HardwarePropertiesManager.java revision 965ecbbb3eb19007690c333ab3aa05e380deb633 
1/*
2 * Copyright (C) 2015 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 */
16package android.os;
17
18import android.annotation.IntDef;
19import android.annotation.NonNull;
20import java.lang.annotation.Retention;
21import java.lang.annotation.RetentionPolicy;
22
23
24/**
25 * The HardwarePropertiesManager class provides a mechanism of accessing hardware state of a
26 * device: CPU, GPU and battery temperatures, CPU usage per core, fan speed, etc.
27 */
28public class HardwarePropertiesManager {
29
30    private static final String TAG = HardwarePropertiesManager.class.getSimpleName();
31
32    private static native void nativeInit();
33
34    private static native float[] nativeGetFanSpeeds();
35    private static native float[] nativeGetDeviceTemperatures(int type);
36    private static native CpuUsageInfo[] nativeGetCpuUsages();
37
38    @Retention(RetentionPolicy.SOURCE)
39    @IntDef({
40        DEVICE_TEMPERATURE_CPU, DEVICE_TEMPERATURE_GPU, DEVICE_TEMPERATURE_BATTERY
41    })
42    public @interface DeviceTemperatureType {}
43
44    /**
45     * Device temperature types. These must match the values in
46     * frameworks/native/include/hardwareproperties/HardwarePropertiesManager.h
47     */
48    /** Temperature of CPUs in Celsius. */
49    public static final int DEVICE_TEMPERATURE_CPU = 0;
50
51    /** Temperature of GPUs in Celsius. */
52    public static final int DEVICE_TEMPERATURE_GPU = 1;
53
54    /** Temperature of battery in Celsius. */
55    public static final int DEVICE_TEMPERATURE_BATTERY = 2;
56
57    /** @hide */
58    public HardwarePropertiesManager() {
59        nativeInit();
60    }
61
62    /**
63     * Return an array of device temperatures in Celsius.
64     *
65     * @param type type of requested device temperature, one of {@link #DEVICE_TEMPERATURE_CPU},
66     * {@link #DEVICE_TEMPERATURE_GPU} or {@link #DEVICE_TEMPERATURE_BATTERY}.
67     * @return an array of requested float device temperatures.
68     *         Empty if platform doesn't provide the queried temperature.
69     *
70     * @throws IllegalArgumentException if an incorrect temperature type is queried.
71    */
72    public @NonNull float[] getDeviceTemperatures(@DeviceTemperatureType int type) {
73        switch (type) {
74        case DEVICE_TEMPERATURE_CPU:
75        case DEVICE_TEMPERATURE_GPU:
76        case DEVICE_TEMPERATURE_BATTERY:
77            return nativeGetDeviceTemperatures(type);
78        default:
79            throw new IllegalArgumentException();
80        }
81    }
82
83    /**
84     * Return an array of CPU usage info for each core.
85     *
86     * @return an array of {@link android.os.CpuUsageInfo} for each core.
87     *         Empty if CPU usage is not supported on this system.
88     */
89    public @NonNull CpuUsageInfo[] getCpuUsages() {
90        return nativeGetCpuUsages();
91    }
92
93    /**
94     * Return an array of fan speeds in RPM.
95     *
96     * @return an arrat of float fan speeds. Empty if there is no fans or fan speed
97     *         not supported on this system.
98     */
99    public @NonNull float[] getFanSpeeds() {
100        return nativeGetFanSpeeds();
101    }
102}
103