1 /*
2 * Copyright 2019 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 <cmath>
21 #include <functional>
22 #include <string>
23
24 #include <cutils/compiler.h>
25 #include <utils/Trace.h>
26
27 namespace android {
28
29 namespace {
30 template <class Rep, class Period>
signbit(std::chrono::duration<Rep,Period> v)31 bool signbit(std::chrono::duration<Rep, Period> v) {
32 return std::signbit(std::chrono::duration_cast<std::chrono::nanoseconds>(v).count());
33 }
34
35 template <typename Enum, typename std::enable_if<std::is_enum<Enum>::value>::type* = nullptr>
signbit(Enum e)36 bool signbit(Enum e) {
37 return std::signbit(static_cast<typename std::underlying_type<Enum>::type>(e));
38 }
39
40 template <typename T, typename std::enable_if<!std::is_enum<T>::value>::type* = nullptr>
signbit(T t)41 bool signbit(T t) {
42 return std::signbit(t);
43 }
44
45 template <typename T>
to_int64(T v)46 int64_t to_int64(T v) {
47 return int64_t(v);
48 }
49
50 template <class Rep, class Period>
to_int64(std::chrono::duration<Rep,Period> v)51 int64_t to_int64(std::chrono::duration<Rep, Period> v) {
52 return int64_t(v.count());
53 }
54 } // namespace
55
56 template <typename T>
57 class TracedOrdinal {
58 public:
59 static_assert(std::is_same<bool, T>() || (std::is_signed<T>() && std::is_integral<T>()) ||
60 std::is_same<std::chrono::nanoseconds, T>() || std::is_enum<T>(),
61 "Type is not supported. Please test it with systrace before adding "
62 "it to the list.");
63
TracedOrdinal(std::string name,T initialValue)64 TracedOrdinal(std::string name, T initialValue)
65 : mName(std::move(name)), mHasGoneNegative(signbit(initialValue)), mData(initialValue) {
66 trace();
67 }
68
get()69 T get() const { return mData; }
70
T()71 operator T() const { return get(); }
72
73 TracedOrdinal& operator=(T other) {
74 mData = other;
75 mHasGoneNegative = mHasGoneNegative || signbit(mData);
76 trace();
77 return *this;
78 }
79
80 private:
trace()81 void trace() {
82 if (CC_LIKELY(!ATRACE_ENABLED())) {
83 return;
84 }
85
86 if (mNameNegative.empty()) {
87 mNameNegative = mName + "Negative";
88 }
89
90 if (!signbit(mData)) {
91 ATRACE_INT64(mName.c_str(), to_int64(mData));
92 if (mHasGoneNegative) {
93 ATRACE_INT64(mNameNegative.c_str(), 0);
94 }
95 } else {
96 ATRACE_INT64(mNameNegative.c_str(), -to_int64(mData));
97 ATRACE_INT64(mName.c_str(), 0);
98 }
99 }
100
101 const std::string mName;
102 std::string mNameNegative;
103 bool mHasGoneNegative;
104 T mData;
105 };
106
107 } // namespace android
108