eventlog java_Android EventLog含义

一. 概述

在调试分析Android的过程中，比较常用的地查看EventLog，非常简洁明了地展现当前Activity各种状态，当然不至于此，比如还有window的信息。那么本文就列举以下am相关的tags含义。

本文涉及的源码类有EventLog.java, EventLogTags.java，另外tags格式的定义位于文件/system/etc/event-log-tags。

如果在终端输入：

logcat -b events

那么会输出大量类似这样的信息：

06-01 13:44:55.518 7361 8289 I am_create_service: [0,111484394,.StatService,10094,7769]

06-01 13:44:55.540 7361 8343 I am_proc_bound: [0,3976,com.android.providers.calendar]

06-01 13:44:55.599 7361 8033 I am_create_service: [0,61349752,.UpdateService,10034,1351]

06-01 13:44:55.625 7361 7774 I am_destroy_service: [0,61349752,1351]

...

通过字面意思，就能得到不少信息量，比如am_create_service，创建service，但是后面括号中内容的具体含义，其实有很高的价值。 接下来通过一张表格来展示含义。

二. EventLog

2.1 ActivityManager

Num

TagName

格式

功能

30001

am_finish_activity

User,Token,TaskID,ComponentName,Reason

30002

am_task_to_front

User,Task

30003

am_new_intent

User,Token,TaskID,ComponentName,Action,MIMEType,URI,Flags

30004

am_create_task

User ,Task ID

30005

am_create_activity

User ,Token ,TaskID ,ComponentName,Action,MIMEType,URI,Flags

30006

am_restart_activity

User ,Token ,TaskID,ComponentName

30007

am_resume_activity

User ,Token ,TaskID,ComponentName

30008

am_anr

User ,pid ,Package Name,Flags ,reason

ANR

30009

am_activity_launch_time

User ,Token ,ComponentName,time

30010

am_proc_bound

User ,PID ,ProcessName

30011

am_proc_died

User ,PID ,ProcessName

30012

am_failed_to_pause

User ,Token ,Wanting to pause,Currently pausing

30013

am_pause_activity

User ,Token ,ComponentName

30014

am_proc_start

User ,PID ,UID ,ProcessName,Type,Component

30015

am_proc_bad

User ,UID ,ProcessName

30016

am_proc_good

User ,UID ,ProcessName

30017

am_low_memory

NumProcesses

Lru

30018

am_destroy_activity

User ,Token ,TaskID,ComponentName,Reason

30019

am_relaunch_resume_activity

User ,Token ,TaskID,ComponentName

30020

am_relaunch_activity

User ,Token ,TaskID,ComponentName

30021

am_on_paused_called

User ,ComponentName

30022

am_on_resume_called

User ,ComponentName

30023

am_kill

User ,PID ,ProcessName,OomAdj ,Reason

杀进程

30024

am_broadcast_discard_filter

User ,Broadcast ,Action,ReceiverNumber,BroadcastFilter

30025

am_broadcast_discard_app

User ,Broadcast ,Action,ReceiverNumber,App

30030

am_create_service

User ,ServiceRecord ,Name,UID ,PID

30031

am_destroy_service

User ,ServiceRecord ,PID

30032

am_process_crashed_too_much

User ,Name,PID

30033

am_drop_process

PID

30034

am_service_crashed_too_much

User ,Crash Count,ComponentName,PID

30035

am_schedule_service_restart

User ,ComponentName,Time

30036

am_provider_lost_process

User ,Package Name,UID ,Name

30037

am_process_start_timeout

User ,PID ,UID ,ProcessName

timeout

30039

am_crash

User ,PID ,ProcessName,Flags ,Exception,Message,File,Line

Crash

30040

am_wtf

User ,PID ,ProcessName,Flags ,Tag,Message

Wtf

30041

am_switch_user

id

30042

am_activity_fully_drawn_time

User ,Token ,ComponentName,time

30043

am_focused_activity

User ,ComponentName

30044

am_home_stack_moved

User ,To Front ,Top Stack Id ,Focused Stack Id ,Reason

30045

am_pre_boot

User ,Package

30046

am_meminfo

Cached,Free,Zram,Kernel,Native

内存

30047

am_pss

Pid, UID, ProcessName, Pss, Uss

进程

下面列举tag可能使用的部分场景：

am_low_memory：位于AMS.killAllBackgroundProcesses或者AMS.appDiedLocked，记录当前Lru进程队列长度。

am_pss：位于AMS.recordPssSampleLocked(

am_meminfo：位于AMS.dumpApplicationMemoryUsage

am_proc_start:位于AMS.startProcessLocked，启动进程

am_proc_bound:位于AMS.attachApplicationLocked

am_kill: 位于ProcessRecord.kill，杀掉进程

am_anr: 位于AMS.appNotResponding

am_crash:位于AMS.handleApplicationCrashInner

am_wtf:位于AMS.handleApplicationWtf

am_activity_launch_time：位于ActivityRecord.reportLaunchTimeLocked()，后面两个参数分别是thisTime和 totalTime.

am_activity_fully_drawn_time:位于ActivityRecord.reportFullyDrawnLocked, 后面两个参数分别是thisTime和 totalTime

am_broadcast_discard_filter:位于BroadcastQueue.logBroadcastReceiverDiscardLocked

am_broadcast_discard_app:位于BroadcastQueue.logBroadcastReceiverDiscardLocked

Activity生命周期相关的方法:

am_on_resume_called: 位于AT.performResumeActivity

am_on_paused_called: 位于AT.performPauseActivity, performDestroyActivity

am_resume_activity: 位于AS.resumeTopActivityInnerLocked

am_pause_activity: 位于AS.startPausingLocked

am_finish_activity: 位于AS.finishActivityLocked, removeHistoryRecordsForAppLocked

am_destroy_activity: 位于AS.destroyActivityLocked

am_focused_activity: 位于AMS.setFocusedActivityLocked, clearFocusedActivity

am_restart_activity: 位于ASS.realStartActivityLocked

am_create_activity: 位于ASS.startActivityUncheckedLocked

am_new_intent: 位于ASS.startActivityUncheckedLocked

am_task_to_front: 位于AS.moveTaskToFrontLocked

Window相关

wm_task_moved: 位于TaskStack.positionTask()

TaskId, toTop ? 1 : 0, position；

206，1，3，是指吧TaskId=206的移动到栈顶(即该栈的长度为4)

am_home_stack_moved: 位于ASS.moveHomeStack

CurrentUser, toFront ? 1:0 , homStackId, FocusedStackId

0,1,0,0, 是指userId=0, home栈顶的StackId=0, 当前focusedStackId=0,

2.2 Power

Num

TagName

格式

功能

2722

battery_level

level, voltage, temperature

2723

battery_status

status,health,present,plugged,technology

2730

battery_discharge

duration, minLevel,maxLevel

2724

power_sleep_requested

wakeLocksCleared

唤醒锁数量

2725

power_screen_broadcast_send

wakelockCount

2726

power_screen_broadcast_done

on, broadcastDuration, wakelockCount

2727

power_screen_broadcast_stop

which,wakelockCount

系统还没进入ready状态

2728

power_screen_state

offOrOn, becauseOfUser, totalTouchDownTime, touchCycles

2729

power_partial_wake_state

releasedorAcquired, tag

部分含义：

battery_level: [19,3660,352] //剩余电量19%, 电池电压3.66v, 电池温度35.2℃

power_screen_state: [0,3,0,0] // 灭屏状态(0), 屏幕超时(3). 当然还有其他设备管理策略(1),其他理由都为用户行为(2)

power_screen_state: [1,0,0,0] // 亮屏状态(1)

下面列举tag可能使用的部分场景：

power_sleep_requested: 位于PMS.goToSleepNoUpdateLocked

power_screen_state:位于Notifer.handleEarlyInteractiveChange, handleLateInteractiveChange

三. EventLog完整语义分析

在源码EventLogTags.java中,有大量类似的定义,那么括号中数字是什么含义呢? (以进程启动为例)

30014 am_proc_start (User|1|5),(PID|1|5),(UID|1|5),(Process Name|3),(Type|3),(Component|3)

am_proc_start之后紧跟着的几个括号，其中括号里的内容格式如下：

(|data type[|data unit])

(|数据类型[|数据单位])

那么(User|1|5) ==> 名字为User, 数据类型为1，数据单位为5，下面再来看看数据类型和数据单位：

3.1 数据类型

1: int

2: long

3: string

4: list

数据类型中int和string用得最多.

3.2 数据单位

1: Number of objects(对象个数)

2: Number of bytes(字节数)

3: Number of milliseconds(毫秒)

4: Number of allocations(分配个数)

5: Id

6: Percent(百分比)

3.3 实例解析

有了前面的准备知识，再来完整的看看如下语句：

am_proc_start (User|1|5),(PID|1|5),(UID|1|5),(Process Name|3),(Type|3),(Component|3) am_proc_start: [0,9227,10002,com.android.browser,content provider,com.android.browser/.provider.BrowserProvider2]

含义如下：

进程启动: UserId=0, pid=9227, uid=10002, ProcessName=com.android.browser, 数据类型=ContentProvider, 组件=com.android.browser/.provider.BrowserProvider2