1 | // Copyright 2011 Google Inc. 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 | #include "metrics.h" |
16 | |
17 | #include <errno.h> |
18 | #include <stdio.h> |
19 | #include <string.h> |
20 | |
21 | #include <algorithm> |
22 | #include <chrono> |
23 | |
24 | #include "util.h" |
25 | |
26 | using namespace std; |
27 | |
28 | Metrics* g_metrics = NULL; |
29 | |
30 | namespace { |
31 | |
32 | /// Compute a platform-specific high-res timer value that fits into an int64. |
33 | int64_t HighResTimer() { |
34 | auto now = chrono::steady_clock::now(); |
35 | return chrono::duration_cast<chrono::steady_clock::duration>( |
36 | now.time_since_epoch()) |
37 | .count(); |
38 | } |
39 | |
40 | constexpr int64_t GetFrequency() { |
41 | // If numerator isn't 1 then we lose precision and that will need to be |
42 | // assessed. |
43 | static_assert(std::chrono::steady_clock::period::num == 1, |
44 | "Numerator must be 1" ); |
45 | return std::chrono::steady_clock::period::den / |
46 | std::chrono::steady_clock::period::num; |
47 | } |
48 | |
49 | int64_t TimerToMicros(int64_t dt) { |
50 | // dt is in ticks. We want microseconds. |
51 | return (dt * 1000000) / GetFrequency(); |
52 | } |
53 | |
54 | int64_t TimerToMicros(double dt) { |
55 | // dt is in ticks. We want microseconds. |
56 | return (dt * 1000000) / GetFrequency(); |
57 | } |
58 | |
59 | } // anonymous namespace |
60 | |
61 | ScopedMetric::ScopedMetric(Metric* metric) { |
62 | metric_ = metric; |
63 | if (!metric_) |
64 | return; |
65 | start_ = HighResTimer(); |
66 | } |
67 | ScopedMetric::~ScopedMetric() { |
68 | if (!metric_) |
69 | return; |
70 | metric_->count++; |
71 | // Leave in the timer's natural frequency to avoid paying the conversion cost |
72 | // on every measurement. |
73 | int64_t dt = HighResTimer() - start_; |
74 | metric_->sum += dt; |
75 | } |
76 | |
77 | Metric* Metrics::NewMetric(const string& name) { |
78 | Metric* metric = new Metric; |
79 | metric->name = name; |
80 | metric->count = 0; |
81 | metric->sum = 0; |
82 | metrics_.push_back(metric); |
83 | return metric; |
84 | } |
85 | |
86 | void Metrics::Report() { |
87 | int width = 0; |
88 | for (vector<Metric*>::iterator i = metrics_.begin(); |
89 | i != metrics_.end(); ++i) { |
90 | width = max((int)(*i)->name.size(), width); |
91 | } |
92 | |
93 | printf("%-*s\t%-6s\t%-9s\t%s\n" , width, |
94 | "metric" , "count" , "avg (us)" , "total (ms)" ); |
95 | for (vector<Metric*>::iterator i = metrics_.begin(); |
96 | i != metrics_.end(); ++i) { |
97 | Metric* metric = *i; |
98 | uint64_t micros = TimerToMicros(metric->sum); |
99 | double total = micros / (double)1000; |
100 | double avg = micros / (double)metric->count; |
101 | printf("%-*s\t%-6d\t%-8.1f\t%.1f\n" , width, metric->name.c_str(), |
102 | metric->count, avg, total); |
103 | } |
104 | } |
105 | |
106 | double Stopwatch::Elapsed() const { |
107 | // Convert to micros after converting to double to minimize error. |
108 | return 1e-6 * TimerToMicros(static_cast<double>(NowRaw() - started_)); |
109 | } |
110 | |
111 | uint64_t Stopwatch::NowRaw() const { |
112 | return HighResTimer(); |
113 | } |
114 | |
115 | int64_t GetTimeMillis() { |
116 | return TimerToMicros(HighResTimer()) / 1000; |
117 | } |
118 | |