SensorService flush fixes.
i) Fix a possible race condition when adding a pending flush connection
to mActiveSensors data structure.
ii) Invalidate flush_complete_events as soon as they are consumed by a
connection so that they are not used by other connections which are
registered for the same sensor.
Change-Id: I1491bea8c2081c4aab1feacc60add13b7aa26bb7
diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index 6c3144b..ef87e5c 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -807,29 +807,36 @@
return sensor->setDelay(connection.get(), handle, ns);
}
-status_t SensorService::flushSensor(const sp<SensorEventConnection>& connection,
- int handle) {
+status_t SensorService::flushSensor(const sp<SensorEventConnection>& connection) {
if (mInitCheck != NO_ERROR) return mInitCheck;
- SensorInterface* sensor = mSensorMap.valueFor(handle);
- if (sensor == NULL) {
- return BAD_VALUE;
+ SensorDevice& dev(SensorDevice::getInstance());
+ const int halVersion = dev.getHalDeviceVersion();
+ status_t err(NO_ERROR);
+ Mutex::Autolock _l(mLock);
+ // Loop through all sensors for this connection and call flush on each of them.
+ for (size_t i = 0; i < connection->mSensorInfo.size(); ++i) {
+ const int handle = connection->mSensorInfo.keyAt(i);
+ SensorInterface* sensor = mSensorMap.valueFor(handle);
+ if (sensor->getSensor().getReportingMode() == AREPORTING_MODE_ONE_SHOT) {
+ ALOGE("flush called on a one-shot sensor");
+ err = INVALID_OPERATION;
+ continue;
+ }
+ SensorEventConnection::FlushInfo& flushInfo = connection->mSensorInfo.editValueFor(handle);
+ if (halVersion < SENSORS_DEVICE_API_VERSION_1_1 || isVirtualSensor(handle)) {
+ // For older devices just increment pending flush count which will send a trivial
+ // flush complete event.
+ flushInfo.mPendingFlushEventsToSend++;
+ } else {
+ status_t err_flush = sensor->flush(connection.get(), handle);
+ if (err_flush == NO_ERROR) {
+ SensorRecord* rec = mActiveSensors.valueFor(handle);
+ if (rec != NULL) rec->addPendingFlushConnection(connection);
+ }
+ err = (err_flush != NO_ERROR) ? err_flush : err;
+ }
}
-
- if (!verifyCanAccessSensor(sensor->getSensor(), "Tried flushing")) {
- return BAD_VALUE;
- }
-
- if (sensor->getSensor().getReportingMode() == AREPORTING_MODE_ONE_SHOT) {
- ALOGE("flush called on a one-shot sensor");
- return INVALID_OPERATION;
- }
-
- status_t ret = sensor->flush(connection.get(), handle);
- if (ret == NO_ERROR) {
- SensorRecord* rec = mActiveSensors.valueFor(handle);
- if (rec != NULL) rec->addPendingFlushConnection(connection);
- }
- return ret;
+ return err;
}
bool SensorService::canAccessSensor(const Sensor& sensor) {
@@ -1034,7 +1041,7 @@
}
status_t SensorService::SensorEventConnection::sendEvents(
- sensors_event_t const* buffer, size_t numEvents,
+ sensors_event_t* buffer, size_t numEvents,
sensors_event_t* scratch) {
// filter out events not for this connection
size_t count = 0;
@@ -1042,10 +1049,16 @@
if (scratch) {
size_t i=0;
while (i<numEvents) {
+ // Flush complete events can be invalidated. If this event has been invalidated
+ // before, ignore and proceed to the next event.
+ if (buffer[i].flags & SENSOR_EVENT_INVALID_FLAG) {
+ ++i;
+ continue;
+ }
int32_t sensor_handle = buffer[i].sensor;
if (buffer[i].type == SENSOR_TYPE_META_DATA) {
ALOGD_IF(DEBUG_CONNECTIONS, "flush complete event sensor==%d ",
- buffer[i].meta_data.sensor);
+ buffer[i].meta_data.sensor);
// Setting sensor_handle to the correct sensor to ensure the sensor events per connection are
// filtered correctly. buffer[i].sensor is zero for meta_data events.
sensor_handle = buffer[i].meta_data.sensor;
@@ -1065,9 +1078,12 @@
if (rec && rec->getFirstPendingFlushConnection() == this) {
rec->removeFirstPendingFlushConnection();
flushInfo.mFirstFlushPending = false;
- ++i;
+ // Invalidate this flush_complete_event so that it cannot be used by other
+ // connections.
+ buffer[i].flags |= SENSOR_EVENT_INVALID_FLAG;
ALOGD_IF(DEBUG_CONNECTIONS, "First flush event for sensor==%d ",
- buffer[i].meta_data.sensor);
+ buffer[i].meta_data.sensor);
+ ++i;
continue;
}
}
@@ -1080,13 +1096,20 @@
}
do {
+ if (buffer[i].flags & SENSOR_EVENT_INVALID_FLAG) {
+ ++i;
+ continue;
+ }
if (buffer[i].type == SENSOR_TYPE_META_DATA) {
- // Check if this connection has called flush() on this sensor. Only if
- // a flush() has been explicitly called, send a flush_complete_event.
- SensorService::SensorRecord *rec = mService->getSensorRecord(sensor_handle);
- if (rec && rec->getFirstPendingFlushConnection() == this) {
+ // Check if this connection has called flush() on this sensor. Only if
+ // a flush() has been explicitly called, send a flush_complete_event.
+ SensorService::SensorRecord *rec = mService->getSensorRecord(sensor_handle);
+ if (rec && rec->getFirstPendingFlushConnection() == this) {
rec->removeFirstPendingFlushConnection();
scratch[count++] = buffer[i];
+ // Invalidate this flush_complete_event so that it cannot be used by
+ // other connections.
+ buffer[i].flags |= SENSOR_EVENT_INVALID_FLAG;
}
++i;
} else {
@@ -1333,27 +1356,7 @@
}
status_t SensorService::SensorEventConnection::flush() {
- SensorDevice& dev(SensorDevice::getInstance());
- const int halVersion = dev.getHalDeviceVersion();
- Mutex::Autolock _l(mConnectionLock);
- status_t err(NO_ERROR);
- // Loop through all sensors for this connection and call flush on each of them.
- for (size_t i = 0; i < mSensorInfo.size(); ++i) {
- const int handle = mSensorInfo.keyAt(i);
- FlushInfo& flushInfo = mSensorInfo.editValueFor(handle);
- if (halVersion < SENSORS_DEVICE_API_VERSION_1_1 || mService->isVirtualSensor(handle)) {
- // For older devices just increment pending flush count which will send a trivial
- // flush complete event.
- flushInfo.mPendingFlushEventsToSend++;
- } else {
- status_t err_flush = mService->flushSensor(this, handle);
- if (err_flush != NO_ERROR) {
- ALOGE("Flush error handle=%d %s", handle, strerror(-err_flush));
- }
- err = (err_flush != NO_ERROR) ? err_flush : err;
- }
- }
- return err;
+ return mService->flushSensor(this);
}
int SensorService::SensorEventConnection::handleEvent(int fd, int events, void* data) {