diff options
| -rw-r--r-- | src/plugins/sensors/blackberry/bbsensorbackend.cpp | 23 | ||||
| -rw-r--r-- | src/sensors/qsensor.cpp | 11 |
2 files changed, 34 insertions, 0 deletions
diff --git a/src/plugins/sensors/blackberry/bbsensorbackend.cpp b/src/plugins/sensors/blackberry/bbsensorbackend.cpp index 7a8a2933..c13bc585 100644 --- a/src/plugins/sensors/blackberry/bbsensorbackend.cpp +++ b/src/plugins/sensors/blackberry/bbsensorbackend.cpp @@ -45,6 +45,7 @@ #include <fcntl.h> static const int microSecondsPerSecond = 1000 * 1000; +static const int defaultBufferSize = 10; static int microSecondsToHertz(uint microSeconds) { @@ -62,6 +63,10 @@ BbSensorBackendBase::BbSensorBackendBase(const QString &devicePath, sensor_type_ { QCoreApplication::instance()->installEventFilter(this); connect(sensor, SIGNAL(alwaysOnChanged()), this, SLOT(applyAlwaysOnProperty())); + + // Set some sensible default values + sensor->setProperty("efficientBufferSize", defaultBufferSize); + sensor->setProperty("maxBufferSize", defaultBufferSize); } QFile &BbSensorBackendBase::deviceFile() @@ -169,6 +174,24 @@ void BbSensorBackendBase::start() return; } + // Activate event queuing if needed + bool ok = false; + const int requestedBufferSize = sensor()->property("bufferSize").toInt(&ok); + if (ok && requestedBufferSize > 1) { + sensor_devctl_queue_u queueControl; + queueControl.tx.enable = 1; + const int result = devctl(m_deviceFile.handle(), DCMD_SENSOR_QUEUE, &queueControl, sizeof(queueControl), NULL); + if (result != EOK) { + perror(QString::fromLatin1("Enabling sensor queuing for %1 failed") + .arg(m_deviceFile.fileName()).toLocal8Bit()); + } + + const int actualBufferSize = queueControl.rx.size; + sensor()->setProperty("bufferSize", actualBufferSize); + sensor()->setProperty("efficientBufferSize", actualBufferSize); + sensor()->setProperty("maxBufferSize", actualBufferSize); + } + applyAlwaysOnProperty(); m_socketNotifier.reset(new QSocketNotifier(m_deviceFile.handle(), QSocketNotifier::Read)); diff --git a/src/sensors/qsensor.cpp b/src/sensors/qsensor.cpp index 2949e771..be0c7862 100644 --- a/src/sensors/qsensor.cpp +++ b/src/sensors/qsensor.cpp @@ -776,6 +776,17 @@ int QSensor::error() const When the sensor is started with buffering option, values are collected from that moment onwards. There is no pre-existing buffer that can be utilized. + Some backends like Blackberry only support enabling or disabling the buffer and do not give + control over the size. In this case, the maxBufferSize and efficientBufferSize properties + might not be set at all, even though buffering is supported. Setting the bufferSize property + to any value greater than 1 will enable buffering. After the sensor has been started, + the bufferSize property will be set to the actual value by the backend. + + On Blackberry, buffering will not wait until the buffer is full to deliver new + readings. Instead, the buffer will be used if the backend does not manage to retrieve the readings + in time, for example when the event loop is blocked for too long. Without a buffer, these readings + would simply be dropped. + The buffer size can only be changed while the sensor is not active. \sa QSensor::maxBufferSize, QSensor::efficientBufferSize |