LogBuffer.h revision 3c501b50b41086cde59a6811f4aa5cd3e736f5f2
1/* 2 * Copyright (C) 2012-2014 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 _LOGD_LOG_BUFFER_H__ 18#define _LOGD_LOG_BUFFER_H__ 19 20#include <sys/types.h> 21 22#include <list> 23#include <string> 24 25#include <android/log.h> 26#include <private/android_filesystem_config.h> 27#include <sysutils/SocketClient.h> 28 29#include "LogBufferElement.h" 30#include "LogStatistics.h" 31#include "LogTags.h" 32#include "LogTimes.h" 33#include "LogWhiteBlackList.h" 34 35// 36// We are either in 1970ish (MONOTONIC) or 2016+ish (REALTIME) so to 37// differentiate without prejudice, we use 1972 to delineate, earlier 38// is likely monotonic, later is real. Otherwise we start using a 39// dividing line between monotonic and realtime if more than a minute 40// difference between them. 41// 42namespace android { 43 44static bool isMonotonic(const log_time& mono) { 45 static const uint32_t EPOCH_PLUS_2_YEARS = 2 * 24 * 60 * 60 * 1461 / 4; 46 static const uint32_t EPOCH_PLUS_MINUTE = 60; 47 48 if (mono.tv_sec >= EPOCH_PLUS_2_YEARS) { 49 return false; 50 } 51 52 log_time now(CLOCK_REALTIME); 53 54 /* Timezone and ntp time setup? */ 55 if (now.tv_sec >= EPOCH_PLUS_2_YEARS) { 56 return true; 57 } 58 59 /* no way to differentiate realtime from monotonic time */ 60 if (now.tv_sec < EPOCH_PLUS_MINUTE) { 61 return false; 62 } 63 64 log_time cpu(CLOCK_MONOTONIC); 65 /* too close to call to differentiate monotonic times from realtime */ 66 if ((cpu.tv_sec + EPOCH_PLUS_MINUTE) >= now.tv_sec) { 67 return false; 68 } 69 70 /* dividing line half way between monotonic and realtime */ 71 return mono.tv_sec < ((cpu.tv_sec + now.tv_sec) / 2); 72} 73} 74 75typedef std::list<LogBufferElement*> LogBufferElementCollection; 76 77class LogBuffer { 78 LogBufferElementCollection mLogElements; 79 pthread_rwlock_t mLogElementsLock; 80 81 LogStatistics stats; 82 83 PruneList mPrune; 84 // watermark for last per log id 85 LogBufferElementCollection::iterator mLast[LOG_ID_MAX]; 86 bool mLastSet[LOG_ID_MAX]; 87 // watermark of any worst/chatty uid processing 88 typedef std::unordered_map<uid_t, LogBufferElementCollection::iterator> 89 LogBufferIteratorMap; 90 LogBufferIteratorMap mLastWorst[LOG_ID_MAX]; 91 // watermark of any worst/chatty pid of system processing 92 typedef std::unordered_map<pid_t, LogBufferElementCollection::iterator> 93 LogBufferPidIteratorMap; 94 LogBufferPidIteratorMap mLastWorstPidOfSystem[LOG_ID_MAX]; 95 96 unsigned long mMaxSize[LOG_ID_MAX]; 97 98 bool monotonic; 99 100 LogTags tags; 101 102 LogBufferElement* lastLoggedElements[LOG_ID_MAX]; 103 LogBufferElement* droppedElements[LOG_ID_MAX]; 104 void log(LogBufferElement* elem); 105 106 public: 107 LastLogTimes& mTimes; 108 109 explicit LogBuffer(LastLogTimes* times); 110 ~LogBuffer(); 111 void init(); 112 bool isMonotonic() { 113 return monotonic; 114 } 115 116 int log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid, 117 const char* msg, unsigned short len); 118 // lastTid is an optional context to help detect if the last previous 119 // valid message was from the same source so we can differentiate chatty 120 // filter types (identical or expired) 121 log_time flushTo(SocketClient* writer, const log_time& start, 122 pid_t* lastTid, // &lastTid[LOG_ID_MAX] or nullptr 123 bool privileged, bool security, 124 int (*filter)(const LogBufferElement* element, 125 void* arg) = nullptr, 126 void* arg = nullptr); 127 128 bool clear(log_id_t id, uid_t uid = AID_ROOT); 129 unsigned long getSize(log_id_t id); 130 int setSize(log_id_t id, unsigned long size); 131 unsigned long getSizeUsed(log_id_t id); 132 133 std::string formatStatistics(uid_t uid, pid_t pid, unsigned int logMask); 134 135 void enableStatistics() { 136 stats.enableStatistics(); 137 } 138 139 int initPrune(const char* cp) { 140 return mPrune.init(cp); 141 } 142 std::string formatPrune() { 143 return mPrune.format(); 144 } 145 146 std::string formatGetEventTag(uid_t uid, const char* name, 147 const char* format) { 148 return tags.formatGetEventTag(uid, name, format); 149 } 150 std::string formatEntry(uint32_t tag, uid_t uid) { 151 return tags.formatEntry(tag, uid); 152 } 153 const char* tagToName(uint32_t tag) { 154 return tags.tagToName(tag); 155 } 156 157 // helper must be protected directly or implicitly by wrlock()/unlock() 158 const char* pidToName(pid_t pid) { 159 return stats.pidToName(pid); 160 } 161 uid_t pidToUid(pid_t pid) { 162 return stats.pidToUid(pid); 163 } 164 const char* uidToName(uid_t uid) { 165 return stats.uidToName(uid); 166 } 167 void wrlock() { 168 pthread_rwlock_wrlock(&mLogElementsLock); 169 } 170 void rdlock() { 171 pthread_rwlock_rdlock(&mLogElementsLock); 172 } 173 void unlock() { 174 pthread_rwlock_unlock(&mLogElementsLock); 175 } 176 177 private: 178 static constexpr size_t minPrune = 4; 179 static constexpr size_t maxPrune = 256; 180 static const log_time pruneMargin; 181 182 void maybePrune(log_id_t id); 183 bool prune(log_id_t id, unsigned long pruneRows, uid_t uid = AID_ROOT); 184 LogBufferElementCollection::iterator erase( 185 LogBufferElementCollection::iterator it, bool coalesce = false); 186}; 187 188#endif // _LOGD_LOG_BUFFER_H__ 189