Fix a race condition in sensormanager
the per-connection state assumed the main sensorservice
lock was held during access. This is however not true while
pre-processing the events just before sending them to clients.
Therefore, there was a small window during which this state
could be modified while being used.
we now have an internal lock that protects this state.
Change-Id: I594680f20f09d6a4f1f38f093a1d3f650dcef1be
diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index b5e73ac..22a45df 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -464,6 +464,7 @@
}
bool SensorService::SensorEventConnection::addSensor(int32_t handle) {
+ Mutex::Autolock _l(mConnectionLock);
if (mSensorInfo.indexOfKey(handle) <= 0) {
SensorInfo info;
mSensorInfo.add(handle, info);
@@ -473,6 +474,7 @@
}
bool SensorService::SensorEventConnection::removeSensor(int32_t handle) {
+ Mutex::Autolock _l(mConnectionLock);
if (mSensorInfo.removeItem(handle) >= 0) {
return true;
}
@@ -480,16 +482,19 @@
}
bool SensorService::SensorEventConnection::hasSensor(int32_t handle) const {
+ Mutex::Autolock _l(mConnectionLock);
return mSensorInfo.indexOfKey(handle) >= 0;
}
bool SensorService::SensorEventConnection::hasAnySensor() const {
+ Mutex::Autolock _l(mConnectionLock);
return mSensorInfo.size() ? true : false;
}
status_t SensorService::SensorEventConnection::setEventRateLocked(
int handle, nsecs_t ns)
{
+ Mutex::Autolock _l(mConnectionLock);
ssize_t index = mSensorInfo.indexOfKey(handle);
if (index >= 0) {
SensorInfo& info = mSensorInfo.editValueFor(handle);
@@ -506,6 +511,7 @@
// filter out events not for this connection
size_t count = 0;
if (scratch) {
+ Mutex::Autolock _l(mConnectionLock);
size_t i=0;
while (i<numEvents) {
const int32_t curr = buffer[i].sensor;