基于Android 7.0的源碼分析

一.概述

前面介紹過AMS相關的一些數據結構，每個數據結構有大量的成員變量，為了查詢當前手機運行時狀態的 變化值，可以通過dumpsys activity命令來完成，該方法最終是調用AMS.dump()方法。

dumpsys命令用法簡要介紹過dumpsys命令 的基本用法，以及系統服務列表信息，那么本文重點介紹AMS。 根據dumpsys activity傳遞不同的參數， 對于AMS.dump便會輸出相應的對象信息。 具體可以跟哪些參數.

1.1 命令格式

dumpsys activity [options] [WHAT] 復制代碼

其中options為可選項，以-開頭， 主要有以下幾類：

options含義

-a	包括所有可用Server狀態
-c	包括Client狀態，即App端情況
-p PACKAGE	限定輸出指定包名

1.2 WHAT參數

列舉常見的WHAT參數：

序號WHAT解釋對應源碼

1	a[ctivities]	activity狀態	dumpActivitiesLocked()
2	b[roadcasts] [PACKAGE_NAME]	broadcast狀態	dumpBroadcastsLocked()
3	s[ervices] [COMP_SPEC …]	service狀態	newServiceDumperLocked().dumpLocked
4	prov[iders] [COMP_SPEC …]	content provider狀態	dumpProvidersLocked()
5	p[rocesses] [PACKAGE_NAME]	進程狀態	dumpProcessesLocked()
6	o[om]	內存管理	dumpOomLocked()
7	i[ntents] [PACKAGE_NAME]	pending intent狀態	dumpPendingIntentsLocked()
8	r[ecents]	最近activity	dumpRecentsLocked()
9	perm[issions]	URI授權情況	dumpPermissionsLocked()
10	all	所有activities信息	dumpActivity()
11	top	頂部activity信息	dumpActivity()
12	package	package相關信息	dump()

其中PACKAGE_NAME是指可跟包名，COMP_SPEC是指可跟具體組件信息，中括號是指縮寫字母；

二. dumpsys activity

前面介紹dumpsys activity根據后面跟著的不同參數則輸出相應的內容，當不跟任何參數， dumpsys activity等價于依次輸出下面8條命令：

dumpsys activity intents dumpsys activity broadcasts //廣播 dumpsys activity providers //provider dumpsys activity permissions dumpsys activity services //服務 dumpsys activity recents dumpsys activity activities //activity dumpsys activity processes 復制代碼

依次簡要說明這8條命令：

2.1 intents

//標志性開頭，dumpPendingIntentsLocked ACTIVITY MANAGER PENDING INTENTS (dumpsys activity intents) 復制代碼

輸出對象：

• PendingIntentRecord

2.2 broadcasts

//標志性開頭，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 broadcastsmHandler 復制代碼

主要輸出的對象：

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

2.3 provider

//標志性開頭，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: 復制代碼

主要輸出的對象：

• ProviderMap
• ContentProviderRecord， ContentProviderConnection

2.4 permissions

//標志性開頭，dumpPermissionsLocked ACTIVITY MANAGER URI PERMISSIONS (dumpsys activity permissions) 復制代碼

主要輸出的對象：

• UriPermission

2.5 Service

//標志性開頭，newServiceDumperLocked().dumpLocked ACTIVITY MANAGER SERVICES (dumpsys activity services) 復制代碼

主要輸出的對象：

• ActiveServices,
• ServiceRecord, ConnectionRecord,ProcessRecord

2.6 recents

//標志性開頭，dumpRecentsLocked ACTIVITY MANAGER RECENT TASKS (dumpsys activity recents) 復制代碼

主要輸出的對象：

• TaskRecord

2.7 activities

//標志性開頭，dumpActivitiesLocked ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)Display #0 (activities from top to bottom):Stack #0:Task id #[n]* Hist #[m]:Stack #1: 復制代碼

主要輸出的對象：

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

輸出格式樣例：

//{Hashcode #TaskId Affinity UserId 該task的Activity個數}； 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:進程名/uid} ProcessRecord{7c8a2af 12265:com.gityuan.demo/1000} 復制代碼

2.8 processes

//標志性開頭，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: 復制代碼

主要輸出的對象：

• AMS各種進程對象
• ProcessRecord, UidRecord

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

轉載于:https://juejin.im/post/5c067ed8f265da613b6f8bfa

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