Sensor changes.

1. Some sensors can wake up the AP. Add wakelocks.
2. Handle backward compatibility for rotation vector
   heading accuracy.
3. Cleanup auto disabled sensors.
4. Fix race condition between enable and dispatch.

Change-Id: I39dddf12e208d83cd288201986ee994312555820
diff --git a/services/sensorservice/Android.mk b/services/sensorservice/Android.mk
index a1de3c5..dd698c5 100644
--- a/services/sensorservice/Android.mk
+++ b/services/sensorservice/Android.mk
@@ -20,6 +20,7 @@
 LOCAL_SHARED_LIBRARIES := \
 	libcutils \
 	libhardware \
+	libhardware_legacy \
 	libutils \
 	liblog \
 	libbinder \
diff --git a/services/sensorservice/SensorDevice.cpp b/services/sensorservice/SensorDevice.cpp
index a9e3ef4..b256cce 100644
--- a/services/sensorservice/SensorDevice.cpp
+++ b/services/sensorservice/SensorDevice.cpp
@@ -181,6 +181,12 @@
     return mSensorDevice->setDelay(mSensorDevice, handle, ns);
 }
 
+int SensorDevice::getHalDeviceVersion() const {
+    if (!mSensorDevice) return -1;
+
+    return mSensorDevice->common.version;
+}
+
 // ---------------------------------------------------------------------------
 
 status_t SensorDevice::Info::setDelayForIdent(void* ident, int64_t ns)
diff --git a/services/sensorservice/SensorDevice.h b/services/sensorservice/SensorDevice.h
index 728b6cb..b423f40 100644
--- a/services/sensorservice/SensorDevice.h
+++ b/services/sensorservice/SensorDevice.h
@@ -52,6 +52,7 @@
 public:
     ssize_t getSensorList(sensor_t const** list);
     status_t initCheck() const;
+    int getHalDeviceVersion() const;
     ssize_t poll(sensors_event_t* buffer, size_t count);
     status_t activate(void* ident, int handle, int enabled);
     status_t setDelay(void* ident, int handle, int64_t ns);
diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index e3dcd02..9ca6b45 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -38,6 +38,7 @@
 #include <gui/SensorEventQueue.h>
 
 #include <hardware/sensors.h>
+#include <hardware_legacy/power.h>
 
 #include "BatteryService.h"
 #include "CorrectedGyroSensor.h"
@@ -60,6 +61,8 @@
  *
  */
 
+const char* SensorService::WAKE_LOCK_NAME = "SensorService";
+
 SensorService::SensorService()
     : mInitCheck(NO_INIT)
 {
@@ -237,6 +240,18 @@
     return NO_ERROR;
 }
 
+void SensorService::cleanupAutoDisabledSensor(const sp<SensorEventConnection>& connection,
+        sensors_event_t const* buffer, const int count) {
+    for (int i=0 ; i<count ; i++) {
+        int handle = buffer[i].sensor;
+        if (getSensorType(handle) == SENSOR_TYPE_SIGNIFICANT_MOTION) {
+            if (connection->hasSensor(handle)) {
+                cleanupWithoutDisable(connection, handle);
+            }
+        }
+    }
+}
+
 bool SensorService::threadLoop()
 {
     ALOGD("nuSensorService thread starting...");
@@ -249,6 +264,8 @@
     const size_t vcount = mVirtualSensorList.size();
 
     ssize_t count;
+    bool wakeLockAcquired = false;
+    const int halVersion = device.getHalDeviceVersion();
     do {
         count = device.poll(buffer, numEventMax);
         if (count<0) {
@@ -256,6 +273,17 @@
             break;
         }
 
+        // Poll has returned. Hold a wakelock.
+        // Todo(): add a flag to the sensors definitions to indicate
+        // the sensors which can wake up the AP
+        for (int i = 0; i < count; i++) {
+            if (getSensorType(buffer[i].sensor) == SENSOR_TYPE_SIGNIFICANT_MOTION) {
+                 acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_NAME);
+                 wakeLockAcquired = true;
+                 break;
+            }
+        }
+
         recordLastValue(buffer, count);
 
         // handle virtual sensors
@@ -298,6 +326,17 @@
             }
         }
 
+        // handle backward compatibility for RotationVector sensor
+        if (halVersion < SENSORS_DEVICE_API_VERSION_1_0) {
+            for (int i = 0; i < count; i++) {
+                if (getSensorType(buffer[i].sensor) == SENSOR_TYPE_ROTATION_VECTOR) {
+                    // All the 4 components of the quaternion should be available
+                    // No heading accuracy. Set it to -1
+                    buffer[i].data[4] = -1;
+                }
+            }
+        }
+
         // send our events to clients...
         const SortedVector< wp<SensorEventConnection> > activeConnections(
                 getActiveConnections());
@@ -307,8 +346,14 @@
                     activeConnections[i].promote());
             if (connection != 0) {
                 connection->sendEvents(buffer, count, scratch);
+                // Some sensors need to be auto disabled after the trigger
+                cleanupAutoDisabledSensor(connection, buffer, count);
             }
         }
+
+        // We have read the data, upper layers should hold the wakelock.
+        if (wakeLockAcquired) release_wake_lock(WAKE_LOCK_NAME);
+
     } while (count >= 0 || Thread::exitPending());
 
     ALOGW("Exiting SensorService::threadLoop => aborting...");
@@ -372,6 +417,18 @@
     return result;
 }
 
+int SensorService::getSensorType(int handle) const {
+    size_t count = mUserSensorList.size();
+    for (size_t i=0 ; i<count ; i++) {
+        const Sensor& sensor(mUserSensorList[i]);
+        if (sensor.getHandle() == handle) {
+            return sensor.getType();
+        }
+    }
+    return -1;
+}
+
+
 Vector<Sensor> SensorService::getSensorList()
 {
     char value[PROPERTY_VALUE_MAX];
@@ -433,44 +490,48 @@
 
     Mutex::Autolock _l(mLock);
     SensorInterface* sensor = mSensorMap.valueFor(handle);
+    SensorRecord* rec = mActiveSensors.valueFor(handle);
+    if (rec == 0) {
+        rec = new SensorRecord(connection);
+        mActiveSensors.add(handle, rec);
+        if (sensor->isVirtual()) {
+            mActiveVirtualSensors.add(handle, sensor);
+        }
+    } else {
+        if (rec->addConnection(connection)) {
+            // this sensor is already activated, but we are adding a
+            // connection that uses it. Immediately send down the last
+            // known value of the requested sensor if it's not a
+            // "continuous" sensor.
+            if (sensor->getSensor().getMinDelay() == 0) {
+                sensors_event_t scratch;
+                sensors_event_t& event(mLastEventSeen.editValueFor(handle));
+                if (event.version == sizeof(sensors_event_t)) {
+                    connection->sendEvents(&event, 1);
+                }
+            }
+        }
+    }
+
+    if (connection->addSensor(handle)) {
+        BatteryService::enableSensor(connection->getUid(), handle);
+        // the sensor was added (which means it wasn't already there)
+        // so, see if this connection becomes active
+        if (mActiveConnections.indexOf(connection) < 0) {
+            mActiveConnections.add(connection);
+        }
+    } else {
+        ALOGW("sensor %08x already enabled in connection %p (ignoring)",
+            handle, connection.get());
+    }
+
+
+    // we are setup, now enable the sensor.
     status_t err = sensor ? sensor->activate(connection.get(), true) : status_t(BAD_VALUE);
-    if (err == NO_ERROR) {
-        SensorRecord* rec = mActiveSensors.valueFor(handle);
-        if (rec == 0) {
-            rec = new SensorRecord(connection);
-            mActiveSensors.add(handle, rec);
-            if (sensor->isVirtual()) {
-                mActiveVirtualSensors.add(handle, sensor);
-            }
-        } else {
-            if (rec->addConnection(connection)) {
-                // this sensor is already activated, but we are adding a
-                // connection that uses it. Immediately send down the last
-                // known value of the requested sensor if it's not a
-                // "continuous" sensor.
-                if (sensor->getSensor().getMinDelay() == 0) {
-                    sensors_event_t scratch;
-                    sensors_event_t& event(mLastEventSeen.editValueFor(handle));
-                    if (event.version == sizeof(sensors_event_t)) {
-                        connection->sendEvents(&event, 1);
-                    }
-                }
-            }
-        }
-        if (err == NO_ERROR) {
-            // connection now active
-            if (connection->addSensor(handle)) {
-                BatteryService::enableSensor(connection->getUid(), handle);
-                // the sensor was added (which means it wasn't already there)
-                // so, see if this connection becomes active
-                if (mActiveConnections.indexOf(connection) < 0) {
-                    mActiveConnections.add(connection);
-                }
-            } else {
-                ALOGW("sensor %08x already enabled in connection %p (ignoring)",
-                        handle, connection.get());
-            }
-        }
+
+    if (err != NO_ERROR) {
+        // enable has failed, reset our state.
+        cleanupWithoutDisable(connection, handle);
     }
     return err;
 }
@@ -481,7 +542,16 @@
     if (mInitCheck != NO_ERROR)
         return mInitCheck;
 
-    status_t err = NO_ERROR;
+    status_t err = cleanupWithoutDisable(connection, handle);
+    if (err == NO_ERROR) {
+        SensorInterface* sensor = mSensorMap.valueFor(handle);
+        err = sensor ? sensor->activate(connection.get(), false) : status_t(BAD_VALUE);
+    }
+    return err;
+}
+
+status_t SensorService::cleanupWithoutDisable(const sp<SensorEventConnection>& connection,
+        int handle) {
     Mutex::Autolock _l(mLock);
     SensorRecord* rec = mActiveSensors.valueFor(handle);
     if (rec) {
@@ -498,10 +568,9 @@
             mActiveVirtualSensors.removeItem(handle);
             delete rec;
         }
-        SensorInterface* sensor = mSensorMap.valueFor(handle);
-        err = sensor ? sensor->activate(connection.get(), false) : status_t(BAD_VALUE);
+        return NO_ERROR;
     }
-    return err;
+    return BAD_VALUE;
 }
 
 status_t SensorService::setEventRate(const sp<SensorEventConnection>& connection,
diff --git a/services/sensorservice/SensorService.h b/services/sensorservice/SensorService.h
index 18591bf..25e5f76 100644
--- a/services/sensorservice/SensorService.h
+++ b/services/sensorservice/SensorService.h
@@ -53,6 +53,7 @@
    friend class BinderService<SensorService>;
 
    static const nsecs_t MINIMUM_EVENTS_PERIOD =   1000000; // 1000 Hz
+   static const char* WAKE_LOCK_NAME;
 
             SensorService();
     virtual ~SensorService();
@@ -109,10 +110,15 @@
     DefaultKeyedVector<int, SensorInterface*> getActiveVirtualSensors() const;
 
     String8 getSensorName(int handle) const;
+    int getSensorType(int handle) const;
     void recordLastValue(sensors_event_t const * buffer, size_t count);
     static void sortEventBuffer(sensors_event_t* buffer, size_t count);
     void registerSensor(SensorInterface* sensor);
     void registerVirtualSensor(SensorInterface* sensor);
+    status_t cleanupWithoutDisable(const sp<SensorEventConnection>& connection,
+        int handle);
+    void cleanupAutoDisabledSensor(const sp<SensorEventConnection>& connection,
+        sensors_event_t const* buffer, const int count);
 
     // constants
     Vector<Sensor> mSensorList;