1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ANDROID_SENSOR_DEVICE_UTIL
18 #define ANDROID_SENSOR_DEVICE_UTIL
19
20 #include <android/hidl/manager/1.0/IServiceNotification.h>
21 #include <hardware/sensors.h>
22
23 #include <cmath>
24 #include <condition_variable>
25 #include <thread>
26
27 using ::android::hardware::hidl_string;
28 using ::android::hardware::Return;
29 using ::android::hidl::manager::V1_0::IServiceNotification;
30
31 namespace android {
32 namespace SensorDeviceUtils {
33
34 // Quantizes a single value using a sensor's resolution.
quantizeValue(float * value,double resolution)35 inline void quantizeValue(float *value, double resolution) {
36 // Increase the value of the sensor's nominal resolution to ensure that
37 // sensor accuracy improvements, like runtime calibration, are not masked
38 // during requantization.
39 double incRes = 0.125 * resolution;
40 *value = round(static_cast<double>(*value) / incRes) * incRes;
41 }
42
43 // Ensures a sensor event doesn't provide values finer grained than its sensor resolution allows.
44 void quantizeSensorEventValues(sensors_event_t *event, float resolution);
45
46 // Provides a default resolution for simple sensor types if one wasn't provided by the HAL.
47 float defaultResolutionForType(int type);
48
49 class HidlServiceRegistrationWaiter : public IServiceNotification {
50 public:
51
52 HidlServiceRegistrationWaiter();
53
54 Return<void> onRegistration(const hidl_string &fqName,
55 const hidl_string &name,
56 bool preexisting) override;
57
58 void reset();
59
60 /**
61 * Wait for service restart
62 *
63 * @return true if service is restart since last reset(); false otherwise.
64 */
65 bool wait();
66 protected:
67 void onFirstRef() override;
68 private:
69 bool mRegistered;
70
71 std::mutex mLock;
72 std::condition_variable mCondition;
73 bool mRestartObserved;
74 };
75
76 } // namespace SensorDeviceUtils
77 } // namespace android;
78
79 #endif // ANDROID_SENSOR_SERVICE_UTIL
80