don't use the "return channel", we keep it small...
setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
fcntl(sockets[0], F_SETFL, O_NONBLOCK);
fcntl(sockets[1], F_SETFL, O_NONBLOCK);
mReceiveFd = sockets[0];
mSendFd = sockets[1];
} else {
mReceiveFd = -errno;
ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd));
}
}
status_t BitTube::initCheck() const
{
if (mReceiveFd < 0) {
@ -98,10 +104,10 @@ ssize_t BitTube::write(void const* vaddr, size_t size)
ssize_t err, len;
do {
len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL);
// cannot return less than size, since we're using SOCK_SEQPACKET
err = len < 0 ? errno : 0;
} while (err == EINTR);
return err == 0 ? len : -err;
}
ssize_t BitTube::read(void* vaddr, size_t size)
@ -134,39 +140,31 @@ status_t BitTube::writeToParcel(Parcel* reply) const
ssize_t BitTube::sendObjects(const sp<BitTube>& tube,
void const* events, size_t count, size_t objSize)
{
ssize_t numObjects = 0;
for (size_t i=0 ; i<count ; i++) {
const char* vaddr = reinterpret_cast<const char*>(events) + objSize * i;
ssize_t size = tube->write(vaddr, objSize);
if (size < 0) {
// error occurred
return size;
} else if (size == 0) {
// no more space
break;
}
numObjects++;
}
return numObjects;
const char* vaddr = reinterpret_cast<const char*>(events);
ssize_t size = tube->write(vaddr, count*objSize);
// should never happen because of SOCK_SEQPACKET
LOG_ALWAYS_FATAL_IF((size >= 0) && (size % objSize),
"BitTube::sendObjects(count=%d, size=%d), res=%d (partial events were sent!)",
count, objSize, size);
//ALOGE_IF(size<0, "error %d sending %d events", size, count);
return size < 0 ? size : size / objSize;
}
ssize_t BitTube::recvObjects(const sp<BitTube>& tube,
void* events, size_t count, size_t objSize)
{
ssize_t numObjects = 0;
for (size_t i=0 ; i<count ; i++) {
char* vaddr = reinterpret_cast<char*>(events) + objSize * i;
ssize_t size = tube->read(vaddr, objSize);
if (size < 0) {
// error occurred
return size;
} else if (size == 0) {
// no more messages
break;
}
numObjects++;
}
return numObjects;
char* vaddr = reinterpret_cast<char*>(events);
ssize_t size = tube->read(vaddr, count*objSize);
// should never happen because of SOCK_SEQPACKET
LOG_ALWAYS_FATAL_IF((size >= 0) && (size % objSize),
"BitTube::recvObjects(count=%d, size=%d), res=%d (partial events were received!)",
count, objSize, size);
//ALOGE_IF(size<0, "error %d receiving %d events", size, count);
return size < 0 ? size : size / objSize;
}
// ----------------------------------------------------------------------------

View File

@ -35,12 +35,12 @@ namespace android {
// ----------------------------------------------------------------------------
SensorEventQueue::SensorEventQueue(const sp<ISensorEventConnection>& connection)
: mSensorEventConnection(connection)
{
: mSensorEventConnection(connection), mRecBuffer(NULL), mAvailable(0), mConsumed(0) {
mRecBuffer = new ASensorEvent[MAX_RECEIVE_BUFFER_EVENT_COUNT];
}
SensorEventQueue::~SensorEventQueue()
{
SensorEventQueue::~SensorEventQueue() {
delete [] mRecBuffer;
}
void SensorEventQueue::onFirstRef()
@ -59,9 +59,21 @@ ssize_t SensorEventQueue::write(const sp<BitTube>& tube,
return BitTube::sendObjects(tube, events, numEvents);
}
ssize_t SensorEventQueue::read(ASensorEvent* events, size_t numEvents)
{
return BitTube::recvObjects(mSensorChannel, events, numEvents);
ssize_t SensorEventQueue::read(ASensorEvent* events, size_t numEvents) {
if (mAvailable == 0) {
ssize_t err = BitTube::recvObjects(mSensorChannel,
mRecBuffer, MAX_RECEIVE_BUFFER_EVENT_COUNT);
if (err < 0) {
return err;
}
mAvailable = err;
mConsumed = 0;
}
size_t count = numEvents < mAvailable ? numEvents : mAvailable;
memcpy(events, mRecBuffer + mConsumed, count*sizeof(ASensorEvent));
mAvailable -= count;
mConsumed += count;
return count;
}
sp<Looper> SensorEventQueue::getLooper() const

View File

@ -292,8 +292,12 @@ bool SensorService::threadLoop()
{
ALOGD("nuSensorService thread starting...");
const size_t numEventMax = 16;
const size_t minBufferSize = numEventMax + numEventMax * mVirtualSensorList.size();
// each virtual sensor could generate an event per "real" event, that's why we need
// to size numEventMax much smaller than MAX_RECEIVE_BUFFER_EVENT_COUNT.
// in practice, this is too aggressive, but guaranteed to be enough.
const size_t minBufferSize = SensorEventQueue::MAX_RECEIVE_BUFFER_EVENT_COUNT;
const size_t numEventMax = minBufferSize / (1 + mVirtualSensorList.size());
sensors_event_t buffer[minBufferSize];
sensors_event_t scratch[minBufferSize];
SensorDevice& device(SensorDevice::getInstance());