1 /* Copyright 2019 Google LLC. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #ifndef RUY_RUY_TIME_H_
17 #define RUY_RUY_TIME_H_
18 
19 #include <chrono>  // NOLINT(build/c++11)
20 #include <cstdint>  // IWYU pragma: keep
21 #include <ratio>    // NOLINT(build/c++11)
22 
23 #ifdef __linux__
24 #include <sys/time.h>
25 // IWYU pragma: no_include <type_traits>
26 
27 #include <ctime>
28 #endif
29 
30 namespace ruy {
31 
32 using InternalDefaultClock = std::chrono::steady_clock;
33 
34 using TimePoint = InternalDefaultClock::time_point;
35 using Duration = InternalDefaultClock::duration;
36 
37 template <typename RepresentationType>
DurationFromSeconds(RepresentationType representation)38 Duration DurationFromSeconds(RepresentationType representation) {
39   return std::chrono::duration_cast<Duration>(
40       std::chrono::duration<RepresentationType>(representation));
41 }
42 
43 template <typename RepresentationType>
DurationFromMilliseconds(RepresentationType representation)44 Duration DurationFromMilliseconds(RepresentationType representation) {
45   return std::chrono::duration_cast<Duration>(
46       std::chrono::duration<RepresentationType, std::milli>(representation));
47 }
48 
49 template <typename RepresentationType>
DurationFromNanoseconds(RepresentationType representation)50 Duration DurationFromNanoseconds(RepresentationType representation) {
51   return std::chrono::duration_cast<Duration>(
52       std::chrono::duration<RepresentationType, std::nano>(representation));
53 }
54 
ToFloatSeconds(const Duration & duration)55 inline float ToFloatSeconds(const Duration& duration) {
56   return std::chrono::duration_cast<std::chrono::duration<float>>(duration)
57       .count();
58 }
59 
ToFloatMilliseconds(const Duration & duration)60 inline float ToFloatMilliseconds(const Duration& duration) {
61   return std::chrono::duration_cast<std::chrono::duration<float, std::milli>>(
62              duration)
63       .count();
64 }
65 
ToInt64Nanoseconds(const Duration & duration)66 inline std::int64_t ToInt64Nanoseconds(const Duration& duration) {
67   return std::chrono::duration_cast<
68              std::chrono::duration<std::int64_t, std::nano>>(duration)
69       .count();
70 }
71 
Now()72 inline TimePoint Now() { return InternalDefaultClock::now(); }
73 
CoarseNow()74 inline TimePoint CoarseNow() {
75 #ifdef __linux__
76   timespec t;
77   clock_gettime(CLOCK_MONOTONIC_COARSE, &t);
78   return TimePoint(
79       DurationFromNanoseconds(1000000000LL * t.tv_sec + t.tv_nsec));
80 #else
81   return Now();
82 #endif
83 }
84 
85 }  // namespace ruy
86 
87 #endif  // RUY_RUY_TIME_H_
88