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 <utils/Mutex.h> 24 #include <utils/RefBase.h> 25 26 #include <inttypes.h> 27 #include <stdint.h> 28 29 #include <string> 30 #include <unordered_map> 31 #include <vector> 32 33 namespace android { 34 namespace automotive { 35 namespace watchdog { 36 37 using ::android::base::StringPrintf; 38 39 #define PID_FOR_INIT 1 40 41 constexpr const char kProcDirPath[] = "/proc"; 42 constexpr const char kStatFileFormat[] = "/%" PRIu32 "/stat"; 43 constexpr const char kTaskDirFormat[] = "/%" PRIu32 "/task"; 44 constexpr const char kStatusFileFormat[] = "/%" PRIu32 "/status"; 45 46 // Per-process stats. 47 struct ProcessStats { 48 std::string comm = ""; 49 uint64_t startTime = 0; // Useful when identifying PID reuse 50 uint64_t totalMajorFaults = 0; 51 int totalTasksCount = 0; 52 int ioBlockedTasksCount = 0; 53 std::string toString() const; 54 }; 55 56 // Per-UID stats. 57 struct UidProcStats { 58 uint64_t totalMajorFaults = 0; 59 int totalTasksCount = 0; 60 int ioBlockedTasksCount = 0; 61 std::unordered_map<pid_t, ProcessStats> processStatsByPid = {}; 62 std::string toString() const; 63 }; 64 65 /** 66 * Collector/parser for `/proc/[pid]/stat`, `/proc/[pid]/task/[tid]/stat` and /proc/[pid]/status` 67 * files. 68 */ 69 class UidProcStatsCollectorInterface : public RefBase { 70 public: 71 // Collects the per-uid stats from /proc directory. 72 virtual android::base::Result<void> collect() = 0; 73 // Returns the latest per-uid process stats. 74 virtual const std::unordered_map<uid_t, UidProcStats> latestStats() const = 0; 75 // Returns the delta of per-uid process stats since the last before collection. 76 virtual const std::unordered_map<uid_t, UidProcStats> deltaStats() const = 0; 77 // Returns true only when the /proc files for the init process are accessible. 78 virtual bool enabled() const = 0; 79 // Returns the /proc files common ancestor directory path. 80 virtual const std::string dirPath() const = 0; 81 }; 82 83 class UidProcStatsCollector final : public UidProcStatsCollectorInterface { 84 public: 85 explicit UidProcStatsCollector(const std::string& path = kProcDirPath) : 86 mLatestStats({}), 87 mPath(path) { 88 std::string pidStatPath = StringPrintf((mPath + kStatFileFormat).c_str(), PID_FOR_INIT); 89 std::string tidStatPath = StringPrintf((mPath + kTaskDirFormat + kStatFileFormat).c_str(), 90 PID_FOR_INIT, PID_FOR_INIT); 91 std::string pidStatusPath = StringPrintf((mPath + kStatusFileFormat).c_str(), PID_FOR_INIT); 92 93 mEnabled = !access(pidStatPath.c_str(), R_OK) && !access(tidStatPath.c_str(), R_OK) && 94 !access(pidStatusPath.c_str(), R_OK); 95 } 96 ~UidProcStatsCollector()97 ~UidProcStatsCollector() {} 98 99 android::base::Result<void> collect() override; 100 latestStats()101 const std::unordered_map<uid_t, UidProcStats> latestStats() const { 102 Mutex::Autolock lock(mMutex); 103 return mLatestStats; 104 } 105 deltaStats()106 const std::unordered_map<uid_t, UidProcStats> deltaStats() const { 107 Mutex::Autolock lock(mMutex); 108 return mDeltaStats; 109 } 110 enabled()111 bool enabled() const { return mEnabled; } 112 dirPath()113 const std::string dirPath() const { return mPath; } 114 115 private: 116 android::base::Result<std::unordered_map<uid_t, UidProcStats>> readUidProcStatsLocked() const; 117 118 /** 119 * Reads the contents of the below files: 120 * 1. Pid stat file at |mPath| + |kStatFileFormat| 121 * 2. Aggregated per-process status at |mPath| + |kStatusFileFormat| 122 * 3. Tid stat file at |mPath| + |kTaskDirFormat| + |kStatFileFormat| 123 */ 124 android::base::Result<std::tuple<uid_t, ProcessStats>> readProcessStatsLocked(pid_t pid) const; 125 126 // Makes sure only one collection is running at any given time. 127 mutable Mutex mMutex; 128 129 // Latest dump of per-UID stats. 130 std::unordered_map<uid_t, UidProcStats> mLatestStats GUARDED_BY(mMutex); 131 132 // Latest delta of per-uid stats. 133 std::unordered_map<uid_t, UidProcStats> mDeltaStats GUARDED_BY(mMutex); 134 135 /** 136 * True if the below files are accessible: 137 * 1. Pid stat file at |mPath| + |kTaskStatFileFormat| 138 * 2. Tid stat file at |mPath| + |kTaskDirFormat| + |kStatFileFormat| 139 * 3. Pid status file at |mPath| + |kStatusFileFormat| 140 * Otherwise, set to false. 141 */ 142 bool mEnabled; 143 144 /** 145 * Proc directory path. Default value is |kProcDirPath|. 146 * Updated by tests to point to a different location when needed. 147 */ 148 std::string mPath; 149 150 FRIEND_TEST(IoPerfCollectionTest, TestValidProcPidContents); 151 FRIEND_TEST(UidProcStatsCollectorTest, TestValidStatFiles); 152 FRIEND_TEST(UidProcStatsCollectorTest, TestHandlesProcessTerminationBetweenScanningAndParsing); 153 FRIEND_TEST(UidProcStatsCollectorTest, TestHandlesPidTidReuse); 154 }; 155 156 } // namespace watchdog 157 } // namespace automotive 158 } // namespace android 159 160 #endif // CPP_WATCHDOG_SERVER_SRC_UIDPROCSTATSCOLLECTOR_H_ 161