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
diff --git a/include/gui/BitTube.h b/include/gui/BitTube.h
index 3022d05..d32df84 100644
--- a/include/gui/BitTube.h
+++ b/include/gui/BitTube.h
@@ -33,30 +33,49 @@
{
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;
diff --git a/include/gui/SensorEventQueue.h b/include/gui/SensorEventQueue.h
index 8d8493b..a3a9daa 100644
--- a/include/gui/SensorEventQueue.h
+++ b/include/gui/SensorEventQueue.h
@@ -49,6 +49,9 @@
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 @@
sp<BitTube> mSensorChannel;
mutable Mutex mLock;
mutable sp<Looper> mLooper;
+ ASensorEvent* mRecBuffer;
+ size_t mAvailable;
+ size_t mConsumed;
};
// ----------------------------------------------------------------------------
diff --git a/libs/gui/BitTube.cpp b/libs/gui/BitTube.cpp
index cf44bb9..85a7de7 100644
--- a/libs/gui/BitTube.cpp
+++ b/libs/gui/BitTube.cpp
@@ -32,39 +32,26 @@
// 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 @@
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 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 @@
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;
}
// ----------------------------------------------------------------------------
diff --git a/libs/gui/SensorEventQueue.cpp b/libs/gui/SensorEventQueue.cpp
index 08b8ac8..ab50c1d 100644
--- a/libs/gui/SensorEventQueue.cpp
+++ b/libs/gui/SensorEventQueue.cpp
@@ -35,12 +35,12 @@
// ----------------------------------------------------------------------------
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 @@
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
diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index 7bb6e86..cb99531 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -292,8 +292,12 @@
{
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());
