??Activity啟動流程(三)- Activity Task調度演算法復盤分析
Android四大組件原始碼實作詳解系列博客目錄:
Android應用行程創建流程大揭秘
Android四大組件之bindService原始碼實作詳解
Android四大組件之Activity啟動流程原始碼實作詳解概要
Android四大組件之Activity啟動流程原始碼實作詳解(一)
Android四大組件之Activity啟動流程原始碼實作詳解(二)
Activity啟動流程(三)- Activity Task調度演算法復盤分析
前言
??還記得我們在前面博客Android四大組件之Activity啟動流程原始碼實作詳解(二)中做的艱苦卓越的斗爭嗎！這場戰役之慘烈，戰況之持久前所未有！雖然程序是疼苦的，但是戰果也是顯赫和令人滿意的，通過上述戰役我們取得了如下的階段性成果：
- 初始化了Activity啟動狀態
- 計算了啟動launchFlag
- 計算了呼叫者的ActivityStack
- 檢查了是否存在復用的TaskRecord
- 對于存在復用的TaskRecord則進行相應的ActivityStack、TaskRecord的移動（說實話，我也沒有真的搞懂，希望這塊比較有經驗的小伙們能和我一起學習）
- 計算了當前啟動Activity所屬的TaskRecord
- 把當前啟動的Activity放到所屬TaskRecord的堆疊頂
- 并且前面的TaskRecord放到了ActivityStack的堆疊頂
總而言之經過上述一頓猛虎般的操作，此時要啟動的目標Actvity及其對應的task位置以及ActivityStack已經安排妥當，現在可以準備接下來的相關作業了,本來我也是準備這么干的，可是總感覺分析少了點什么！通過前面的分析我們知道了ActivityStack類的startActivityUncheckedLocked方法負責調度ActivityRecord以及TaskRecord，并且通過前面的分析我們也可以知道調度演算法非常復雜，最好需結合實際場景分析調度演算法，但是前面我們只是對startActivityUncheckedLocked整個原始碼進行了流水式的分析，而沒有結合實際，所以本篇博客將結合實際場景分析調度演算法，將Activity啟動程序中涉及的TaskRecord和ActivityStack的調度再來復盤一下！
注意：本篇的介紹是基于Android 7.xx平臺為基礎的，其中涉及的代碼路徑如下：
frameworks/base/services/core/java/com/android/server/am/
--- ActivityManagerService.java
--- ProcessRecord.java
--- ActivityRecord.java
--- ActivityResult.java
--- ActivityStack.java
--- ActivityStackSupervisor.java
--- ActivityStarter.java
--- TaskRecord.java
frameworks/base/services/core/java/com/android/server/pm/
--- PackageManagerService.java
frameworks/base/core/java/android/content/pm/
--- ActivityInfo.java
frameworks/base/core/java/android/app/
--- IActivityManager.java
--- ActivityManagerNative.java (內部包含AMP)
--- ActivityManager.java
--- AppGlobals.java
--- Activity.java
--- ActivityThread.java(內含AT)
--- LoadedApk.java
--- AppGlobals.java
--- Application.java
--- Instrumentation.java
--- IApplicationThread.java
--- ApplicationThreadNative.java (內部包含ATP)
--- ActivityThread.java (內含ApplicationThread)
--- ContextImpl.java
并且在后續的原始碼分析程序中為了簡述方便，會將做如下簡述:
- ApplicationThreadProxy簡稱為ATP
- ActivityManagerProxy簡稱為AMP
- ActivityManagerService簡稱為AMS
- ActivityManagerNative簡稱AMN
- ApplicationThreadNative簡稱ATN
- PackageManagerService簡稱為PKMS
- ApplicationThread簡稱為AT
- ActivityStarter簡稱為AS,這里不要和ActivityServices搞混淆了
- ActivityStackSupervisor簡稱為ASS
在正式開始今天博客相關原始碼分析前，還是先奉上呼叫的時序圖以便小伙們先從整體上有個清晰的概括，然后再從細節開擼！
一.實際場景一復盤分析
??假設我們存在如下的Activity啟動場景某應用內有兩個Activity,A和B,A為該應用入口Activity，從A可跳轉至B，A和B的啟動模式都為standard，我們以該場景為切入口來分析Activity啟動程序中Task任務堆疊和Activity堆疊的調度，本章接將會重點圍繞如下三種Activity啟動情況分析：
-
從Launcher桌面第一次啟動應用時的任務調度情況:
-
任務調度時會創建新task，并將新的ActivityRecord加入這個新的task，然后將task放入合適的Stack的堆疊頂
-
應用內Activity跳轉時的任務調度情況:
-
任務調度時會將新的ActivityRecord加入已有的task，然后將該ActivityRecord移動到Task頂端，然后將task放入合適的Stack的堆疊頂
-
然后按Home鍵，再打開應用程式時的調度情況:
-
任務調度時會先找到已有的相關task，并顯示堆疊頂的Activity
通過前面的博客Android四大組件之Activity啟動流程原始碼實作詳解(二)我們知道Activity啟動程序中Task和ActivityStack的調度涉及的代碼眾多，所以在復盤的程序中我們只抽取重點，并將AS.startActivityUnchecked中的涉及的方法，我們將采用偽代碼的方式進行分析，只為了小伙們們能更好的了解Task和ActivityStack的調度！
1.1 從Launcher桌面第一次啟動應用時Activity的Task以及Stack調度情況
??在正式啟動前，我們先來看看此時Android終端中的各種Task和ActivityStack的情況，我們可以通過Android內置的命令dumpsys activity activities來進行查看，此時的Activity的堆疊以及Task情況如下：
#adb shell dumpsys activity activities
ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
Display #0 (activities from top to bottom):
Stack #0://Home所屬Stack對應的taskid，其對應的值為HOME_STACK_ID
mFullscreen=true
mBounds=null
Task id #8
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
userId=0 effectiveUid=u0a23 mCallingUid=0 mUserSetupComplete=true mCallingPackage=null
affinity=com.android.launcher3
intent={act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher}
realActivity=com.android.launcher3/.Launcher
autoRemoveRecents=false isPersistable=true numFullscreen=1 taskType=1 mTaskToReturnTo=1
rootWasReset=false mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=null lastThumbnailFile=/data/system_ce/0/recent_images/8_task_thumbnail.png
stackId=0
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=false firstActiveTime=1602505452631 lastActiveTime=1602505452631 (inactive for 2s)
* Hist #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
packageName=com.android.launcher3 processName=com.android.launcher3
launchedFromUid=0 launchedFromPackage=null userId=0
app=ProcessRecord{c4940bc 14811:com.android.launcher3/u0a23}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher }
frontOfTask=true task=TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
taskAffinity=com.android.launcher3
realActivity=com.android.launcher3/.Launcher
baseDir=/system/app/PaxLauncher3/PaxLauncher3.apk
dataDir=/data/user/0/com.android.launcher3
stateNotNeeded=true componentSpecified=false mActivityType=1
compat={320dpi} labelRes=0x7f0a0001 icon=0x7f030001 theme=0x7f0d0002
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ff222222
launchFailed=false launchCount=0 lastLaunchTime=-1m17s726ms
haveState=false icicle=null
state=RESUMED stopped=false delayedResume=false finishing=false
keysPaused=false inHistory=true visible=true sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_NOT_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=2
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=HOME_ACTIVITY_TYPE
waitingVisible=false nowVisible=true lastVisibleTime=-2s190ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
Run #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mResumedActivity: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mLastPausedActivity: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mFocusedActivity: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mFocusedStack=ActivityStack{a520845 stackId=0, 1 tasks} mLastFocusedStack=ActivityStack{a520845 stackId=0, 1 tasks}
mSleepTimeout=false
mCurTaskIdForUser={0=8}
mUserStackInFront={}
mActivityContainers={0=ActivtyContainer{0}A}
mLockTaskModeState=NONE mLockTaskPackages (userId:packages)=
0:[]
mLockTaskModeTasks[]
通過前面的dump，此時我們可以知道了ASS中的mHomeStack已經創建了，并且Launcher桌面Activity對應的Task和ActivityRecord都已經OK了！但是由于Launcher桌面Activity的啟動不在本篇的分析中，它對應的Activity的Task以及相關的調度就不予分析了！
從Launcher桌面第一次啟動應用時Activity的Task以及Stack調度執行如下所示:
//[ActivityStarter.java]
/*
這里的sourceRecord是指發起呼叫者
r是指本次的將要啟動的Activity
startFlags取值為0
doResume的值為true
inTask為發起方指定的任務堆疊，此時為null
這里主要確定目標Activity的launchMode Task堆疊等,即Task的創建和管理
*/
private int startActivityUnchecked(final ActivityRecord r,
ActivityRecord sourceRecord,
IVoiceInteractionSession voiceSession,
IVoiceInteractor voiceInteractor,
int startFlags,
boolean doResume,
ActivityOptions options,
TaskRecord inTask) {
//設定初始化狀態，此時需要重點關注該方法中的如下幾個目標值的獲取，為了分析的方便，我會將該方法展開
setInitialState(r, options, inTask, doResume, startFlags, sourceRecord, voiceSession,
voiceInteractor);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private void setInitialState(ActivityRecord r,
ActivityOptions options,
TaskRecord inTask,
boolean doResume,
int startFlags,
ActivityRecord sourceRecord,
IVoiceInteractionSession
voiceSession,
IVoiceInteractor voiceInteractor) {
//此處分支會走，將啟動程序中的涉及的相關變數進行初始化
reset();
...
mLaunchSingleTop = r.launchMode == LAUNCH_SINGLE_TOP;//此時為false
mLaunchSingleInstance = r.launchMode == LAUNCH_SINGLE_INSTANCE;//此時為false
mLaunchSingleTask = r.launchMode == LAUNCH_SINGLE_TASK;//此時為false
//這里重點關注一下，此時mIntent.getFlags攜帶的為FLAG_ACTIVITY_RESET_TASK_IF_NEEDED|FLAG_ACTIVITY_NEW_TASK,這個地方是關鍵因為后面會根據這些值進行Task和Stack的調度
mLaunchFlags = adjustLaunchFlagsToDocumentMode(r,mLaunchSingleInstance, mLaunchSingleTask, mIntent.getFlags());
...
mDoResume = doResume;
...
mInTask = inTask;
...
mStartFlags = startFlags;//此時的mStartFlags為0
}
/*****************************************************************************/
//根據發起端，計算目標Activity的launchMode模式
computeLaunchingTaskFlags();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//根據發起者launchMode情況，決定目標Activity的Flags情況
private void computeLaunchingTaskFlags() {
//此時場景下的mSourceRecord不為null，mInTask為null，所以不會進入該分支
if (mSourceRecord == null && mInTask != null && mInTask.stack != null) {
...
}else {//會進入此分支
mInTask = null;
//不滿足條件，不會進入該分支
if ((mStartActivity.isResolverActivity() || mStartActivity.noDisplay) && mSourceRecord != null
&& mSourceRecord.isFreeform()) {
...
}
}
}
//此時的mInTask為null，會進入此分支，但是該分支下面的三個小分支都不會進入
if (mInTask == null) {
if (mSourceRecord == null) {//mSourceRecord不為null，此時的mSourceRecord為Launcher，不會進入此分支
...
} else if (mSourceRecord.launchMode == LAUNCH_SINGLE_INSTANCE) {//launcher應用activity的啟動模式為singleTask
...
} else if (mLaunchSingleInstance || mLaunchSingleTask) {//不會進入此分支，此時都為false
...
}
}
/*****************************************************************************/
//確定發起端的ActivityStack情況
computeSourceStack();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//確定發起端的Stack情況
private void computeSourceStack() {
if (mSourceRecord == null) {//mSourceRecord不為null，不會進入此分支
...
}
if (!mSourceRecord.finishing) {//此時明顯mSourceRecord沒有被finish所以會進入此分支
//當呼叫者Activity不為空，且不處于finishing狀態，則其所在堆疊賦于sourceStack
mSourceStack = mSourceRecord.task.stack;
return;
}
...
}
/*****************************************************************************/
mIntent.setFlags(mLaunchFlags);//設定目標Activity的launchMode啟動模式
// 根據mLaunchFlags來查找是否有可復用的activity
/**
* 這邊主要是判斷當前啟動的Activity是否存在可以利用的Task
* 當啟動模式launchMode為singleTask、singleInstance，或者啟動時
* Flag設定為FLAG_ACTIVITY_NEW_TASK并沒設定FLAG_ACTIVITY_MULTIPLE_TASK
* 并且當前啟動的Activity不是以startActivityForResult啟動的，
* 滿足以上情況才會尋找是否存在有復用的Task，
* 匹配規則：
* 1、對于啟動模式為singleInstance，遍歷所有ActivityStack和Task的堆疊中查找
*是否存在以當前啟動Activity相同的Activity，
* 2、其它情況下,遍歷所有ActivityStack和Task的堆疊，查找Task中intent變數 * 是否當前啟動Activity相匹配，如果不存在，則去匹配task的親和性（即
*在AndroidManifest中android:taskAffinity定義的，
*/
//此時肯定不存在復用的Activity，因為除開啟動了Launcher對應的Activity，啥都還沒有啟動呢
mReusedActivity = getReusableIntentActivity();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private ActivityRecord getReusableIntentActivity() {
//此時的mLaunchFlags的取值為FLAG_ACTIVITY_RESET_TASK_IF_NEEDED|FLAG_ACTIVITY_NEW_TASK，所以為true
boolean putIntoExistingTask = ((mLaunchFlags & FLAG_ACTIVITY_NEW_TASK) != 0 &&
(mLaunchFlags & FLAG_ACTIVITY_MULTIPLE_TASK) == 0)
|| mLaunchSingleInstance || mLaunchSingleTask;
//此時mInTask為false，mStartActivity.resultTo為null
putIntoExistingTask &= mInTask == null && mStartActivity.resultTo == null;
ActivityRecord intentActivity = null;
if (mOptions != null && mOptions.getLaunchTaskId() != -1) {
...
} else if (putIntoExistingTask) {
if (mLaunchSingleInstance) {//不會進入此分支
...
} else if ((mLaunchFlags & FLAG_ACTIVITY_LAUNCH_ADJACENT) != 0) {//不會進入此分支
...
} else {//會走入此分支，在ASS中查找是否存在啟動目標Activity，很明顯此時不存在，所以intentActivity得到的值為null
intentActivity = mSupervisor.findTaskLocked(mStartActivity);
}
}
return intentActivity;
}
/*****************************************************************************/
...
//如果找到了可重用的activity，則進行下一步相關操作，在此場景下很明顯沒有找到可復用的Activity
if (mReusedActivity != null) {//不會進入此分支，忽略
...
}
if (mStartActivity.packageName == null) {//例外處理,正常啟動不會進入此分支忽略
...
}
//是否需要啟動新的Activity標記，此場景下dontStart為false
final boolean dontStart = top != null && mStartActivity.resultTo == null
&& top.realActivity.equals(mStartActivity.realActivity)
&& top.userId == mStartActivity.userId
&& top.app != null && top.app.thread != null
&& ((mLaunchFlags & FLAG_ACTIVITY_SINGLE_TOP) != 0
|| mLaunchSingleTop || mLaunchSingleTask);
if (dontStart) {//不會走入此分支,忽略
...
}
//表示是否需要創建新的任務堆疊
boolean newTask = false;
...
/*
如果要啟動的目標Activity沒有對應的resultTo，很明顯由于mLaunchFlags攜帶FLAG_ACTIVITY_NEW_TASK所以result會被置為null
并且也沒有添加到對應堆疊中，mAddingToTask為false
而且設定了FLAG_ACTIVITY_NEW_TASK，
說明沒有找到對應的堆疊來啟動我們的Activity，
所以會通過創建或者復用一個堆疊來存放Activity
此場景下會進入該分支
*/
if (mStartActivity.resultTo == null && mInTask == null && !mAddingToTask
&& (mLaunchFlags & FLAG_ACTIVITY_NEW_TASK) != 0) {//此場景會進入此分支
newTask = true;
// 重用啟動端Activity所屬Task或者新建task
setTaskFromReuseOrCreateNewTask(taskToAffiliate);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//從發起端獲取Task任務堆疊或者新建一個任務堆疊
//此處的入參taskToAffiliate為null
private void setTaskFromReuseOrCreateNewTask(TaskRecord taskToAffiliate) {
//獲取目標ActivityStack堆疊，即目標Activity所屬的Stack堆疊
mTargetStack = computeStackFocus(mStartActivity, true, mLaunchBounds, mLaunchFlags,
mOptions);
if (mReuseTask == null) {//此時mReuseTask為null，會進入該分支
//創建新的Task
final TaskRecord task = mTargetStack.createTaskRecord(
mSupervisor.getNextTaskIdForUserLocked(mStartActivity.userId),
mNewTaskInfo != null ? mNewTaskInfo : mStartActivity.info,
mNewTaskIntent != null ? mNewTaskIntent : mIntent,
mVoiceSession, mVoiceInteractor, !mLaunchTaskBehind /* toTop */);
//將創建的Task設定為目標Activity的Task
mStartActivity.setTask(task, taskToAffiliate);
if (mLaunchBounds != null) {//此時的mLaunchBounds為null，不會進入此分支
...
}
} else {//不會進入此分支，因為此時的mReuseTask為null，在setInitialState被設定的，后續沒有被修改過
mStartActivity.setTask(mReuseTask, taskToAffiliate);
}
}
/*****************************************************************************/
...
if (!mMovedOtherTask) {//會走入此分支
updateTaskReturnToType(mStartActivity.task, mLaunchFlags, topStack);
}
}
/*
當mSourceRecord不為空，把新的ActivityRecord系結到啟動者的TaskRecord上，
一般情況下,mSourceRecord就是呼叫者,如本例中的Launcher;
但也有特殊情況,舉個例子,如果啟動模式為singleTask,堆疊中又不存在相同的Activity時,
mSourceRecord就是堆疊頂的Activity
*/
else if (mSourceRecord != null) {//不會進入此分支
...
} else if (mInTask != null) {//啟動時指定了目標堆疊（mInTask），ActivityRecord系結到mInTask，不會進入此分支
...
} else {//不會進入此分支
...
}
//權限檢測
mService.grantUriPermissionFromIntentLocked(mCallingUid, mStartActivity.packageName,
mIntent, mStartActivity.getUriPermissionsLocked(), mStartActivity.userId);
if (mSourceRecord != null && mSourceRecord.isRecentsActivity()) {//不會走入此分支，因為我們的發起端是Luancher不屬于RecentsActivity
...
}
...
/*把當前啟動的Activity加入TaskRecord以及系結WindowManagerService*/
mTargetStack.startActivityLocked(mStartActivity, newTask, mKeepCurTransition, mOptions);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
final void startActivityLocked( ActivityRecord r, //此時的r為目標Activity
boolean newTask, //newTask表示是否要創建Task，為true
boolean keepCurTransition,
ActivityOptions options)
{
TaskRecord rTask = r.task;
final int taskId = rTask.taskId;
if (!r.mLaunchTaskBehind && (taskForIdLocked(taskId) == null || newTask)) {//會進入此分支
//task中的上一個activity已被移除，或者ams重用該task,則將該task移到頂部
insertTaskAtTop(rTask, r);//將前面創建的Task放到Stack的頂部
mWindowManager.moveTaskToTop(taskId);
}
TaskRecord task = null;
if (!newTask) {//newTask為true不會走此分支
...
}
...
task = r.task;
//將Activity移動到Stack的頂端
task.addActivityToTop(r);
task.setFrontOfTask();
r.putInHistory();
if (!isHomeStack() || numActivities() > 0) {//會進入此分支，此時的ActivityStack不是HomeStack
//這個地方很重要
addConfigOverride(r, task);
} else {//不會進入此分支
...
}
...
}
/*****************************************************************************/
...
}
至此從Launcher桌面第一次啟動應用時Activity的Task以及Stack調度就完成了，我們對其小結一下，其主要流程可以精簡為如下幾個步驟:
- 呼叫AS.setInitialState方法，對啟動目標Activity時Task任務堆疊和ActivityStack堆疊將要涉及的變數進行初始化設定
- 根據發起端Activity的情況，呼叫computeLaunchingTaskFlags計算目標Activity的launchMode模式
- 呼叫computeSourceStack確定發起端Stack的情況
- 經過上述的一系列處理以后，已經確定目標Activity相關的LauncherMode，flag等啟動模式了，接下來呼叫getReusableIntentActivity確定是否有可復用的Activity，在此場景下肯定不會存在可以復用的Activity
- 接著呼叫方法setTaskFromReuseOrCreateNewTask創建目標Activity對應的Task和找到合適的Stack，并且將創建的Task移動到目標Stack的頂端
- 接著繼續呼叫ASS.startActivityLocked方法，將目標Activity加入TaskRecord，并且將其放入對應ActivityStack的頂部以及系結WindowManagerService
經過如上的步驟以后，我們的目標Activity所屬的Task和Stack就已經安排妥當了，我們此時可以通過命令查看，可以看到此時的mFocusedActivity和mFocusedStack為目標Activity，
#adb shell dumpsys activity activities
ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
Display #0 (activities from top to bottom):
Stack #1://目標Activity對應的Stackid，其值為FULLSCREEN_WORKSPACE_STACK_ID的值
mFullscreen=true
mBounds=null
Task id #9
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=1}
userId=0 effectiveUid=u0a48 mCallingUid=u0a23 mUserSetupComplete=true mCallingPackage=com.android.launcher3
affinity=com.example.test
intent={act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.test/.MainActivity}
realActivity=com.example.test/.MainActivity
autoRemoveRecents=false isPersistable=true numFullscreen=1 taskType=0 mTaskToReturnTo=1
rootWasReset=true mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=null lastThumbnailFile=/data/system_ce/0/recent_images/9_task_thumbnail.png
stackId=1
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=true firstActiveTime=1602505456984 lastActiveTime=1602505456984 (inactive for 3s)
* Hist #0: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
packageName=com.example.test processName=com.example.test
launchedFromUid=10023 launchedFromPackage=com.android.launcher3 userId=0
app=ProcessRecord{cd84720 15340:com.example.test/u0a48}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.test/.AMainActivity bnds=[184,356][360,544] }
frontOfTask=true task=TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=1}
taskAffinity=com.example.test
realActivity=com.example.test/.MainActivity
baseDir=/data/app/com.example.test-1/base.apk
dataDir=/data/user/0/com.example.test
stateNotNeeded=false componentSpecified=true mActivityType=0
compat={320dpi} labelRes=0x7f050000 icon=0x7f020000 theme=0x7f060001
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ffe6e6e6
launchFailed=false launchCount=1 lastLaunchTime=-3s640ms
haveState=false icicle=null
state=RESUMED stopped=false delayedResume=false finishing=false
keysPaused=false inHistory=true visible=true sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=0
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=APPLICATION_ACTIVITY_TYPE
waitingVisible=false nowVisible=true lastVisibleTime=-3s152ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=1}
Run #0: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
mResumedActivity: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
Stack #0:
mFullscreen=true
mBounds=null
Task id #8
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
userId=0 effectiveUid=u0a23 mCallingUid=0 mUserSetupComplete=true mCallingPackage=null
affinity=com.android.launcher3
intent={act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher}
realActivity=com.android.launcher3/.Launcher
autoRemoveRecents=false isPersistable=true numFullscreen=1 taskType=1 mTaskToReturnTo=1
rootWasReset=false mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=null lastThumbnailFile=/data/system_ce/0/recent_images/8_task_thumbnail.png
stackId=0
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=false firstActiveTime=1602505456850 lastActiveTime=1602505456850 (inactive for 3s)
* Hist #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
packageName=com.android.launcher3 processName=com.android.launcher3
launchedFromUid=0 launchedFromPackage=null userId=0
app=ProcessRecord{c4940bc 14811:com.android.launcher3/u0a23}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher }
frontOfTask=true task=TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
taskAffinity=com.android.launcher3
realActivity=com.android.launcher3/.Launcher
baseDir=/system/app/PaxLauncher3/PaxLauncher3.apk
dataDir=/data/user/0/com.android.launcher3
stateNotNeeded=true componentSpecified=false mActivityType=1
compat={320dpi} labelRes=0x7f0a0001 icon=0x7f030001 theme=0x7f0d0002
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ff222222
launchFailed=false launchCount=0 lastLaunchTime=-1m23s381ms
haveState=true icicle=Bundle[mParcelledData.dataSize=3788]
state=STOPPED stopped=true delayedResume=false finishing=false
keysPaused=false inHistory=true visible=false sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_NOT_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=2
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=HOME_ACTIVITY_TYPE
waitingVisible=false nowVisible=false lastVisibleTime=-7s845ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
Run #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mLastPausedActivity: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mFocusedActivity: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
mFocusedStack=ActivityStack{8238d9 stackId=1, 1 tasks} mLastFocusedStack=ActivityStack{8238d9 stackId=1, 1 tasks}
mSleepTimeout=false
mCurTaskIdForUser={0=9}
mUserStackInFront={}
mActivityContainers={0=ActivtyContainer{0}A, 1=ActivtyContainer{1}A}
mLockTaskModeState=NONE mLockTaskPackages (userId:packages)=
0:[]
mLockTaskModeTasks[]
1.2 從已經啟動應用的A Activity跳轉到B Activity
??通過這種方式啟動目標Activity較前面的啟動方式要簡單一些，因為無需創建新的Task了，只需要將目標Activity加入到A所屬的Task即可，注意此時啟動B Activity是標準的啟動方式，此時啟動目標B Activity的Task以及Stack調度執行如下所示:
//[ActivityStarter.java]
/*
這里的sourceRecord是指發起呼叫者
r是指本次的將要啟動的Activity
startFlags取值為0
doResume的值為true
inTask為發起方指定的任務堆疊，此時為null
這里主要確定目標Activity的launchMode Task堆疊等,即Task的創建和管理
*/
private int startActivityUnchecked(final ActivityRecord r,
ActivityRecord sourceRecord,
IVoiceInteractionSession voiceSession,
IVoiceInteractor voiceInteractor,
int startFlags,
boolean doResume,
ActivityOptions options,
TaskRecord inTask) {
//設定初始化狀態，此時需要重點關注該方法中的如下幾個目標值的獲取，為了分析的方便，我會將該方法展開
setInitialState(r, options, inTask, doResume, startFlags, sourceRecord, voiceSession,
voiceInteractor);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private void setInitialState(ActivityRecord r,
ActivityOptions options,
TaskRecord inTask,
boolean doResume,
int startFlags,
ActivityRecord sourceRecord,
IVoiceInteractionSession
voiceSession,
IVoiceInteractor voiceInteractor) {
//此處分支會走，將啟動程序中的涉及的相關變數進行初始化
reset();
...
mLaunchSingleTop = r.launchMode == LAUNCH_SINGLE_TOP;//此時為false
mLaunchSingleInstance = r.launchMode == LAUNCH_SINGLE_INSTANCE;//此時為false
mLaunchSingleTask = r.launchMode == LAUNCH_SINGLE_TASK;//此時為false
//這里重點關注一下，此時mIntent.getFlags攜帶的flags為0,此處很關鍵
mLaunchFlags = adjustLaunchFlagsToDocumentMode(r,mLaunchSingleInstance, mLaunchSingleTask, mIntent.getFlags());
...
mDoResume = doResume;
...
mInTask = inTask;
...
mStartFlags = startFlags;//此時的mStartFlags為0
}
/*****************************************************************************/
//根據發起端，計算目標Activity的launchMode模式
computeLaunchingTaskFlags();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//根據發起者launchMode情況，決定目標Activity的Flags情況
private void computeLaunchingTaskFlags() {
//此時場景下的mSourceRecord不為null，mInTask為null，所以不會進入該分支
if (mSourceRecord == null && mInTask != null && mInTask.stack != null) {
...
}else {//會進入此分支
mInTask = null;
//不滿足條件，不會進入該分支
if ((mStartActivity.isResolverActivity() || mStartActivity.noDisplay) && mSourceRecord != null
&& mSourceRecord.isFreeform()) {
mAddingToTask = true;
}
}
}
//此時的mInTask為null，會進入此分支，但是該分支下面的三個小分支都不會進入
if (mInTask == null) {
if (mSourceRecord == null) {//mSourceRecord不為null，此時的mSourceRecord為Launcher，不會進入此分支
...
} else if (mSourceRecord.launchMode == LAUNCH_SINGLE_INSTANCE) {//launcher應用activity的啟動模式為singleTask
...
} else if (mLaunchSingleInstance || mLaunchSingleTask) {//不會進入此分支，此時都為false
...
}
}
/*****************************************************************************/
//確定發起端的ActivityStack情況
computeSourceStack();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//確定發起端的Stack情況
private void computeSourceStack() {
if (mSourceRecord == null) {//mSourceRecord不為null，不會進入此分支
...
}
if (!mSourceRecord.finishing) {//此時明顯mSourceRecord沒有被finish所以會進入此分支
//當呼叫者Activity不為空，且不處于finishing狀態，則其所在堆疊賦于sourceStack
mSourceStack = mSourceRecord.task.stack;
return;
}
...
}
/*****************************************************************************/
mIntent.setFlags(mLaunchFlags);//設定目標Activity的launchMode啟動模式
// 根據mLaunchFlags來查找是否有可復用的activity
/**
* 這邊主要是判斷當前啟動的Activity是否存在可以利用的Task
* 當啟動模式launchMode為singleTask、singleInstance，或者啟動時
* Flag設定為FLAG_ACTIVITY_NEW_TASK并沒設定FLAG_ACTIVITY_MULTIPLE_TASK
* 并且當前啟動的Activity不是以startActivityForResult啟動的，
* 滿足以上情況才會尋找是否存在有復用的Task，
* 匹配規則：
* 1、對于啟動模式為singleInstance，遍歷所有ActivityStack和Task的堆疊中查找
*是否存在以當前啟動Activity相同的Activity，
* 2、其它情況下,遍歷所有ActivityStack和Task的堆疊，查找Task中intent變數 * 是否當前啟動Activity相匹配，如果不存在，則去匹配task的親和性（即
*在AndroidManifest中android:taskAffinity定義的，
*/
//此時肯定不存在復用的Activity，因為除開啟動了A對應的Activity，啥都還沒有啟動呢
mReusedActivity = getReusableIntentActivity();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private ActivityRecord getReusableIntentActivity() {
//此時的mLaunchFlags為0，而mLaunchSingleInstance為false，mLaunchSingleTask也為false，肯定不會存在可以復用的Activity
boolean putIntoExistingTask = ((mLaunchFlags & FLAG_ACTIVITY_NEW_TASK) != 0 &&
(mLaunchFlags & FLAG_ACTIVITY_MULTIPLE_TASK) == 0)
|| mLaunchSingleInstance || mLaunchSingleTask;
putIntoExistingTask &= mInTask == null && mStartActivity.resultTo == null;
ActivityRecord intentActivity = null;
if (mOptions != null && mOptions.getLaunchTaskId() != -1) {
...
} else if (putIntoExistingTask) {
...
}
return intentActivity;
}
/*****************************************************************************/
//如果找到了可重用的activity，則進行下一步相關操作，在此場景下很明顯沒有找到可復用的Activity
if (mReusedActivity != null) {//不會進入此分支，忽略
...
}
if (mStartActivity.packageName == null) {//例外處理,正常啟動不會進入此分支忽略
...
}
//是否需要啟動新的Activity標記，此場景下dontStart為false
final boolean dontStart = top != null && mStartActivity.resultTo == null
&& top.realActivity.equals(mStartActivity.realActivity)
&& top.userId == mStartActivity.userId
&& top.app != null && top.app.thread != null
&& ((mLaunchFlags & FLAG_ACTIVITY_SINGLE_TOP) != 0
|| mLaunchSingleTop || mLaunchSingleTask);
if (dontStart) {//不會走入此分支,忽略
...
}
//表示是否需要創建新的任務堆疊
boolean newTask = false;
...
/*
如果要啟動的目標Activity沒有對應的resultTo，
并且也沒有添加到對應堆疊中
而且設定了FLAG_ACTIVITY_NEW_TASK，
說明沒有找到對應的堆疊來啟動我們的Activity，
所以會通過創建或者復用一個堆疊來存放Activity
*/
//不會進入此分支
if (mStartActivity.resultTo == null && mInTask == null && !mAddingToTask
&& (mLaunchFlags & FLAG_ACTIVITY_NEW_TASK) != 0) {
... ...
}
/*
當mSourceRecord不為空，把新的ActivityRecord系結到啟動者的TaskRecord上，
此場景下會走入此分支，從發起端Activity A獲取Task以及它所屬的Stack
*/
else if (mSourceRecord != null) {
// 不是新建task的，重用原activity的task
final int result = setTaskFromSourceRecord();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private int setTaskFromSourceRecord() {
//獲取啟動Activity的任務堆疊
final TaskRecord sourceTask = mSourceRecord.task;
//此時的發起端Actiivty所在的TaskRecord就是處于sourceStack堆疊頂，所以sourceStack.topTask就是要啟動的Activity所在的堆疊
//如果目標Activity不允許在螢屏上顯示或者源任務堆疊和目標任務不在同一個堆疊
final boolean moveStackAllowed = sourceTask.stack.topTask() != sourceTask;
//獲取當前要啟動activity所屬的ActivityStack堆疊
if (moveStackAllowed) {//不會進入此分支
...
}
//目標ActivityStack為空
if (mTargetStack == null) {
mTargetStack = sourceTask.stack;//進入此分支
} else if (mTargetStack != sourceTask.stack) {
//把啟動方的任務堆疊系結到目標ActivityStack上
...
}
if (mDoResume) {
mTargetStack.moveToFront("sourceStackToFront");
}
//獲取目標ActivityStack的頂部task
final TaskRecord topTask = mTargetStack.topTask();
if (topTask != sourceTask && !mAvoidMoveToFront) {//不會走入此分支
}
//如果目標activity還沒有加入到堆疊中，而且啟動標志設定了CLEAR_TOP，那么我們將Activity添加到已經存在的任務堆疊中，并呼叫clear方法清空對應的activity
if (!mAddingToTask && (mLaunchFlags & FLAG_ACTIVITY_CLEAR_TOP) != 0) {//很明顯不會進入此分支
...
} else if (!mAddingToTask && (mLaunchFlags & FLAG_ACTIVITY_REORDER_TO_FRONT) != 0) {//不會進入此分支
...
}
mStartActivity.setTask(sourceTask, null);//設定目標Activity B的Task為A Activity所屬的Task
return START_SUCCESS;
}
/*****************************************************************************/
if (result != START_SUCCESS) {
return result;
}
} else if (mInTask != null) {//啟動時指定了目標堆疊（mInTask），ActivityRecord系結到mInTask,此場景下不會進入此分支
...
} else {//不會進入此分支，忽略
..,
}
...
/*把當前啟動的Activity加入TaskRecord以及系結WindowManagerService*/
mTargetStack.startActivityLocked(mStartActivity, newTask, mKeepCurTransition, mOptions);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
final void startActivityLocked( ActivityRecord r, //此時的r為目標Activity
boolean newTask, //newTask表示是否要創建Task，為true
boolean keepCurTransition,
ActivityOptions options)
{
TaskRecord rTask = r.task;
final int taskId = rTask.taskId;
if (!r.mLaunchTaskBehind && (taskForIdLocked(taskId) == null || newTask)) {//不會進入此分支
...
}
TaskRecord task = null;
if (!newTask) {//newTask為false會走入此分支
...
}
...
task = r.task;
//將Activity移動到Stack的頂端
task.addActivityToTop(r);
task.setFrontOfTask();
r.putInHistory();
if (!isHomeStack() || numActivities() > 0) {//會進入此分支，此時的ActivityStack不是HomeStack
//這個地方很重要
addConfigOverride(r, task);
} else {//不會進入此分支
...
}
...
}
/*****************************************************************************/
...
}
至此從從已經啟動應用的A Activity跳轉到B Activity的Task以及Stack的調度就完成了，我們對其小結一下，其主要流程可以精簡為如下幾個步驟:
- 呼叫AS.setInitialState方法，對啟動目標Activity時Task任務堆疊和ActivityStack堆疊將要涉及的變數進行初始化設定
- 根據發起端Activity的情況，呼叫computeLaunchingTaskFlags計算目標Activity的launchMode模式
- 呼叫computeSourceStack確定發起端Stack的情況
- 經過上述的一系列處理以后，已經確定目標Activity相關的LauncherMode，flag等啟動模式了，接下來呼叫getReusableIntentActivity確定是否有可復用的Activity，在此場景下肯定不會存在可以復用的Activity
- 接著呼叫方法setTaskFromSourceRecord從發起端Activity獲取Task和Stack
- 接著繼續呼叫ASS.startActivityLocked方法，將目標Activity加入TaskRecord，并且將其放入對應ActivityStack的頂部以及系結WindowManagerService
經過如上的步驟以后，我們的目標Activity所屬的Task和Stack就已經安排妥當了，我們此時可以通過命令查看，可以看到此時的mFocusedStack和Task為目標Activity A所對應的，
#adb shell dumpsys activity activities
ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
Display #0 (activities from top to bottom):
Stack #1://目標Activity對應的Stackid，其值為FULLSCREEN_WORKSPACE_STACK_ID的值
mFullscreen=true
mBounds=null
Task id #9
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
userId=0 effectiveUid=u0a48 mCallingUid=u0a23 mUserSetupComplete=true mCallingPackage=com.android.launcher3
affinity=com.example.test
intent={act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.test/.MainActivity}
realActivity=com.example.test/.MainActivity
autoRemoveRecents=false isPersistable=true numFullscreen=2 taskType=0 mTaskToReturnTo=1
rootWasReset=true mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}, ActivityRecord{59a829e u0 com.example.test/.BActivity t9}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=null lastThumbnailFile=/data/system_ce/0/recent_images/9_task_thumbnail.png
stackId=1
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=true firstActiveTime=1602505463616 lastActiveTime=1602505463616 (inactive for 2s)
* Hist #1: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}//任務堆疊頂Activity為BActivity
packageName=com.example.test processName=com.example.test
launchedFromUid=10048 launchedFromPackage=com.example.test userId=0
app=ProcessRecord{cd84720 15340:com.example.test/u0a48}
Intent { cmp=com.example.test/.BActivity }
frontOfTask=false task=TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
taskAffinity=com.example.test
realActivity=com.example.test/.BActivity
baseDir=/data/app/com.example.test-1/base.apk
dataDir=/data/user/0/com.example.test
stateNotNeeded=false componentSpecified=true mActivityType=0
compat={320dpi} labelRes=0x7f050000 icon=0x7f020000 theme=0x7f060001
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ffe6e6e6
launchFailed=false launchCount=1 lastLaunchTime=-2s860ms
haveState=false icicle=null
state=RESUMED stopped=false delayedResume=false finishing=false
keysPaused=false inHistory=true visible=true sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_NOT_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=0
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=APPLICATION_ACTIVITY_TYPE
waitingVisible=false nowVisible=true lastVisibleTime=-2s362ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
* Hist #0: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
packageName=com.example.test processName=com.example.test
launchedFromUid=10023 launchedFromPackage=com.android.launcher3 userId=0
app=ProcessRecord{cd84720 15340:com.example.test/u0a48}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.test/.AMainActivity bnds=[184,356][360,544] }
frontOfTask=true task=TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
taskAffinity=com.example.test
realActivity=com.example.test/.MainActivity
baseDir=/data/app/com.example.test-1/base.apk
dataDir=/data/user/0/com.example.test
stateNotNeeded=false componentSpecified=true mActivityType=0
compat={320dpi} labelRes=0x7f050000 icon=0x7f020000 theme=0x7f060001
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ffe6e6e6
launchFailed=false launchCount=0 lastLaunchTime=-9s493ms
haveState=true icicle=Bundle[mParcelledData.dataSize=1132]
state=STOPPED stopped=true delayedResume=false finishing=false
keysPaused=false inHistory=true visible=false sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=0
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=APPLICATION_ACTIVITY_TYPE
waitingVisible=false nowVisible=false lastVisibleTime=-9s5ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
Run #1: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}
Run #0: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
mResumedActivity: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}
mLastPausedActivity: ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}
Stack #0:
mFullscreen=true
mBounds=null
Task id #8
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
userId=0 effectiveUid=u0a23 mCallingUid=0 mUserSetupComplete=true mCallingPackage=null
affinity=com.android.launcher3
intent={act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher}
realActivity=com.android.launcher3/.Launcher
autoRemoveRecents=false isPersistable=true numFullscreen=1 taskType=1 mTaskToReturnTo=1
rootWasReset=false mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=null lastThumbnailFile=/data/system_ce/0/recent_images/8_task_thumbnail.png
stackId=0
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=false firstActiveTime=1602505456850 lastActiveTime=1602505456850 (inactive for 9s)
* Hist #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
packageName=com.android.launcher3 processName=com.android.launcher3
launchedFromUid=0 launchedFromPackage=null userId=0
app=ProcessRecord{c4940bc 14811:com.android.launcher3/u0a23}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher }
frontOfTask=true task=TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
taskAffinity=com.android.launcher3
realActivity=com.android.launcher3/.Launcher
baseDir=/system/app/PaxLauncher3/PaxLauncher3.apk
dataDir=/data/user/0/com.android.launcher3
stateNotNeeded=true componentSpecified=false mActivityType=1
compat={320dpi} labelRes=0x7f0a0001 icon=0x7f030001 theme=0x7f0d0002
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ff222222
launchFailed=false launchCount=0 lastLaunchTime=-1m29s234ms
haveState=true icicle=Bundle[mParcelledData.dataSize=3788]
state=STOPPED stopped=true delayedResume=false finishing=false
keysPaused=false inHistory=true visible=false sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_NOT_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=2
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=HOME_ACTIVITY_TYPE
waitingVisible=false nowVisible=false lastVisibleTime=-13s698ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
Run #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mLastPausedActivity: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mFocusedActivity: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}//焦點Activity為BActivity
mFocusedStack=ActivityStack{8238d9 stackId=1, 1 tasks} mLastFocusedStack=ActivityStack{8238d9 stackId=1, 1 tasks}
mSleepTimeout=false
mCurTaskIdForUser={0=9}
mUserStackInFront={}
mActivityContainers={0=ActivtyContainer{0}A, 1=ActivtyContainer{1}A}
mLockTaskModeState=NONE mLockTaskPackages (userId:packages)=
0:[]
mLockTaskModeTasks[]
1.3 按Home按鍵退出應用，然后重新打開應用
??我們先不除錯，我們想想想此時場景下會怎么處理呢！此時的Task相關的調度邏輯如下，此時會先找到已有的相關task，并顯示堆疊頂的Activity，任務調度執行如下所示：
//[ActivityStarter.java]
/*
這里的sourceRecord是指發起呼叫者
r是指本次的將要啟動的Activity
startFlags取值為0
doResume的值為true
inTask為發起方指定的任務堆疊，此時為null
這里主要確定目標Activity的launchMode Task堆疊等,即Task的創建和管理
*/
private int startActivityUnchecked(final ActivityRecord r,
ActivityRecord sourceRecord,
IVoiceInteractionSession voiceSession,
IVoiceInteractor voiceInteractor,
int startFlags,
boolean doResume,
ActivityOptions options,
TaskRecord inTask) {
//設定初始化狀態，此時需要重點關注該方法中的如下幾個目標值的獲取，為了分析的方便，我會將該方法展開
setInitialState(r, options, inTask, doResume, startFlags, sourceRecord, voiceSession,
voiceInteractor);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private void setInitialState(ActivityRecord r,
ActivityOptions options,
TaskRecord inTask,
boolean doResume,
int startFlags,
ActivityRecord sourceRecord,
IVoiceInteractionSession
voiceSession,
IVoiceInteractor voiceInteractor) {
//此處分支會走，將啟動程序中的涉及的相關變數進行初始化
reset();
...
mLaunchSingleTop = r.launchMode == LAUNCH_SINGLE_TOP;//此時為false
mLaunchSingleInstance = r.launchMode == LAUNCH_SINGLE_INSTANCE;//此時為false
mLaunchSingleTask = r.launchMode == LAUNCH_SINGLE_TASK;//此時為false
//這里重點關注一下，此時mIntent.getFlags攜帶的flags為0,此處很關鍵
mLaunchFlags = adjustLaunchFlagsToDocumentMode(r,mLaunchSingleInstance, mLaunchSingleTask, mIntent.getFlags());
...
mDoResume = doResume;
...
mInTask = inTask;
...
mStartFlags = startFlags;//此時的mStartFlags為0
}
/*****************************************************************************/
//根據發起端，計算目標Activity的launchMode模式
computeLaunchingTaskFlags();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//根據發起者launchMode情況，決定目標Activity的Flags情況
private void computeLaunchingTaskFlags() {
//此時場景下的mSourceRecord不為null，mInTask為null，所以不會進入該分支
if (mSourceRecord == null && mInTask != null && mInTask.stack != null) {
...
}else {//會進入此分支
mInTask = null;
//不滿足條件，不會進入該分支
if ((mStartActivity.isResolverActivity() || mStartActivity.noDisplay) && mSourceRecord != null
&& mSourceRecord.isFreeform()) {
mAddingToTask = true;
}
}
}
//此時的mInTask為null，會進入此分支，但是該分支下面的三個小分支都不會進入
if (mInTask == null) {
if (mSourceRecord == null) {//mSourceRecord不為null，此時的mSourceRecord為Launcher，不會進入此分支
...
} else if (mSourceRecord.launchMode == LAUNCH_SINGLE_INSTANCE) {//launcher應用activity的啟動模式為singleTask
...
} else if (mLaunchSingleInstance || mLaunchSingleTask) {//不會進入此分支，此時都為false
...
}
}
/*****************************************************************************/
//確定發起端的ActivityStack情況
computeSourceStack();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
//確定發起端的Stack情況
private void computeSourceStack() {
if (mSourceRecord == null) {//mSourceRecord不為null，不會進入此分支
...
}
if (!mSourceRecord.finishing) {//此時明顯mSourceRecord沒有被finish所以會進入此分支
//當呼叫者Activity不為空，且不處于finishing狀態，則其所在堆疊賦于sourceStack
mSourceStack = mSourceRecord.task.stack;
return;
}
...
}
/*****************************************************************************/
mIntent.setFlags(mLaunchFlags);//設定目標Activity的launchMode啟動模式
// 根據mLaunchFlags來查找是否有可復用的activity
/**
* 這邊主要是判斷當前啟動的Activity是否存在可以利用的Task
* 當啟動模式launchMode為singleTask、singleInstance，或者啟動時
* Flag設定為FLAG_ACTIVITY_NEW_TASK并沒設定FLAG_ACTIVITY_MULTIPLE_TASK
* 并且當前啟動的Activity不是以startActivityForResult啟動的，
* 滿足以上情況才會尋找是否存在有復用的Task，
* 匹配規則：
* 1、對于啟動模式為singleInstance，遍歷所有ActivityStack和Task的堆疊中查找
*是否存在以當前啟動Activity相同的Activity，
* 2、其它情況下,遍歷所有ActivityStack和Task的堆疊，查找Task中intent變數 * 是否當前啟動Activity相匹配，如果不存在，則去匹配task的親和性（即
*在AndroidManifest中android:taskAffinity定義的，
*/
//此時存在復用額Activity，因為我們前面已經創建了目標Activity而且沒有被銷毀
mReusedActivity = getReusableIntentActivity();
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private ActivityRecord getReusableIntentActivity() {
//此時的mLaunchFlags的取值為FLAG_ACTIVITY_RESET_TASK_IF_NEEDED|FLAG_ACTIVITY_NEW_TASK，所以為true
boolean putIntoExistingTask = ((mLaunchFlags & FLAG_ACTIVITY_NEW_TASK) != 0 &&
(mLaunchFlags & FLAG_ACTIVITY_MULTIPLE_TASK) == 0)
|| mLaunchSingleInstance || mLaunchSingleTask;
//此時mInTask為false，mStartActivity.resultTo為null
putIntoExistingTask &= mInTask == null && mStartActivity.resultTo == null;
ActivityRecord intentActivity = null;
if (mOptions != null && mOptions.getLaunchTaskId() != -1) {
...
} else if (putIntoExistingTask) {
if (mLaunchSingleInstance) {//不會進入此分支
...
} else if ((mLaunchFlags & FLAG_ACTIVITY_LAUNCH_ADJACENT) != 0) {//不會進入此分支
...
} else {//會走入此分支，在ASS中查找是否存在啟動目標Activity，很明顯此時存在，所以intentActivity得到的值為Activity B
intentActivity = mSupervisor.findTaskLocked(mStartActivity);
}
}
return intentActivity;
}
/*****************************************************************************/
//如果找到了可重用的activity，需要清理掉原來的資訊，并把當前啟動的activity的資訊拷貝進去
//做清理和拷貝作業，此時會進入此分支
if (mReusedActivity != null) {
...
//設定當前啟動Activity的Task為復用的Task,進入此分支
if (mStartActivity.task == null) {
mStartActivity.task = mReusedActivity.task;
}
/*
*這邊處理啟動時設定FLAG_ACTIVITY_CLEAR_TOP時，要清除復用Task中存在與當前啟動
*Activity相同的Activity之上的Activity
*舉個例子：比如復用Task1中存在有Activity A,B,C,D,此時正在啟動的Activity B，那么C**和D也要finish,另外此時如果B *為標準啟動模式，并且沒有設定FLAG_ACTIVITY_SINGLE_TOP，那么B也會finish，具體的讀者可以跟進
*mReusedActivity.task.performClearTaskForReuseLocked看下，
*/
if ((mLaunchFlags & FLAG_ACTIVITY_CLEAR_TOP) != 0
|| mLaunchSingleInstance || mLaunchSingleTask) {//不會進入此分支
...
}
// 計算哪個task和activity要移至前臺，必要時會進行task的清理作業
mReusedActivity = setTargetStackAndMoveToFrontIfNeeded(mReusedActivity);
/*****************************************************************************/
//這里小伙們就不要關注排版問題了，主要是為了演示整個流程，各位就將就一下
private ActivityRecord setTargetStackAndMoveToFrontIfNeeded(ActivityRecord intentActivity) {
mTargetStack = intentActivity.task.stack;
mTargetStack.mLastPausedActivity = null;
final ActivityStack focusStack = mSupervisor.getFocusedStack();
ActivityRecord curTop = (focusStack == null)
? null : focusStack.topRunningNonDelayedActivityLocked(mNotTop);//獲取當前前臺ActivityStack堆疊頂的ActivityRecord
//判斷頂部的堆疊是否符合要求(即判斷現在堆疊頂的堆疊是否為能夠復用的activityrecord所在的堆疊)
if (curTop != null
&& (curTop.task != intentActivity.task || curTop.task != focusStack.topTask())
&& !mAvoidMoveToFront) {
//增加一個標記，標識這個task是從任務堆疊的后面移動上來的
mStartActivity.intent.addFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
//這里的mSourceRecord表示的是發起端，此處是判斷合法性
if (mSourceRecord == null || (mSourceStack.topActivity() != null &&
mSourceStack.topActivity().task == mSourceRecord.task)) {//次場景會進入此分支
if (mLaunchTaskBehind && mSourceRecord != null) {//此時的mLaunchTaskBehind為null不進入此分支
...
}
mMovedOtherTask = true;
final boolean willClearTask =
(mLaunchFlags & (FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TASK))
== (FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TASK);//此時willClearTask 的取值為false
if (!willClearTask) {//不需要清空，那么就需要將復用的task移至堆疊頂
//根據規則獲取當前要啟動activity所屬的ActivityStack堆疊
final ActivityStack launchStack = getLaunchStack(
mStartActivity, mLaunchFlags, mStartActivity.task, mOptions);
//當要啟動的堆疊與目標一致或者要啟動的堆疊為空，這是我們一般的標準流程，會呼叫moveTaskToFrontLocked方法，將當前堆疊移動到與用戶互動的堆疊頂
//此時會進入該分支
if (launchStack == null || launchStack == mTargetStack) {
mTargetStack.moveTaskToFrontLocked(
intentActivity.task, mNoAnimation, mOptions,
mStartActivity.appTimeTracker, "bringingFoundTaskToFront");
mMovedToFront = true;
} else if (launchStack.mStackId == DOCKED_STACK_ID
|| launchStack.mStackId == FULLSCREEN_WORKSPACE_STACK_ID) {//不會進入該分支
...
}
mOptions = null;
}
updateTaskReturnToType(intentActivity.task, mLaunchFlags, focusStack);
}
}
if (!mMovedToFront && mDoResume) {//不進入此分支
...
}
mSupervisor.handleNonResizableTaskIfNeeded(intentActivity.task, INVALID_STACK_ID,
mTargetStack.mStackId);
//此時Luancher啟動的時候攜帶了該值，所以會走入此分支
if ((mLaunchFlags & FLAG_ACTIVITY_RESET_TASK_IF_NEEDED) != 0) {
return mTargetStack.resetTaskIfNeededLocked(intentActivity, mStartActivity);
}
...
}
/*****************************************************************************/
setTaskFromIntentActivity(mReusedActivity);
if (!mAddingToTask && mReuseTask == null) {//進入此分支
resumeTargetStackIfNeeded();
Log.e(ACTIVITY_TAG, "mReusedActivity != null START_TASK_TO_FRONT");
return START_TASK_TO_FRONT;
}
}
}
至此從按Home按鍵退出應用，然后重新打開應用的Task以及Stack的調度就完成了，我們對其小結一下，其主要流程可以精簡為如下幾個步驟:
- 呼叫AS.setInitialState方法，對啟動目標Activity時Task任務堆疊和ActivityStack堆疊將要涉及的變數進行初始化設定
- 根據發起端Activity的情況，呼叫computeLaunchingTaskFlags計算目標Activity的launchMode模式
- 呼叫computeSourceStack確定發起端Stack的情況
- 經過上述的一系列處理以后，已經確定目標Activity相關的LauncherMode，flag等啟動模式了，接下來呼叫getReusableIntentActivity確定是否有可復用的Activity，在此場景下存在復用的Activity
- 進入存在復用Activity的分支，呼叫setTargetStackAndMoveToFrontIfNeeded處理復用的Activity和Task以及Stack
- 接著直接呼叫resumeTargetStackIfNeeded恢復復用Task任務堆疊
經過如上的步驟以后，我們的目標Activity所屬的Task和Stack就已經安排妥當了，我們此時可以通過命令查看相對應的Task任務堆疊和Stack堆疊了，
#adb shell dumpsys activity activities
ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
Display #0 (activities from top to bottom):
Stack #1:
mFullscreen=true
mBounds=null
Task id #9
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
userId=0 effectiveUid=u0a48 mCallingUid=u0a23 mUserSetupComplete=true mCallingPackage=com.android.launcher3
affinity=com.example.test
intent={act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.test/.MainActivity}
realActivity=com.example.test/.MainActivity
autoRemoveRecents=false isPersistable=true numFullscreen=2 taskType=0 mTaskToReturnTo=1
rootWasReset=true mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{dd0bb9a u0 com.example.test/.AMainActivity t9}, ActivityRecord{59a829e u0 com.example.test/.BActivity t9}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=android.graphics.Bitmap@d88386f lastThumbnailFile=/data/system_ce/0/recent_images/9_task_thumbnail.png
stackId=1
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=true firstActiveTime=1602505471813 lastActiveTime=1602505471813 (inactive for 4s)
* Hist #1: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}
packageName=com.example.test processName=com.example.test
launchedFromUid=10048 launchedFromPackage=com.example.test userId=0
app=ProcessRecord{cd84720 15340:com.example.test/u0a48}
Intent { cmp=com.example.test/.BActivity bnds=[184,356][360,544] }
frontOfTask=false task=TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
taskAffinity=com.example.test
realActivity=com.example.test/.BActivity
baseDir=/data/app/com.example.test-1/base.apk
dataDir=/data/user/0/com.example.test
stateNotNeeded=false componentSpecified=true mActivityType=0
compat={320dpi} labelRes=0x7f050000 icon=0x7f020000 theme=0x7f060001
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ffe6e6e6
launchFailed=false launchCount=0 lastLaunchTime=-12s222ms
haveState=false icicle=null
state=RESUMED stopped=false delayedResume=false finishing=false
keysPaused=false inHistory=true visible=true sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_NOT_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=0
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=APPLICATION_ACTIVITY_TYPE
waitingVisible=false nowVisible=true lastVisibleTime=-3s634ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
* Hist #0: ActivityRecord{dd0bb9a u0 com.example.test/.MainActivity t9}
packageName=com.example.test processName=com.example.test
launchedFromUid=10023 launchedFromPackage=com.android.launcher3 userId=0
app=ProcessRecord{cd84720 15340:com.example.test/u0a48}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.test/.MainActivity bnds=[184,356][360,544] }
frontOfTask=true task=TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
taskAffinity=com.example.test
realActivity=com.example.test/.MainActivity
baseDir=/data/app/com.example.test-1/base.apk
dataDir=/data/user/0/com.example.test
stateNotNeeded=false componentSpecified=true mActivityType=0
compat={320dpi} labelRes=0x7f050000 icon=0x7f020000 theme=0x7f060001
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ffe6e6e6
launchFailed=false launchCount=0 lastLaunchTime=-18s855ms
haveState=true icicle=Bundle[mParcelledData.dataSize=1132]
state=STOPPED stopped=true delayedResume=false finishing=false
keysPaused=false inHistory=true visible=false sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=0
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=APPLICATION_ACTIVITY_TYPE
waitingVisible=false nowVisible=false lastVisibleTime=-18s367ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{d361623 #9 A=com.example.test U=0 StackId=1 sz=2}
Run #1: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}
Run #0: ActivityRecord{dd0bb9a u0 com.example.test/.MainActivity t9}
mResumedActivity: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}
Stack #0:
mFullscreen=true
mBounds=null
Task id #8
mFullscreen=true
mBounds=null
mMinWidth=-1
mMinHeight=-1
mLastNonFullscreenBounds=null
* TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
userId=0 effectiveUid=u0a23 mCallingUid=1000 mUserSetupComplete=true mCallingPackage=android
affinity=com.android.launcher3
intent={act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher}
realActivity=com.android.launcher3/.Launcher
autoRemoveRecents=false isPersistable=true numFullscreen=1 taskType=1 mTaskToReturnTo=0
rootWasReset=false mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
Activities=[ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}]
askedCompatMode=false inRecents=true isAvailable=true
lastThumbnail=null lastThumbnailFile=/data/system_ce/0/recent_images/8_task_thumbnail.png
stackId=0
hasBeenVisible=true mResizeMode=RESIZE_MODE_FORCE_RESIZEABLE isResizeable=false firstActiveTime=1602505471784 lastActiveTime=1602505471784 (inactive for 4s)
* Hist #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
packageName=com.android.launcher3 processName=com.android.launcher3
launchedFromUid=0 launchedFromPackage=null userId=0
app=ProcessRecord{c4940bc 14811:com.android.launcher3/u0a23}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher }
frontOfTask=true task=TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
taskAffinity=com.android.launcher3
realActivity=com.android.launcher3/.Launcher
baseDir=/system/app/PaxLauncher3/PaxLauncher3.apk
dataDir=/data/user/0/com.android.launcher3
stateNotNeeded=true componentSpecified=false mActivityType=1
compat={320dpi} labelRes=0x7f0a0001 icon=0x7f030001 theme=0x7f0d0002
config={1.0 ?mcc?mnc [zh_CN] ldltr sw360dp w360dp h568dp 320dpi nrml port finger -keyb/v/h -nav/h s.5}
taskConfigOverride={1.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/?}
taskDescription: iconFilename=null label="null" color=ff222222
launchFailed=false launchCount=0 lastLaunchTime=-1m38s596ms
haveState=true icicle=Bundle[mParcelledData.dataSize=3788]
state=STOPPED stopped=true delayedResume=false finishing=false
keysPaused=false inHistory=true visible=false sleeping=false idle=true mStartingWindowState=STARTING_WINDOW_NOT_SHOWN
fullscreen=true noDisplay=false immersive=false launchMode=2
frozenBeforeDestroy=false forceNewConfig=false
mActivityType=HOME_ACTIVITY_TYPE
waitingVisible=false nowVisible=false lastVisibleTime=-5s891ms
resizeMode=RESIZE_MODE_FORCE_RESIZEABLE
Running activities (most recent first):
TaskRecord{3a6c4af #8 A=com.android.launcher3 U=0 StackId=0 sz=1}
Run #0: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mLastPausedActivity: ActivityRecord{d5e92f9 u0 com.android.launcher3/.Launcher t8}
mFocusedActivity: ActivityRecord{59a829e u0 com.example.test/.BActivity t9}
mFocusedStack=ActivityStack{8238d9 stackId=1, 1 tasks} mLastFocusedStack=ActivityStack{8238d9 stackId=1, 1 tasks}
mSleepTimeout=false
mCurTaskIdForUser={0=9}
mUserStackInFront={}
mActivityContainers={0=ActivtyContainer{0}A, 1=ActivtyContainer{1}A}
mLockTaskModeState=NONE mLockTaskPackages (userId:packages)=
0:[]
mLockTaskModeTasks[]
總結
??Activity啟動流程(三)- Activity Task調度演算法復盤分析到這里就要告一段落了，從前面的分析可以看出來，Activity和Task的調度演算法非常復雜，最好需結合實際場景才好分析，只有這樣才知道是否需要新建Task,還是將新的ActivityRecord加入到已有的Task里，當前這一切的前提條件是我們能理解啟動模式的一些特點，這樣才能對理解調度演算法有一個基礎，如果一上來就是懵懵懂懂的亂干那就完蛋了，因為你會被這原始碼繞的暈頭轉向的搞不清方向了，好了今天就到這里了，希望小伙們能點贊和關注，謝謝！
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標籤：其他