1/*
2 * Copyright (C) 2016 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 CHRE_PLATFORM_TIME_H_
18#define CHRE_PLATFORM_TIME_H_
19
20#include <cstdint>
21
22#include "chre/util/time.h"
23
24namespace chre {
25
26class SystemTime {
27 public:
28  /**
29   * Initializes the system clock. This must be called as part of the
30   * initialization of the runtime.
31   */
32  static void init();
33
34  /**
35   * Obtains a monotonic time reference relative to an arbitrary starting point.
36   * There is no mandate that getMonotonicTime and getUptime be different.
37   *
38   * @return The time of the system.
39   */
40  static Nanoseconds getMonotonicTime();
41
42  /**
43   * Obtains the uptime of CHRE relative to CHRE initialization. There is no
44   * mandate that getUptime and getMonotonicTime be different.
45   *
46   * @return The uptime of CHRE.
47   */
48  static Nanoseconds getUptime();
49
50  /**
51   * Returns the estimated offset between the host and CHRE time. The offset is
52   * defined as the host time minus the CHRE time.
53   *
54   * @return The current estimated offset in nanoseconds.
55   */
56  static int64_t getEstimatedHostTimeOffset();
57};
58
59}  // namespace chre
60
61#endif  // CHRE_PLATFORM_TIME_H_
62