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 #pragma once
18 
19 #include <chrono>
20 #include <sstream>
21 
22 #if __cplusplus > 201103L && !defined(__WIN32)  // C++14
23 using namespace std::chrono_literals;
24 #endif
25 
26 namespace android {
27 namespace base {
28 
29 // A std::chrono clock based on CLOCK_BOOTTIME.
30 class boot_clock {
31  public:
32   typedef std::chrono::nanoseconds duration;
33   typedef std::chrono::time_point<boot_clock, duration> time_point;
34 
35   static time_point now();
36 };
37 
38 class Timer {
39  public:
Timer()40   Timer() : start_(boot_clock::now()) {}
41 
duration()42   std::chrono::milliseconds duration() const {
43     return std::chrono::duration_cast<std::chrono::milliseconds>(boot_clock::now() - start_);
44   }
45 
46  private:
47   boot_clock::time_point start_;
48 };
49 
50 std::ostream& operator<<(std::ostream& os, const Timer& t);
51 
52 }  // namespace base
53 }  // namespace android
54