基于Android 7.0的源码分析

一.概述

前面介绍过AMS相关的一些数据结构，每个数据结构有大量的成员变量，为了查询当前手机运行时状态的变化值，可以通过dumpsys activity命令来完成，该方法最终是调用AMS.dump()方法。

dumpsys命令用法简要介绍过dumpsys命令的基本用法，以及系统服务列表信息，那么本文重点介绍AMS。根据dumpsys activity传递不同的参数，对于AMS.dump便会输出相应的对象信息。具体可以跟哪些参数.

1.1 命令格式

dumpsys activity [options] [WHAT]

其中options为可选项，以-开头，主要有以下几类：

options	含义
-a	包括所有可用Server状态
-c	包括Client状态，即App端情况
-p PACKAGE	限定输出指定包名

1.2 WHAT参数

列举常见的WHAT参数：

序号	WHAT	解释	对应源码
1	a[ctivities]	activity状态	dumpActivitiesLocked()
2	b[roadcasts] [PACKAGE_NAME]	broadcast状态	dumpBroadcastsLocked()
3	s[ervices] [COMP_SPEC …]	service状态	newServiceDumperLocked().dumpLocked
4	prov[iders] [COMP_SPEC …]	content provider状态	dumpProvidersLocked()
5	p[rocesses] [PACKAGE_NAME]	进程状态	dumpProcessesLocked()
6	o[om]	内存管理	dumpOomLocked()
7	i[ntents] [PACKAGE_NAME]	pending intent状态	dumpPendingIntentsLocked()
8	r[ecents]	最近activity	dumpRecentsLocked()
9	perm[issions]	URI授权情况	dumpPermissionsLocked()
10	all	所有activities信息	dumpActivity()
11	top	顶部activity信息	dumpActivity()
12	package	package相关信息	dump()

其中PACKAGE_NAME是指可跟包名，COMP_SPEC是指可跟具体组件信息，中括号是指缩写字母；

二. dumpsys activity

前面介绍dumpsys activity根据后面跟着的不同参数则输出相应的内容，当不跟任何参数， dumpsys activity等价于依次输出下面8条命令：

dumpsys activity intents
dumpsys activity broadcasts //广播
dumpsys activity providers  //provider
dumpsys activity permissions
dumpsys activity services  //服务
dumpsys activity recents
dumpsys activity activities //activity
dumpsys activity processes

依次简要说明这8条命令：

2.1 intents

//标志性开头，dumpPendingIntentsLocked
ACTIVITY MANAGER PENDING INTENTS (dumpsys activity intents)

输出对象：

PendingIntentRecord

2.2 broadcasts

//标志性开头，dumpBroadcastsLocked
ACTIVITY MANAGER BROADCAST STATE (dumpsys activity broadcasts)
    Registered Receivers：
    Receiver Resolver Table：
    Historical broadcasts [foreground]:
    Historical broadcasts summary [foreground]:
    Historical broadcasts [background]:
    Historical broadcasts summary [background]:
    Sticky broadcasts
    mHandler

主要输出的对象：

ReceiverList, BroadcastFilter,
IntentResolver,
BroadcastQueue, BroadcastRecord
Handler, Looper

2.3 provider

//标志性开头，dumpProvidersLocked
ACTIVITY MANAGER CONTENT PROVIDERS (dumpsys activity providers)
    Published single-user content providers (by class):
    Published user [n] content providers (by class):
    Single-user authority to provider mappings:
    User [n] authority to provider mappings:

主要输出的对象：

ProviderMap
ContentProviderRecord， ContentProviderConnection

2.4 permissions

//标志性开头，dumpPermissionsLocked
ACTIVITY MANAGER URI PERMISSIONS (dumpsys activity permissions)

主要输出的对象：

UriPermission

2.5 Service

//标志性开头，newServiceDumperLocked().dumpLocked
ACTIVITY MANAGER SERVICES (dumpsys activity services)

主要输出的对象：

ActiveServices,
ServiceRecord, ConnectionRecord,ProcessRecord

2.6 recents

//标志性开头，dumpRecentsLocked
ACTIVITY MANAGER RECENT TASKS (dumpsys activity recents)

主要输出的对象：

TaskRecord

2.7 activities

//标志性开头，dumpActivitiesLocked
ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
    Display #0 (activities from top to bottom):
      Stack #0:
        Task id #[n]
          * Hist #[m]:
      Stack #1:

主要输出的对象：

ActivityStackSupervisor, ActivityStack,
TaskRecord, ActivityRecord
ActivityThread, Activity
ViewRootImpl
Looper, MessageQueue

输出格式样例：

//{Hashcode #TaskId Affinity UserId 该task的Activity个数}；
TaskRecord{e6d7a8e #156 A=com.gityuan.demo U=0 sz=1}
userId=0 effectiveUid=1000 mCallingUid=1000 mCallingPackage=android
realActivity=com.gityuan.demo/.Blog

//ProcessRecord{Hashcode pid:进程名/uid}
ProcessRecord{7c8a2af 12265:com.gityuan.demo/1000}

2.8 processes

//标志性开头，dumpProcessesLocked
ACTIVITY MANAGER RUNNING PROCESSES (dumpsys activity processes)
    All known processes:
    Isolated process list (sorted by uid):
    UID states:
    UID validation:
    Process LRU list (sorted by oom_adj, 60 total, non-act at 2, non-svc at 2):
    PID mappings:
    Foreground Processes:

主要输出的对象：

AMS各种进程对象
ProcessRecord, UidRecord

转载：http://gityuan.com/2017/07/04/ams_dumpsys/