1 /*
2 * Copyright (C) 2021 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 #include "DevfreqStateResidencyDataProvider.h"
17
18 #include <android-base/logging.h>
19
20 static const std::string nameSuffix = "-DVFS";
21 static const std::string pathSuffix = "/time_in_state";
22
23 namespace aidl {
24 namespace android {
25 namespace hardware {
26 namespace power {
27 namespace stats {
28
DevfreqStateResidencyDataProvider(const std::string & name,const std::string & path)29 DevfreqStateResidencyDataProvider::DevfreqStateResidencyDataProvider(const std::string& name,
30 const std::string& path) : mName(name + nameSuffix), mPath(path + pathSuffix) {}
31
extractNum(const char * str,char ** str_end,int base,int64_t * num)32 bool DevfreqStateResidencyDataProvider::extractNum(const char *str, char **str_end, int base,
33 int64_t* num) {
34 // errno can be set to any non-zero value by a library function call
35 // regardless of whether there was an error, so it needs to be cleared
36 // in order to check the error set by strtoll
37 errno = 0;
38 *num = std::strtoll(str, str_end, base);
39 return (errno != ERANGE);
40 }
41
parseTimeInState()42 std::vector<std::pair<int64_t, int64_t>> DevfreqStateResidencyDataProvider::parseTimeInState() {
43 // Using FILE* instead of std::ifstream for performance reasons
44 std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(mPath.c_str(), "r"), fclose);
45 if (!fp) {
46 PLOG(ERROR) << "Failed to open file " << mPath;
47 return {};
48 }
49
50 std::vector<std::pair<int64_t, int64_t>> timeInState;
51
52 char *line = nullptr;
53 size_t len = 0;
54 while (getline(&line, &len, fp.get()) != -1) {
55 char* pEnd;
56 int64_t frequencyHz, totalTimeMs;
57 if (!extractNum(line, &pEnd, 10, &frequencyHz) ||
58 !extractNum(pEnd, &pEnd, 10, &totalTimeMs)) {
59 PLOG(ERROR) << "Failed to parse " << mPath;
60 free(line);
61 return {};
62 }
63
64 timeInState.push_back({frequencyHz, totalTimeMs});
65 }
66
67 free(line);
68 return timeInState;
69 }
70
getStateResidencies(std::unordered_map<std::string,std::vector<StateResidency>> * residencies)71 bool DevfreqStateResidencyDataProvider::getStateResidencies(
72 std::unordered_map<std::string, std::vector<StateResidency>> *residencies) {
73 std::vector<std::pair<int64_t, int64_t>> timeInState = parseTimeInState();
74
75 if (timeInState.empty()) {
76 return false;
77 }
78
79 int32_t id = 0;
80 std::vector<StateResidency> stateResidencies;
81 for (const auto[frequencyHz, totalTimeMs] : timeInState) {
82 StateResidency s = {.id = id++, .totalTimeInStateMs = totalTimeMs};
83 stateResidencies.push_back(s);
84 }
85
86 residencies->emplace(mName, stateResidencies);
87 return true;
88 }
89
getInfo()90 std::unordered_map<std::string, std::vector<State>> DevfreqStateResidencyDataProvider::getInfo() {
91 std::vector<std::pair<int64_t, int64_t>> timeInState = parseTimeInState();
92
93 if (timeInState.empty()) {
94 return {};
95 }
96
97 int32_t id = 0;
98 std::vector<State> states;
99 for (const auto[frequencyHz, totalTimeMs] : timeInState) {
100 State s = {.id = id++, .name = std::to_string(frequencyHz / 1000) + "MHz"};
101 states.push_back(s);
102 }
103
104 return {{mName, states}};
105 }
106
107 } // namespace stats
108 } // namespace power
109 } // namespace hardware
110 } // namespace android
111 } // namespace aidl
112