1 /* 2 * Copyright (c) 2020, 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 CPP_WATCHDOG_SERVER_SRC_UIDPROCSTATSCOLLECTOR_H_ 18 #define CPP_WATCHDOG_SERVER_SRC_UIDPROCSTATSCOLLECTOR_H_ 19 20 #include <android-base/result.h> 21 #include <android-base/stringprintf.h> 22 #include <gtest/gtest_prod.h> 23 #include <meminfo/procmeminfo.h> 24 #include <utils/Mutex.h> 25 #include <utils/RefBase.h> 26 27 #include <android_car_feature.h> 28 #include <inttypes.h> 29 #include <stdint.h> 30 #include <unistd.h> 31 32 #include <string> 33 #include <unordered_map> 34 #include <vector> 35 36 namespace android { 37 namespace automotive { 38 namespace watchdog { 39 40 using ::android::base::StringPrintf; 41 42 #define PID_FOR_INIT 1 43 44 constexpr const char kProcDirPath[] = "/proc"; 45 constexpr const char kStatFileFormat[] = "/%" PRIu32 "/stat"; 46 constexpr const char kTaskDirFormat[] = "/%" PRIu32 "/task"; 47 constexpr const char kStatusFileFormat[] = "/%" PRIu32 "/status"; 48 constexpr const char kSmapsRollupFileFormat[] = "/%" PRIu32 "/smaps_rollup"; 49 constexpr const char kStatmFileFormat[] = "/%" PRIu32 "/statm"; 50 constexpr const char kTimeInStateFileFormat[] = "/%" PRIu32 "/time_in_state"; 51 52 /** 53 * Per-pid/tid stats. 54 * 55 * The int64_t type is used due to AIDL limitations representing long field values. 56 */ 57 struct PidStat { 58 std::string comm = ""; 59 std::string state = ""; 60 int64_t startTimeMillis = 0; 61 int64_t cpuTimeMillis = 0; 62 uint64_t majorFaults = 0; 63 }; 64 65 // Per-process stats. 66 struct ProcessStats { 67 std::string comm = ""; 68 int64_t startTimeMillis = 0; // Useful when identifying PID reuse 69 int64_t cpuTimeMillis = 0; 70 // Stats in below fields are aggregated across all threads 71 uint64_t totalCpuCycles = 0; 72 uint64_t totalMajorFaults = 0; 73 int totalTasksCount = 0; 74 int ioBlockedTasksCount = 0; 75 std::unordered_map<pid_t, uint64_t> cpuCyclesByTid = {}; 76 uint64_t rssKb = 0; 77 /** 78 * PSS/SwapPss will be missing when the smaps_rollup file is not supported or missing for 79 * a process. In such cases, use RSS to rank the processes by memory usage. 80 */ 81 uint64_t pssKb = 0; 82 /** 83 * Unique set size is the portion of memory unique (private) to the process. Unshared memory 84 * is reported as USS. 85 * 86 * PSS - USS = Proportional portion of memory shared with one or more process. 87 * RSS - USS = Total portion of memory shared with one or more process. 88 */ 89 uint64_t ussKb = 0; 90 uint64_t swapPssKb = 0; 91 std::string toString() const; 92 }; 93 94 // Per-UID stats. 95 struct UidProcStats { 96 int64_t cpuTimeMillis = 0; 97 uint64_t cpuCycles = 0; 98 uint64_t totalMajorFaults = 0; 99 int totalTasksCount = 0; 100 int ioBlockedTasksCount = 0; 101 /** 102 * When smaps_rollup is supported by the Kernel, totalPssKb will be populated. When this 103 * feature is not supported, use totalRssKb to rank the UIDs. 104 * 105 * totalRssKb counts total shared memory from each of the processes. Thus leading to counting 106 * the same portion of memory more than once: 107 * 108 * For example, if N processes share X amount of memory and a subset of the processes (say M) 109 * belong to same UID, then 110 * 1. totalRssKb across all UIDs += Unique memory for N processes + (N * X). 111 * 2. totalRssKb for the UID += Unique memory for M processes + (M * X). 112 */ 113 uint64_t totalRssKb = 0; 114 uint64_t totalPssKb = 0; 115 // TODO(b/333212872): Handles totalUssKb, totalSwapPssKb calculation logic here. 116 std::unordered_map<pid_t, ProcessStats> processStatsByPid = {}; 117 std::string toString() const; 118 }; 119 120 /** 121 * Collector/parser for `/proc/[pid]/stat`, `/proc/[pid]/task/[tid]/stat` and /proc/[pid]/status` 122 * files. 123 */ 124 class UidProcStatsCollectorInterface : public RefBase { 125 public: 126 // Initializes the collector. 127 virtual void init() = 0; 128 // Collects the per-uid stats from /proc directory. 129 virtual android::base::Result<void> collect() = 0; 130 // Returns the latest per-uid process stats. 131 virtual const std::unordered_map<uid_t, UidProcStats> latestStats() const = 0; 132 // Returns the delta of per-uid process stats since the last before collection. 133 virtual const std::unordered_map<uid_t, UidProcStats> deltaStats() const = 0; 134 // Returns true only when the /proc files for the init process are accessible. 135 virtual bool enabled() const = 0; 136 // Returns the /proc files common ancestor directory path. 137 virtual const std::string dirPath() const = 0; 138 }; 139 140 class UidProcStatsCollector final : public UidProcStatsCollectorInterface { 141 public: 142 // TODO(b/333722043): Once carwatchdogd has sys_ptrace capability, set mIsSmapsRollupSupported 143 // field from `android::meminfo::IsSmapsRollupSupported()`. 144 // Disabling smaps_rollup support because this file cannot be read without sys_ptrace 145 // capability. UidProcStatsCollector()146 UidProcStatsCollector() : 147 UidProcStatsCollector(kProcDirPath, /*isSmapsRollupSupported=*/false) {} 148 // Used by tests. 149 UidProcStatsCollector(const std::string& path, bool isSmapsRollupSupported); 150 ~UidProcStatsCollector()151 ~UidProcStatsCollector() {} 152 153 void init() override; 154 155 android::base::Result<void> collect() override; 156 latestStats()157 const std::unordered_map<uid_t, UidProcStats> latestStats() const { 158 Mutex::Autolock lock(mMutex); 159 return mLatestStats; 160 } 161 deltaStats()162 const std::unordered_map<uid_t, UidProcStats> deltaStats() const { 163 Mutex::Autolock lock(mMutex); 164 return mDeltaStats; 165 } 166 enabled()167 bool enabled() const { 168 Mutex::Autolock lock(mMutex); 169 return mIsEnabled; 170 } 171 dirPath()172 const std::string dirPath() const { return mPath; } 173 174 static android::base::Result<PidStat> readStatFileForPid(pid_t pid); 175 176 static android::base::Result<std::tuple<uid_t, pid_t>> readPidStatusFileForPid(pid_t pid); 177 178 private: 179 android::base::Result<std::unordered_map<uid_t, UidProcStats>> readUidProcStatsLocked() const; 180 181 /** 182 * Reads the contents of the below files: 183 * 1. Pid stat file at |mPath| + |kStatFileFormat| 184 * 2. Aggregated per-process status at |mPath| + |kStatusFileFormat| 185 * 3. Tid stat file at |mPath| + |kTaskDirFormat| + |kStatFileFormat| 186 */ 187 android::base::Result<std::tuple<uid_t, ProcessStats>> readProcessStatsLocked(pid_t pid) const; 188 189 /** 190 * Reads the smaps rollup file and populates the ProcessStats pointer with info for the given 191 * pid. 192 * Returns true and updates the out pointer only when the read is successful. 193 * Returns false when either the smaps_rollup file is not supported or not available for 194 * the process. When the process terminates while reading, the file won't be available. 195 */ 196 bool readSmapsRollup(pid_t pid, ProcessStats* processStatsOut) const; 197 198 size_t mPageSizeKb; 199 200 // Tracks memory profiling feature flag. 201 bool mIsMemoryProfilingEnabled; 202 203 // Tracks smaps rollup support in the Kernel. 204 bool mIsSmapsRollupSupported; 205 206 // Number of milliseconds per clock cycle. 207 int32_t mMillisPerClockTick; 208 209 /** 210 * Proc directory path. Default value is |kProcDirPath|. 211 * 212 * Updated by tests to point to a different location when needed. 213 */ 214 std::string mPath; 215 216 // Makes sure only one collection is running at any given time. 217 mutable Mutex mMutex; 218 219 /** 220 * True if the below files are accessible: 221 * 1. Pid stat file at |mPath| + |kStatFileFormat| 222 * 2. Tid stat file at |mPath| + |kTaskDirFormat| + |kStatFileFormat| 223 * 3. Pid status file at |mPath| + |kStatusFileFormat| 224 * 4. Pid statm file at |mPath| + |kStatmFileFormat| 225 * 226 * Otherwise, set to false. 227 */ 228 bool mIsEnabled GUARDED_BY(mMutex); 229 230 /** 231 * True if the tid time_in_state file at |mPath| + |kTaskDirFormat| + |kTimeInStateFileFormat| 232 * is available. 233 */ 234 bool mIsTimeInStateEnabled GUARDED_BY(mMutex); 235 236 // Latest dump of per-UID stats. 237 std::unordered_map<uid_t, UidProcStats> mLatestStats GUARDED_BY(mMutex); 238 239 // Latest delta of per-uid stat 240 std::unordered_map<uid_t, UidProcStats> mDeltaStats GUARDED_BY(mMutex); 241 242 FRIEND_TEST(PerformanceProfilerTest, TestValidProcPidContents); 243 FRIEND_TEST(UidProcStatsCollectorTest, TestValidStatFiles); 244 FRIEND_TEST(UidProcStatsCollectorTest, TestHandlesProcessTerminationBetweenScanningAndParsing); 245 FRIEND_TEST(UidProcStatsCollectorTest, TestHandlesPidTidReuse); 246 }; 247 248 } // namespace watchdog 249 } // namespace automotive 250 } // namespace android 251 252 #endif // CPP_WATCHDOG_SERVER_SRC_UIDPROCSTATSCOLLECTOR_H_ 253