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_BASE_CHRONO_UTILS_H 18 #define ANDROID_BASE_CHRONO_UTILS_H 19 20 #include <chrono> 21 #include <sstream> 22 23 using namespace std::chrono_literals; 24 25 namespace android { 26 namespace base { 27 28 // A std::chrono clock based on CLOCK_BOOTTIME. 29 class boot_clock { 30 public: 31 typedef std::chrono::nanoseconds duration; 32 typedef std::chrono::time_point<boot_clock, duration> time_point; 33 34 static time_point now(); 35 }; 36 37 class Timer { 38 public: Timer()39 Timer() : start_(boot_clock::now()) {} 40 duration()41 std::chrono::milliseconds duration() const { 42 return std::chrono::duration_cast<std::chrono::milliseconds>(boot_clock::now() - start_); 43 } 44 45 private: 46 boot_clock::time_point start_; 47 }; 48 49 std::ostream& operator<<(std::ostream& os, const Timer& t); 50 51 } // namespace base 52 } // namespace android 53 54 #endif // ANDROID_BASE_CHRONO_UTILS_H 55