## 1. 基本概念 ### 1.1?Instrumentation是什么? 顧名思義，儀器儀表，用于在應用程序中進行“測量”和“管理”工作。一個應用程序中只有一個Instrumentation實例對象，且每個Activity都有此對象的引用。Instrumentation將在任何應用程序運行前初始化，可以通過它監測系統與應用程序之間的所有交互，即類似于在系統與應用程序之間安裝了個“竊聽器”。 ? ? ? 當ActivityThread 創建(callActivityOnCreate)、暫停、恢復某個Activity時，通過調用此對象的方法來實現，如： ? ? ? ? ?1)?創建:?callActivityOnCreate? ? ? ? ? ?2)?暫停:?callActivityOnPause ? ? ? ? ?3)?恢復:?callActivityOnResume Instrumentation和ActivityThread的關系，類似于老板與經理的關系，老板負責對外交流(如與Activity Manager Service<AMS>)，Instrumentation負責管理并完成老板交待的任務。 它通過以下兩個成員變量來對當前應用進程中的Activity進行管理： ~~~ private?List<ActivityWaiter>?mWaitingActivities;?? private?List<ActivityMonitor>?mActivityMonitors;?? ~~~ 其功能函數下表所示： <table border="1" cellspacing="1" cellpadding="1" style="color:rgb(51,51,51); font-family:Arial; font-size:14px; line-height:26px"><tbody><tr><td><span style="font-size:18px">功能</span></td><td><span style="font-size:18px">函數</span></td></tr><tr><td><span style="font-size:18px">增加刪除Monitor</span></td><td><span style="font-size:18px">addMonitor(ActivityMonitor monitor)<br/>removeMonitor(ActivityMonitor monitor)</span></td></tr><tr><td><span style="font-size:18px">Application與Activity生命周期控制</span></td><td><span style="font-size:18px">newApplication(Class&lt;?&gt; clazz, Context context)<br/>newActivity(ClassLoader cl, String className,Intent intent)<br/>callActivityOnCreate(Activity activity, Bundle icicle)<br/>callActivityOnDestroy(Activity activity)<br/>callActivityOnStart(Activity activity)<br/>callActivityOnRestart(Activity activity)<br/>callActivityOnResume(Activity activity)<br/>callActivityOnStop(Activity activity)<br/>callActivityOnPause(Activity activity)<br/></span></td></tr><tr><td><span style="font-size:18px">Instrumentation生命周期控制</span></td><td><span style="font-size:18px">onCreate(Bundle arguments)<br/>start()<br/>onStart()<br/>finish(int resultCode, Bundle results)<br/>onDestroy()<br/></span></td></tr><tr><td><span style="font-size:18px">發送用戶操控信息到當前窗口</span></td><td><span style="font-size:18px">sendCharacterSync(int keyCode)<br/>sendPointerSync(MotionEvent event)<br/>sendTrackballEventSync(MotionEvent event)<br/>sendTrackballEventSync(MotionEvent event)<br/></span></td></tr><tr><td><span style="font-size:18px">同步操作</span></td><td><span style="font-size:18px">startActivitySync(Intent intent) //它調用Context.startActivity<br/>runOnMainSync(Runnable runner)<br/>waitForIdle()<br/></span></td></tr></tbody></table> ## 2.?Android應用程序啟動過程(MainActivity) 即MainActivity的啟動過程，在此過程中，將創建一個新的進程來執行此MainActivity。 Android應用程序從Launcher啟動流程如下所示： ~~~ /*****************************************************************? ?*?Launcher通過Binder告訴ActivityManagerService，? ?*?它將要啟動一個新的Activity；? ?****************************************************************/?? Launcher.startActivitySafely->???? Launcher.startActivity->???? ?//要求在新的Task中啟動此Activity???? ?//intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)???? ?Activity.startActivity->???? ?Activity.startActivityForResult->???? ?Instrumentation.execStartActivity->???? ??//?ActivityManagerNative.getDefault()返回AMS?Proxy接口???? ??ActivityManagerNative.getDefault().startActivity->???? ??ActivityManagerProxy.startActivity->???? ???? ???ActivityManagerService.startActivity->?(AMS)???? ???ActivityManagerService.startActivityAsUser->????? ???? ????ActivityStack.startActivityMayWait->???? ????ActivityStack.resolveActivity(獲取ActivityInfo)???? ??????//aInfo.name為main?Activity,如：com.my.test.MainActivity???? ??????//aInfo.applicationInfo.packageName為包名，如com.my.test???? ????ActivityStack.startActivityLocked->???? ??????//ProcessRecord?callerApp;?調用者即Launcher信息???? ??????//ActivityRecord?sourceRecord;?Launcher?Activity相關信息???? ??????//ActivityRecord?r=new?ActivityRecord(...)，將要創建的Activity相關信息?????? ????ActivityStack.startActivityUncheckedLocked->???? ?????//Activity啟動方式：ActivityInfo.LAUNCH_MULTIPLE/LAUNCH_SINGLE_INSTANCE/???? ?????//?????????????ActivityInfo.LAUNCH_SINGLE_TASK/LAUNCH_SINGLE_TOP)???? ?????//?創建一個新的task,即TaskRecord,并保存在ActivityRecord.task中???? ?????//r.setTask(new?TaskRecord(mService.mCurTask,?r.info,?intent),?null,?true)???? ?????//?把新創建的Activity放在棧頂??????? ?????ActivityStack.startActivityLocked->???? ?????ActivityStack.resumeTopActivityLocked->???? ?????ActivityStack.startPausingLocked?(使Launcher進入Paused狀態)->?????? ?? ?????/*****************************************************************? ??????*?AMS通過Binder通知Launcher進入Paused狀態? ??????****************************************************************/?? ??????ApplicationThreadProxy.schedulePauseActivity->????? ??????//private?class?ApplicationThread?extends?ApplicationThreadNative???? ??????ApplicationThread.schedulePauseActivity->???? ???? ???????ActivityThread.queueOrSendMessage->???? ????? ???????//?調用Activity.onUserLeaveHint???? ???????//?調用Activity.onPause???? ???????//?通知activity?manager我進入了pause狀態???? ???????ActivityThread.handlePauseActivity->???? ?? ???????/*****************************************************************? ????????*?Launcher通過Binder告訴AMS，它已經進入Paused狀態? ????????****************************************************************/?? ???????ActivityManagerProxy.activityPaused->???? ???????ActivityManagerService.activityPaused->???? ???????ActivityStack.activityPaused->(把Activity狀態修改為PAUSED)???? ???????ActivityStack.completePauseLocked->???? ?????? ???????//?參數為代表Launcher這個Activity的ActivityRecord???? ???????//?使用棧頂的Activity進入RESUME狀態???? ???????ActivityStack.resumeTopActivityLokced->???? ?????????//topRunningActivityLocked將剛創建的放于棧頂的activity取回來???? ?????????//?即在ActivityStack.startActivityUncheckedLocked中創建的???? ?? ???????/*****************************************************************? ????????*?AMS創建一個新的進程，用來啟動一個ActivityThread實例，? ????????*?即將要啟動的Activity就是在這個ActivityThread實例中運行? ????????****************************************************************/?? ???????ActivityStack.startSpecificActivityLocked->???? ???? ????????//?創建對應的ProcessRecord???? ????????ActivityManagerService.startProcessLocked->???? ???????????? ?????????//?啟動一個新的進程???? ?????????//?新的進程會導入android.app.ActivityThread類，并且執行它的main函數,???? ?????????//?即實例化ActivityThread,?每個應用有且僅有一個ActivityThread實例???? ?????????Process.start("android.app.ActivityThread",...)->???? ?? ?????????//?通過zygote機制創建一個新的進程???? ?????????Process.startViaZygote->???? ?????? ?????????//?這個函數在進程中創建一個ActivityThread實例，然后調用???? ?????????//?它的attach函數，接著就進入消息循環???? ?????????ActivityThread.main->???? ?? ?????????/*****************************************************************? ??????????*?ActivityThread通過Binder將一個ApplicationThread類的Binder對象? ??????????*?傳遞給AMS，以便AMS通過此Binder對象來控制Activity整個生命周期? ??????????****************************************************************/?? ?????????ActivityThread.attach->???? ?????????IActivityManager.attachApplication(mAppThread)->???? ?????????ActivityManagerProxy.attachApplication->???? ?????????ActivityManagerService.attachApplication->???? ???? ?????????//?把在ActivityManagerService.startProcessLocked中創建的ProcessRecord取出來???? ?????????ActivityManagerService.attachApplicationLocked->???? ?? ?????????/*****************************************************************? ??????????*?AMS通過Binder通知ActivityThread一切準備OK,它可以真正啟動新的Activity了? ??????????****************************************************************/?????????????? ?????????//?真正啟動Activity???? ?????????ActivityStack.realStartActivityLocked->???? ?????????ApplicationThreadProxy.scheduleLaunchActivity->???? ?????????ApplicationThread.scheduleLaunchActivity->???? ?????????ActivityThread.handleLaunchActivity->???? ???????????//?加載新的Activity類，并執行它的onCreate???? ???????????ActivityThread.performLaunchActivity???? ????????????/*1)?Instrumentation.newActivity:?加載新類，即創建Activity對象；?? ??????????????2)?ActivityClientRecord.packageInfo.makeApplication：創建Application對象；?? ?????????????????<LoadedApk.makeApplication>?? ??????????????3)?Activity.attach(Context?context,?ActivityThread?aThread,?? ????????????????????Instrumentation?instr,?IBinder?token,?int?ident,?? ????????????????????Application?application,?Intent?intent,?ActivityInfo?info,?? ????????????????????CharSequence?title,?Activity?parent,?String?id,?? ????????????????????NonConfigurationInstances?lastNonConfigurationInstances,?? ????????????????????Configuration?config)：把Application?attach到Activity,?即把Activtiy?? ???????????????????????????????????????????相關信息設置到新創建的Activity中?? ??????????????4)?Instrumentation.callActivityOnCreate：調用onCreate；*/???? ?????? ???????????//?使用Activity進入RESUMED狀態，并調用onResume???? ???????????ActivityThread.handleResumeActivity???? ~~~ ## 3. ActivityManagerService ### 3.1 類中關鍵信息 ~~~ public?final?class?ActivityManagerService?extends?ActivityManagerNative?? ????????implements?Watchdog.Monitor,?BatteryStatsImpl.BatteryCallback?{?? ????...?? ????//?Maximum?number?of?recent?tasks?that?we?can?remember.?? ????static?final?int?MAX_RECENT_TASKS?=?20;?? ?? ????public?ActivityStack?mMainStack;?//?管理Activity堆棧?? ?? ????//?Whether?we?should?show?our?dialogs?(ANR,?crash,?etc)?or?just?perform?their?? ????//?default?actuion?automatically.??Important?for?devices?without?direct?input?? ????//?devices.?? ????private?boolean?mShowDialogs?=?true;?? ?? ????/**? ?????*?Description?of?a?request?to?start?a?new?activity,?which?has?been?held? ?????*?due?to?app?switches?being?disabled.? ?????*/?? ????static?class?PendingActivityLaunch?{?? ????????ActivityRecord?r;?? ????????ActivityRecord?sourceRecord;?? ????????int?startFlags;?? ????}?? ?? ?? ????/**? ?????*?Activity?we?have?told?the?window?manager?to?have?key?focus.? ?????*/?? ????ActivityRecord?mFocusedActivity?=?null;?? ?? ????/**? ?????*?List?of?intents?that?were?used?to?start?the?most?recent?tasks.? ?????*/?? ????final?ArrayList<TaskRecord>?mRecentTasks?=?new?ArrayList<TaskRecord>();?? ?? ????/**? ?????*?Process?management.? ?????*/?? ????final?ProcessList?mProcessList?=?new?ProcessList();?? ?? ????/**? ?????*?All?of?the?applications?we?currently?have?running?organized?by?name.? ?????*?The?keys?are?strings?of?the?application?package?name?(as? ?????*?returned?by?the?package?manager),?and?the?keys?are?ApplicationRecord? ?????*?objects.? ?????*/?? ????final?ProcessMap<ProcessRecord>?mProcessNames?=?new?ProcessMap<ProcessRecord>();?? ?? ????/**? ?????*?The?currently?running?isolated?processes.? ?????*/?? ????final?SparseArray<ProcessRecord>?mIsolatedProcesses?=?new?SparseArray<ProcessRecord>();?? ????...?? ?? ????public?static?final?Context?main(int?factoryTest)?{?//main入口函數?? ????????AThread?thr?=?new?AThread();?? ????????thr.start();?? ?? ????????synchronized?(thr)?{?? ????????????while?(thr.mService?==?null)?{?? ????????????????try?{?? ????????????????????thr.wait();?? ????????????????}?catch?(InterruptedException?e)?{?? ????????????????}?? ????????????}?? ????????}?? ?? ????????ActivityManagerService?m?=?thr.mService;?? ????????mSelf?=?m;?? ????????ActivityThread?at?=?ActivityThread.systemMain();?? ????????mSystemThread?=?at;?? ????????Context?context?=?at.getSystemContext();?? ????????context.setTheme(android.R.style.Theme_Holo);?? ????????m.mContext?=?context;?? ????????m.mFactoryTest?=?factoryTest;?? ????????m.mMainStack?=?new?ActivityStack(m,?context,?true);?//?創建ActivityStack?? ?????????? ????????m.mBatteryStatsService.publish(context);?? ????????m.mUsageStatsService.publish(context);?? ?????????? ????????synchronized?(thr)?{?? ????????????thr.mReady?=?true;?? ????????????thr.notifyAll();?? ????????}?? ?? ????????m.startRunning(null,?null,?null,?null);?? ?????????? ????????return?context;?? ????}?? }?? ~~~ ### 3.2 家族圖譜  ## 4. ActivityStack-真正做事的家伙 ActivityManagerService使用它來管理系統中所有的Activities的狀態，Activities使用stack的方式進行管理。它是真正負責做事的家伙，很勤快的，但外界無人知道！ ### 4.1 類中關鍵信息 ? ? ~~~ /**? ?*?State?and?management?of?a?single?stack?of?activities.? ?*/?? final?class?ActivityStack?{?? ????final?ActivityManagerService?mService;?? ????final?boolean?mMainStack;?? ????final?Context?mContext;?? ?? ????enum?ActivityState?{?? ????????INITIALIZING,?? ????????RESUMED,?? ????????PAUSING,?? ????????PAUSED,?? ????????STOPPING,?? ????????STOPPED,?? ????????FINISHING,?? ????????DESTROYING,?? ????????DESTROYED?? ????}?? ?? ????/**? ?????*?The?back?history?of?all?previous?(and?possibly?still? ?????*?running)?activities.??It?contains?HistoryRecord?objects.? ?????*/?? ????final?ArrayList<ActivityRecord>?mHistory?=?new?ArrayList<ActivityRecord>();?? ?? ????/**? ?????*?Used?for?validating?app?tokens?with?window?manager.? ?????*/?? ????final?ArrayList<IBinder>?mValidateAppTokens?=?new?ArrayList<IBinder>();?? ?? ????/**? ?????*?List?of?running?activities,?sorted?by?recent?usage.? ?????*?The?first?entry?in?the?list?is?the?least?recently?used.? ?????*?It?contains?HistoryRecord?objects.? ?????*/?? ????final?ArrayList<ActivityRecord>?mLRUActivities?=?new?ArrayList<ActivityRecord>();?? ?? ????/**? ?????*?List?of?activities?that?are?waiting?for?a?new?activity? ?????*?to?become?visible?before?completing?whatever?operation?they?are? ?????*?supposed?to?do.? ?????*/?? ????final?ArrayList<ActivityRecord>?mWaitingVisibleActivities?? ????????????=?new?ArrayList<ActivityRecord>();?? ?? ????/**? ?????*?List?of?activities?that?are?ready?to?be?stopped,?but?waiting? ?????*?for?the?next?activity?to?settle?down?before?doing?so.??It?contains? ?????*?HistoryRecord?objects.? ?????*/?? ????final?ArrayList<ActivityRecord>?mStoppingActivities?? ????????????=?new?ArrayList<ActivityRecord>();?? ?? ????/**? ?????*?List?of?activities?that?are?in?the?process?of?going?to?sleep.? ?????*/?? ????final?ArrayList<ActivityRecord>?mGoingToSleepActivities?? ????????????=?new?ArrayList<ActivityRecord>();?? ????/**? ?????*?When?we?are?in?the?process?of?pausing?an?activity,?before?starting?the? ?????*?next?one,?this?variable?holds?the?activity?that?is?currently?being?paused.? ?????*/?? ????ActivityRecord?mPausingActivity?=?null;?? ?? ????/**? ?????*?This?is?the?last?activity?that?we?put?into?the?paused?state.??This?is? ?????*?used?to?determine?if?we?need?to?do?an?activity?transition?while?sleeping,? ?????*?when?we?normally?hold?the?top?activity?paused.? ?????*/?? ????ActivityRecord?mLastPausedActivity?=?null;?? ?? ????/**? ?????*?Current?activity?that?is?resumed,?or?null?if?there?is?none.? ?????*/?? ????ActivityRecord?mResumedActivity?=?null;?? ?????? ????/**? ?????*?This?is?the?last?activity?that?has?been?started.??It?is?only?used?to? ?????*?identify?when?multiple?activities?are?started?at?once?so?that?the?user? ?????*?can?be?warned?they?may?not?be?in?the?activity?they?think?they?are.? ?????*/?? ????ActivityRecord?mLastStartedActivity?=?null;?? ?? ????/**? ?????*?Set?to?indicate?whether?to?issue?an?onUserLeaving?callback?when?a? ?????*?newly?launched?activity?is?being?brought?in?front?of?us.? ?????*/?? ????boolean?mUserLeaving?=?false;?? ?? ????ActivityStack(ActivityManagerService?service,?Context?context,?boolean?mainStack)?{?? ????????mService?=?service;?? ????????mContext?=?context;?? ????????mMainStack?=?mainStack;?? ????????...?? ????}?? ????...?? }?? ~~~ ### 4.2 家族圖譜  ## 5. ProcessRecord 記錄了一個進程的相關信息。 ### 5.1 類中關鍵信息 ~~~ /**? ?*?Full?information?about?a?particular?process?that? ?*?is?currently?running.? ?*/?? class?ProcessRecord?{?? ????final?ApplicationInfo?info;?//?all?about?the?first?app?in?the?process?? ????final?boolean?isolated;?????//?true?if?this?is?a?special?isolated?process?? ????final?int?uid;??????????????//?uid?of?process;?may?be?different?from?'info'?if?isolated?? ????final?int?userId;???????????//?user?of?process.?? ????final?String?processName;???//?name?of?the?process?? ?? ????IApplicationThread?thread;??//?the?actual?proc...??may?be?null?only?if?? ????????????????????????????????//?'persistent'?is?true?(in?which?case?we?? ????????????????????????????????//?are?in?the?process?of?launching?the?app)?? ????????????????????????????????//?是ApplicationThread對象的遠程接口,?? ????????????????????????????????//?通過此接口通知Activity進入對應的狀態?? ?????????????????????????????????? ????int?pid;????????????????????//?The?process?of?this?application;?0?if?none?? ????ApplicationInfo?instrumentationInfo;?//?the?application?being?instrumented?? ?? ????BroadcastRecord?curReceiver;//?receiver?currently?running?in?the?app?? ?? ????//?contains?HistoryRecord?objects?? ????final?ArrayList<ActivityRecord>?activities?=?new?ArrayList<ActivityRecord>();?? ?? ????//?all?ServiceRecord?running?in?this?process?? ????final?HashSet<ServiceRecord>?services?=?new?HashSet<ServiceRecord>();?? ?? ????//?services?that?are?currently?executing?code?(need?to?remain?foreground).?? ????final?HashSet<ServiceRecord>?executingServices?? ?????????????=?new?HashSet<ServiceRecord>();?? ?? ????//?All?ConnectionRecord?this?process?holds?? ????final?HashSet<ConnectionRecord>?connections?? ????????????=?new?HashSet<ConnectionRecord>();???? ?? ????//?all?IIntentReceivers?that?are?registered?from?this?process.?? ????final?HashSet<ReceiverList>?receivers?=?new?HashSet<ReceiverList>();?? ?? ????//?class?(String)?->?ContentProviderRecord?? ????final?HashMap<String,?ContentProviderRecord>?pubProviders?? ????????????=?new?HashMap<String,?ContentProviderRecord>();??? ?? ????//?All?ContentProviderRecord?process?is?using?? ????final?ArrayList<ContentProviderConnection>?conProviders?? ????????????=?new?ArrayList<ContentProviderConnection>();?? ?????? ????boolean?persistent;?????????//?always?keep?this?application?running??? ????boolean?crashing;???????????//?are?we?in?the?process?of?crashing??? ????Dialog?crashDialog;?????????//?dialog?being?displayed?due?to?crash.?? ????boolean?notResponding;??????//?does?the?app?have?a?not?responding?dialog??? ????Dialog?anrDialog;???????????//?dialog?being?displayed?due?to?app?not?resp.?? ????boolean?removed;????????????//?has?app?package?been?removed?from?device??? ????boolean?debugging;??????????//?was?app?launched?for?debugging??? ????boolean?waitedForDebugger;??//?has?process?show?wait?for?debugger?dialog??? ????Dialog?waitDialog;??????????//?current?wait?for?debugger?dialog?? ?? ????ProcessRecord(BatteryStatsImpl.Uid.Proc?_batteryStats,?IApplicationThread?_thread,?? ????????????ApplicationInfo?_info,?String?_processName,?int?_uid)?{?? ????????batteryStats?=?_batteryStats;?? ????????info?=?_info;?? ????????isolated?=?_info.uid?!=?_uid;?? ????????uid?=?_uid;?? ????????userId?=?UserHandle.getUserId(_uid);?? ????????processName?=?_processName;?? ????????pkgList.add(_info.packageName);?? ????????thread?=?_thread;?? ????????maxAdj?=?ProcessList.HIDDEN_APP_MAX_ADJ;?? ????????hiddenAdj?=?clientHiddenAdj?=?emptyAdj?=?ProcessList.HIDDEN_APP_MIN_ADJ;?? ????????curRawAdj?=?setRawAdj?=?-100;?? ????????curAdj?=?setAdj?=?-100;?? ????????persistent?=?false;?? ????????removed?=?false;?? ????}?? ????...?? }?? ~~~ ### 5. 2 家族圖譜  ## 6. IApplicationThread接口AMS->Application IApplicationThread為AMS作為客戶端訪問Application服務器端的Binder接口。當創建Application時，將把此Binder對象傳遞給AMS，然后AMS把它保存在mProcessNames.ProcessRecord.thread中。當需要通知Application工作時，則調用IApplicationThread中對應的接口函數。 其相互關系如下圖所示：