android开发浅谈之ActivityDisplay/ActivityStack/TaskRecord/ActivityRecord-优快云博客

本文链接：https://blog.youkuaiyun.com/hfreeman2008/article/details/113309272

本文详细介绍了Android系统中ActivityDisplay、ActivityStack、TaskRecord和ActivityRecord这四个关键类的关系及其在活动管理中的作用。通过adb shell dumpsys activity activities命令的输出，展示了它们如何组织应用程序的运行状态。ActivityDisplay管理多个ActivityStack，每个ActivityStack包含一个或多个TaskRecord，而TaskRecord则包含一系列ActivityRecord。ActivityRecord代表单个活动实例，TaskRecord和ActivityStack则负责任务和堆栈的管理。文章还解释了这些类在启动活动过程中的创建和关联，以及它们如何与WindowManagerService交互。

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ActivityDisplay/ActivityStack/TaskRecord/ActivityRecord,这几个关键的类，我以前一直搞不清其具体关系，看了android里面的Activity体系结构(1)_ActivityDisplay/ActivityStack/TaskRecord/ActivityRecord这篇文章后，才有了一点点明白，对应也做一个笔记。

四个类的整体关系图如下

我直接复制他的图片：

在这里插入图片描述
通过adb shell dumpsys activity activities 命令可以看到如下打印：

ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
Display #0 (activities from top to bottom):

  Stack #2: type=standard mode=fullscreen
  isSleeping=false
  mBounds=Rect(0, 0 - 0, 0)
    Task id #89
    mBounds=Rect(0, 0 - 0, 0)
    mMinWidth=-1
    mMinHeight=-1
    mLastNonFullscreenBounds=null
    * TaskRecord{d966e2f #89 A=com.android.messaging U=0 StackId=2 sz=1}
      userId=0 effectiveUid=u0a50 mCallingUid=1000 mUserSetupComplete=true mCallingPackage=com.android.launcher3
      affinity=com.android.messaging
      intent={act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.android.messaging/.ui.conversationlist.ConversationListActivity}
      mActivityComponent=com.android.messaging/.ui.conversationlist.ConversationListActivity
      autoRemoveRecents=false isPersistable=true numFullscreen=1 activityType=1
      rootWasReset=true mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
      Activities=[ActivityRecord{8bc12ef u0 com.android.messaging/.ui.conversationlist.ConversationListActivity t89}]
      askedCompatMode=false inRecents=true isAvailable=true
      mRootProcess=ProcessRecord{83e347 4227:com.android.messaging/u0a50}
      stackId=2
      hasBeenVisible=true mResizeMode=RESIZE_MODE_RESIZEABLE_VIA_SDK_VERSION mSupportsPictureInPicture=false isResizeable=true lastActiveTime=179867 (inactive for 36s)
      * Hist #0: ActivityRecord{8bc12ef u0 com.android.messaging/.ui.conversationlist.ConversationListActivity t89}
          packageName=com.android.messaging processName=com.android.messaging
          launchedFromUid=1000 launchedFromPackage=com.android.launcher3 userId=0
          app=ProcessRecord{83e347 4227:com.android.messaging/u0a50}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.android.messaging/.ui.conversationlist.ConversationListActivity bnds=[616,1383][909,1575] }
          frontOfTask=true task=TaskRecord{d966e2f #89 A=com.android.messaging U=0 StackId=2 sz=1}
          taskAffinity=com.android.messaging
          mActivityComponent=com.android.messaging/.ui.conversationlist.ConversationListActivity
          baseDir=/system/priv-app/Messaging_royole/Messaging_royole.apk
          dataDir=/data/user/0/com.android.messaging
          stateNotNeeded=false componentSpecified=true mActivityType=standard
          compat={320dpi always-compat} labelRes=0x7f12005b icon=0x7f0801d9 theme=0x7f130102
          mLastReportedConfigurations:
           mGlobalConfig={ 1.0 ?mcc?mnc [zh_CN] ldltr sw760dp w760dp h738dp 320dpi lrg hdr port finger -keyb/v/h -nav/h winConfig={ mBounds=Rect(0, 0 - 1520, 1620) mAppBounds=Rect(0, 0 - 1520, 1524) mWindowingMode=fullscreen mDisplayWindowingMode=fullscreen mActivityType=undefined mAlwaysOnTop=undefined mRotation=ROTATION_0} s.8}
           mOverrideConfig={ 1.0 ?mcc?mnc [zh_CN] ldltr sw760dp w760dp h738dp 320dpi lrg hdr port finger -keyb/v/h -nav/h winConfig={ mBounds=Rect(0, 0 - 1520, 1620) mAppBounds=Rect(0, 0 - 1520, 1524) mWindowingMode=fullscreen mDisplayWindowingMode=fullscreen mActivityType=standard mAlwaysOnTop=undefined mRotation=ROTATION_0} s.1}
          CurrentConfiguration={ 1.0 ?mcc?mnc [zh_CN] ldltr sw760dp w760dp h738dp 320dpi lrg hdr port finger -keyb/v/h -nav/h winConfig={ mBounds=Rect(0, 0 - 1520, 1620) mAppBounds=Rect(0, 0 - 1520, 1524) mWindowingMode=fullscreen mDisplayWindowingMode=fullscreen mActivityType=standard mAlwaysOnTop=undefined mRotation=ROTATION_0} s.1}
          taskDescription: label="null" icon=null iconResource=0 iconFilename=null primaryColor=ffffffff
           backgroundColor=fffafafa
           statusBarColor=0
           navigationBarColor=ffffffff
          launchFailed=false launchCount=1 lastLaunchTime=-36s625ms
          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=standard
           nowVisible=true lastVisibleTime=-36s123ms
          resizeMode=RESIZE_MODE_RESIZEABLE_VIA_SDK_VERSION
          mLastReportedMultiWindowMode=false mLastReportedPictureInPictureMode=false

    Running activities (most recent first):
      TaskRecord{d966e2f #89 A=com.android.messaging U=0 StackId=2 sz=1}
        Run #0: ActivityRecord{8bc12ef u0 com.android.messaging/.ui.conversationlist.ConversationListActivity t89}

    mResumedActivity: ActivityRecord{8bc12ef u0 com.android.messaging/.ui.conversationlist.ConversationListActivity t89}

  Stack #0: type=home mode=fullscreen
  isSleeping=false
  mBounds=Rect(0, 0 - 0, 0)

    Task id #87
    mBounds=Rect(0, 0 - 0, 0)
    mMinWidth=-1
    mMinHeight=-1
    mLastNonFullscreenBounds=null
    * TaskRecord{5f96c3c #87 I=com.android.launcher3/.Launcher U=0 StackId=0 sz=1}
      userId=0 effectiveUid=1000 mCallingUid=0 mUserSetupComplete=true mCallingPackage=null
      intent={act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher}
      mActivityComponent=com.android.launcher3/.Launcher
      autoRemoveRecents=false isPersistable=true numFullscreen=1 activityType=2
      rootWasReset=false mNeverRelinquishIdentity=true mReuseTask=false mLockTaskAuth=LOCK_TASK_AUTH_PINNABLE
      Activities=[ActivityRecord{12984fc u0 com.android.launcher3/.Launcher t87}]
      askedCompatMode=false inRecents=true isAvailable=true
      mRootProcess=ProcessRecord{48bd69b 2716:com.android.launcher3/1000}
      stackId=0
      hasBeenVisible=true mResizeMode=RESIZE_MODE_RESIZEABLE mSupportsPictureInPicture=false isResizeable=true lastActiveTime=179789 (inactive for 36s)
      * Hist #0: ActivityRecord{12984fc u0 com.android.launcher3/.Launcher t87}
          packageName=com.android.launcher3 processName=com.android.launcher3
          launchedFromUid=0 launchedFromPackage=null userId=0
          app=ProcessRecord{48bd69b 2716:com.android.launcher3/1000}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10000100 cmp=com.android.launcher3/.Launcher }
          frontOfTask=true task=TaskRecord{5f96c3c #87 I=com.android.launcher3/.Launcher U=0 StackId=0 sz=1}
          taskAffinity=null
          mActivityComponent=com.android.launcher3/.Launcher
          baseDir=/system/priv-app/Launcher_royole/Launcher_royole.apk
          dataDir=/data/user/0/com.android.launcher3
          stateNotNeeded=true componentSpecified=false mActivityType=home
          compat={320dpi always-compat} labelRes=0x7f11009f icon=0x7f0e0005 theme=0x7f120017
          mLastReportedConfigurations:
           mGlobalConfig={ 1.0 ?mcc?mnc [zh_CN] ldltr sw760dp w760dp h738dp 320dpi lrg hdr port finger -keyb/v/h -nav/h winConfig={ mBounds=Rect(0, 0 - 1520, 1620) mAppBounds=Rect(0, 0 - 1520, 1524) mWindowingMode=fullscreen mDisplayWindowingMode=fullscreen mActivityType=undefined mAlwaysOnTop=undefined mRotation=ROTATION_0} s.17}
           mOverrideConfig={ 1.0 ?mcc?mnc [zh_CN] ldltr sw760dp w760dp h738dp 320dpi lrg hdr port finger -keyb/v/h -nav/h winConfig={ mBounds=Rect(0, 0 - 1520, 1620) mAppBounds=Rect(0, 0 - 1520, 1524) mWindowingMode=fullscreen mDisplayWindowingMode=fullscreen mActivityType=home mAlwaysOnTop=undefined mRotation=ROTATION_0} s.2}
          CurrentConfiguration={ 1.0 ?mcc?mnc [zh_CN] ldltr sw760dp w760dp h738dp 320dpi lrg hdr port finger -keyb/v/h -nav/h winConfig={ mBounds=Rect(0, 0 - 1520, 1620) mAppBounds=Rect(0, 0 - 1520, 1524) mWindowingMode=fullscreen mDisplayWindowingMode=fullscreen mActivityType=home mAlwaysOnTop=undefined mRotation=ROTATION_0} s.2}
          RequestedOverrideConfiguration={null 0.0 ?mcc?mnc ?localeList ?layoutDir ?swdp ?wdp ?hdp ?density ?lsize ?long ?ldr ?wideColorGamut ?orien ?uimode ?night ?touch ?keyb/?/? ?nav/? winConfig={ mBounds=Rect(0, 0 - 0, 0) mAppBounds=null mWindowingMode=undefined mDisplayWindowingMode=undefined mActivityType=home mAlwaysOnTop=undefined mRotation=undefined}}
          taskDescription: label="null" icon=null iconResource=0 iconFilename=null primaryColor=fff5f5f5
           backgroundColor=fffafafa
           statusBarColor=0
           navigationBarColor=0
          launchFailed=false launchCount=0 lastLaunchTime=-1m17s119ms
          haveState=true icicle=Bundle[mParcelledData.dataSize=10292]
          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
           nowVisible=false lastVisibleTime=-45s897ms
          connections={ConnectionRecord{4665a11 u0 CR com.android.launcher3/com.royole.sidesplitscreen.SideSplitScreenService:@1cfca38}}
          resizeMode=RESIZE_MODE_RESIZEABLE
          mLastReportedMultiWindowMode=false mLastReportedPictureInPictureMode=false

    Running activities (most recent first):
      TaskRecord{5f96c3c #87 I=com.android.launcher3/.Launcher U=0 StackId=0 sz=1}
        Run #0: ActivityRecord{12984fc u0 com.android.launcher3/.Launcher t87}

    mLastPausedActivity: ActivityRecord{12984fc u0 com.android.launcher3/.Launcher t87}

 ResumedActivity:ActivityRecord{8bc12ef u0 com.android.messaging/.ui.conversationlist.ConversationListActivity t89}

  ResumedActivity: ActivityRecord{8bc12ef u0 com.android.messaging/.ui.conversationlist.ConversationListActivity t89}

说明：
1.在#0的ActivityDisplay上，总共有2个Stack，代表2个应用
2.在Stack #2里面，有一个TaskRecord，Task id #89
3.在TaskRecord里面，Activities列表里面只有一个ActivityRecord

四个类的定义相关介绍

这个我也直接使用其制作的图片：
在这里插入图片描述

四个类的关键变量

ActivityDisplay 类有如下关键变量

/**
 * Exactly one of these classes per Display in the system. Capable of holding zero or more
 * attached {@link ActivityStack}s.
 */
class ActivityDisplay extends ConfigurationContainer<ActivityStack>
        implements WindowContainerListener {
......
DisplayContent mDisplayContent;  // 对应WindowManagerService的显示
/** Actual Display this object tracks. */
int mDisplayId;  // id

/**
 * All of the stacks on this display. Order matters, topmost stack is in front of all other
 * stacks, bottommost behind. Accessed directly by ActivityManager package classes. Any calls
 * changing the list should also call {@link #onStackOrderChanged()}.
 */
 // 当前显示屏上的所有ActivityStack
private final ArrayList<ActivityStack> mStacks = new ArrayList<>();

ActivityStack类有如下关键变量

/**
 * State and management of a single stack of activities.
 */
public class ActivityStack extends ConfigurationContainer {
......
    final int mStackId;  // 唯一ID
    /** The attached Display's unique identifier, or -1 if detached */
    int mDisplayId;  // 所处的显示屏id,如果detach则为-1
    /**
     * The back history of all previous (and possibly still
     * running) activities.  It contains #TaskRecord objects.
     */
    // ActivityStack里面所包含的所有TaskRecord对象
    private final ArrayList<TaskRecord> mTaskHistory = new ArrayList<>();

    TaskStack mTaskStack;  // 对应WindowManagerService里面的

      /**
     * Current activity that is resumed, or null if there is none.
     */
    ActivityRecord mResumedActivity = null; // 当前resume状态的Activity

TaskRecord 类有如下关键变量：

class TaskRecord extends ConfigurationContainer {
......
    final int taskId;       // Unique identifier for this task.
     /** List of all activities in the task arranged in history order */
    final ArrayList<ActivityRecord> mActivities; // 当前Task里面所包含的所有Activity对象
    /** Current stack. Setter must always be used to update the value. */
    private ActivityStack mStack;  // 所属的ActivityStack
    Task mTask; // 对应WindowManagerService里面的

ActivityRecord 类有如下关键变量：

/**
 * An entry in the history stack, representing an activity.
 */
public final class ActivityRecord extends ConfigurationContainer {
......
    final IApplicationToken.Stub appToken; // window manager token
    // TODO: Remove after unification
    AppWindowToken mAppWindowToken; // 继承自WindowToken,代表一种window类型，为应用窗口
    // activity相关的信息
    final ActivityInfo info; // all about me
    
    private TaskRecord task;        // the task this is in.
    // ActivityRecord在初始化的时候会创建Token对象，作为服务端
   static class Token extends IApplicationToken.Stub

ActivityRecord 类中有ActivityInfo 类的变量info：

我们再看一下ActivityInfo 类：

ActivityInfo 类就是表示应用中AndroidManifest.xml配置文件中activity和receiver的配置信息。其关键的变量，我们在其构造方法中可以看到：

/**
 * Information you can retrieve about a particular application
 * activity or receiver. This corresponds to information collected
 * from the AndroidManifest.xml's &lt;activity&gt; and
 * &lt;receiver&gt; tags.
 */
public class ActivityInfo extends ComponentInfo implements Parcelable {
......
    public ActivityInfo(ActivityInfo orig) {
        super(orig);
        theme = orig.theme;
        launchMode = orig.launchMode;
        documentLaunchMode = orig.documentLaunchMode;
        permission = orig.permission;
        taskAffinity = orig.taskAffinity;
        targetActivity = orig.targetActivity;
        flags = orig.flags;
        privateFlags = orig.privateFlags;
        screenOrientation = orig.screenOrientation;
        configChanges = orig.configChanges;
        softInputMode = orig.softInputMode;
        uiOptions = orig.uiOptions;
        parentActivityName = orig.parentActivityName;
        maxRecents = orig.maxRecents;
        lockTaskLaunchMode = orig.lockTaskLaunchMode;
        windowLayout = orig.windowLayout;
        resizeMode = orig.resizeMode;
        mInitResizeMode = orig.mInitResizeMode;
        requestedVrComponent = orig.requestedVrComponent;
        rotationAnimation = orig.rotationAnimation;
        colorMode = orig.colorMode;
        maxAspectRatio = orig.maxAspectRatio;
        minAspectRatio = orig.minAspectRatio;
    }

其ActivityRecord 类的dump信息为：

在这里插入图片描述

四个类如何关联

ActivityRecord创建

在startActivity的过程中，会先new ActivityRecord

ActivityTaskManager: 	at com.android.server.wm.ActivityRecord.setState(ActivityRecord.java:1857)
ActivityTaskManager: 	at com.android.server.wm.ActivityRecord.<init>(ActivityRecord.java:964)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.startActivity(ActivityStarter.java:902)

其具体流程为：
在ActivityStarter.startActivity中：

ActivityRecord r = new ActivityRecord(mService, callerApp, callingPid, callingUid,
        callingPackage, intent, resolvedType, aInfo, mService.getGlobalConfiguration(),
        resultRecord, resultWho, requestCode, componentSpecified, voiceSession != null,
        mSupervisor, checkedOptions, sourceRecord);

在ActivityRecord.，也就是ActivityRecord的构造方法ActivityRecord中：

setState(INITIALIZING, "ActivityRecord ctor");

ActivityStack创建以及和ActivityDisplay的关联

ActivityStack也在是startActivity的过程中创建的

ActivityTaskManager: 	at com.android.server.wm.ActivityStack.<init>(ActivityStack.java:511)
ActivityTaskManager: 	at com.android.server.wm.ActivityDisplay.createStackUnchecked(ActivityDisplay.java:465)
ActivityTaskManager: 	at com.android.server.wm.ActivityDisplay.createStack(ActivityDisplay.java:455)
ActivityTaskManager: 	at com.android.server.wm.ActivityDisplay.getOrCreateStack(ActivityDisplay.java:383)
ActivityTaskManager: 	at com.android.server.wm.ActivityDisplay.getOrCreateStack(ActivityDisplay.java:401)
ActivityTaskManager: 	at com.android.server.wm.RootActivityContainer.getLaunchStack(RootActivityContainer.java:1737)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.getLaunchStack(ActivityStarter.java:2704)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.computeStackFocus(ActivityStarter.java:2612)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.setTaskFromReuseOrCreateNewTask(ActivityStarter.java:2323)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.startActivityUnchecked(ActivityStarter.java:1688)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.startActivity(ActivityStarter.java:1404)

在ActivityStack的构造方法中，会调用ActivityDisplay的addChild方法，

display.addChild(this, onTop ? POSITION_TOP : POSITION_BOTTOM);

其display，就是ActivityDisplay变量，其ActivityDisplay–add方法为：

void addChild(ActivityStack stack, int position) {
    if (position == POSITION_BOTTOM) {
        position = 0;
    } else if (position == POSITION_TOP) {
        position = mStacks.size();
    }
    if (DEBUG_STACK) Slog.v(TAG_STACK, "addChild: attaching " + stack
            + " to displayId=" + mDisplayId + " position=" + position);
    addStackReferenceIfNeeded(stack);
    positionChildAt(stack, position);
    mService.updateSleepIfNeededLocked();
}

将自己加入到ActivityDisplay的mStack里面，mStack定义如下

ArrayList<ActivityStack> mStacks

此时，ActivityDisplay和ActivityStack关联起来

TaskRecord创建以及和ActivityStack的关联

TaskRecord也在是startActivity的过程中创建的

ActivityTaskManager: 	at com.android.server.wm.TaskRecord.create(TaskRecord.java:2704)
ActivityTaskManager: 	at com.android.server.wm.ActivityStack.createTaskRecord(ActivityStack.java:5515)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.setTaskFromReuseOrCreateNewTask(ActivityStarter.java:2330)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.startActivityUnchecked(ActivityStarter.java:1688)

在ActivityStack.createTaskRecord方法里面，调用addTask将TaskRecord和ActivityStack关联起来
ActivityStack.createTaskRecord方法：

TaskRecord createTaskRecord(int taskId, ActivityInfo info, Intent intent,
        IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
        boolean toTop, ActivityRecord activity, ActivityRecord source,
        ActivityOptions options) {
        
    final TaskRecord task = TaskRecord.create(
            mService, taskId, info, intent, voiceSession, voiceInteractor);
            
    // add the task to stack first, mTaskPositioner might need the stack association
    addTask(task, toTop, "createTaskRecord");
......

将task加入 mTaskHistory，其定义如下

private final ArrayList<TaskRecord> mTaskHistory = new ArrayList<>();

其ActivityStack.addTask的方法如下：

// TODO: This shouldn't allow automatic reparenting. Remove the call to preAddTask and deal
// with the fall-out...
void addTask(final TaskRecord task, int position, boolean schedulePictureInPictureModeChange,
        String reason) {
......
    mTaskHistory.add(position, task);

事实上，我们创建TaskRecord的接口在ActivityStarter–setTaskFromReuseOrCreateNewTask方法中：

private int setTaskFromReuseOrCreateNewTask(TaskRecord taskToAffiliate) {
......
    // Do no move the target stack to front yet, as we might bail if
    // isLockTaskModeViolation fails below.

    if (mReuseTask == null) {
        final boolean toTop = !mLaunchTaskBehind && !mAvoidMoveToFront;
        final TaskRecord task = mTargetStack.createTaskRecord(
                mSupervisor.getNextTaskIdForUserLocked(mStartActivity.mUserId),
                mNewTaskInfo != null ? mNewTaskInfo : mStartActivity.info,
                mNewTaskIntent != null ? mNewTaskIntent : mIntent, mVoiceSession,
                mVoiceInteractor, toTop, mStartActivity, mSourceRecord, mOptions);
......

TaskRecord和ActivityRecord的关联

在上面分别创建了ActivityRecord和TaskRecord对象，

ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.addOrReparentStartingActivity(ActivityStarter.java:2574)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.setTaskFromReuseOrCreateNewTask(ActivityStarter.java:2335)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.startActivityUnchecked(ActivityStarter.java:1688)
ActivityTaskManager: 	at com.android.server.wm.ActivityStarter.startActivity(ActivityStarter.java:1404)

在setTaskFromReuseOrCreateNewTask方法里面，先调用createTaskRecord来创建TaskRecord，然后调用addOrReparentStartingActivity来设置Activity与TaskRecord的关系

ActivityStarter–setTaskFromReuseOrCreateNewTask

private int setTaskFromReuseOrCreateNewTask(TaskRecord taskToAffiliate) {
......
    // Do no move the target stack to front yet, as we might bail if
    // isLockTaskModeViolation fails below.

    if (mReuseTask == null) {
        final boolean toTop = !mLaunchTaskBehind && !mAvoidMoveToFront;
        final TaskRecord task = mTargetStack.createTaskRecord(
                mSupervisor.getNextTaskIdForUserLocked(mStartActivity.mUserId),
                mNewTaskInfo != null ? mNewTaskInfo : mStartActivity.info,
                mNewTaskIntent != null ? mNewTaskIntent : mIntent, mVoiceSession,
                mVoiceInteractor, toTop, mStartActivity, mSourceRecord, mOptions);
         addOrReparentStartingActivity(task, "setTaskFromReuseOrCreateNewTask - mReuseTask");
......

ActivityStarter.addOrReparentStartingActivity

private void addOrReparentStartingActivity(TaskRecord parent, String reason) {
        // 如果当前ActivityRecord没有设置TaskRecord或者已经设置过就是给定的parent,则添加到mActivities列表里面
        if (mStartActivity.getTaskRecord() == null || mStartActivity.getTaskRecord() == parent) {
            parent.addActivityToTop(mStartActivity); // 会调用r.setTask(this)设置关联关系
        } else {
            // 将当前要启动的Activity重新关联到给定的parent 上
            mStartActivity.reparent(parent, parent.mActivities.size() /* top */, reason);
        }
 }

其mStartActivity变量为：：

 // Share state variable among methods when starting an activity.
 private ActivityRecord mStartActivity;

其parent变量为：

TaskRecord parent

activity和window的关系

关于Task管理一个简单对应关系:

在这里插入图片描述
从整体界面的关系来看：

参考资料

(1)android里面的Activity体系结构(1)_ActivityDisplay/ActivityStack/TaskRecord/ActivityRecord
https://blog.youkuaiyun.com/weixin_42695485/article/details/108680240
(2)ActivityRecord、TaskRecord、ActivityStack、ActivityDisplay、ActivityStackSupervisor到底是干嘛的？
https://blog.youkuaiyun.com/jiejingguo/article/details/100188576?utm_medium=distribute.pc_relevant.none-task-blog-OPENSEARCH-1.control&depth_1-utm_source=distribute.pc_relevant.none-task-blog-OPENSEARCH-1.control
(3)Activity 启动流程log分析
https://blog.youkuaiyun.com/weixin_42695485/article/details/108632021
(4)android window和activity一些理解
https://blog.youkuaiyun.com/weixin_42695485/article/details/108876562