Merge "Prevent stale event from being delivered to client" into qt-dev

            ALOGD_IF(DEBUG_CONNECTIONS, "... and it was the last connection");

            mActiveSensors.removeItemsAt(i, 1);

            mActiveVirtualSensors.erase(handle);

            // If this is the last connection, then mark the RecentEventLogger as stale. This is

            // critical for on-change events since the previous event is sent to a client if the

            // sensor is already active. If two clients request the sensor at the same time, one

            // of the clients would receive a stale event.

            auto logger = mRecentEvent.find(handle);

            if (logger != mRecentEvent.end()) {

                logger->second->setLastEventStale();

            }

            delete rec;

            size--;

        } else {

        if (sensor->isVirtual()) {

            mActiveVirtualSensors.emplace(handle);

        }

        // There was no SensorRecord for this sensor which means it was previously disabled. Mark

        // the recent event as stale to ensure that the previous event is not sent to a client. This

        // ensures on-change events that were generated during a previous sensor activation are not

        // erroneously sent to newly connected clients, especially if a second client registers for

        // an on-change sensor before the first client receives the updated event. Once an updated

        // event is received, the recent events will be marked as current, and any new clients will

        // immediately receive the most recent event.

        if (sensor->getSensor().getReportingMode() == AREPORTING_MODE_ON_CHANGE) {

            auto logger = mRecentEvent.find(handle);

            if (logger != mRecentEvent.end()) {

                logger->second->setLastEventStale();

            }

        }

    } else {

        if (rec->addConnection(connection)) {

            // this sensor is already activated, but we are adding a connection that uses it.