Android P WMS初始化过程
Android P WMS简介
Android P WMS初始化过程
Android P WMS addwindow流程
Android P WMS removewindow流程
Android P WMS relayoutWindow流程
Android P WMS windowanimator
Android P WMS Surface
Android P WMS 问题种类和debug分析技巧
Android P WMS View System 简介
Android P WMS初始化过程
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@/frameworks/base/services/java/com/android/server/SystemServer.
java
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private
void
startOtherServices
() {
-
WindowManagerService wm =
null;
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InputManagerService inputManager =
null;
-
-
traceBeginAndSlog(
"InitWatchdog");
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final Watchdog watchdog = Watchdog.getInstance();
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watchdog.init(context, mActivityManagerService);
-
traceEnd();
-
-
traceBeginAndSlog(
"StartInputManagerService");
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inputManager =
new InputManagerService(context);
//4 需要input，因此才有事件输入
-
traceEnd();
-
-
traceBeginAndSlog(
"StartWindowManagerService");
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// WMS needs sensor service ready
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ConcurrentUtils.waitForFutureNoInterrupt(mSensorServiceStart, START_SENSOR_SERVICE);
-
mSensorServiceStart =
null;
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wm = WindowManagerService.main(context, inputManager,
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mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL,
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!mFirstBoot, mOnlyCore,
new PhoneWindowManager());
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ServiceManager.addService(Context.WINDOW_SERVICE, wm,
/* allowIsolated= */
false,
-
DUMP_FLAG_PRIORITY_CRITICAL | DUMP_FLAG_PROTO);
-
ServiceManager.addService(Context.INPUT_SERVICE, inputManager,
-
/* allowIsolated= */
false, DUMP_FLAG_PRIORITY_CRITICAL);
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traceEnd();
-
-
traceBeginAndSlog(
"SetWindowManagerService");
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mActivityManagerService.setWindowManager(wm);
-
traceEnd();
-
-
traceBeginAndSlog(
"WindowManagerServiceOnInitReady");
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wm.onInitReady();
//android o没有
-
traceEnd();
-
-
-
traceBeginAndSlog(
"StartInputManager");
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inputManager.setWindowManagerCallbacks(wm.getInputMonitor());
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inputManager.start();
-
traceEnd();
-
-
// TODO: Use service dependencies instead.
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traceBeginAndSlog(
"DisplayManagerWindowManagerAndInputReady");
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mDisplayManagerService.windowManagerAndInputReady();
-
traceEnd();
-
-
-
traceBeginAndSlog(
"MakeWindowManagerServiceReady");
-
try {
-
wm.systemReady();
-
}
catch (Throwable e) {
-
reportWtf(
"making Window Manager Service ready", e);
-
}
-
traceEnd();
-
-
-
// Update the configuration for this context by hand, because we're going
-
// to start using it before the config change done in wm.systemReady() will
-
// propagate to it.
-
final Configuration config = wm.computeNewConfiguration(DEFAULT_DISPLAY);
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DisplayMetrics metrics =
new DisplayMetrics();
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WindowManager w = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
-
w.getDefaultDisplay().getMetrics(metrics);
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context.getResources().updateConfiguration(config, metrics);
-
-
}
startOtherServices方法用于启动其他服务，其他服务大概有70多个，上面的代码只列出了WMS以及和它相关的IMS的启动逻辑，剩余的其他服务的启动逻辑也都大同小异。
在注释1、2处分别得到Watchdog实例并对它进行初始化，Watchdog用来监控系统的一些关键服务的运行状况，后文会再次提到它。在注释3处创建了IMS，并赋值给IMS类型的inputManager对象。注释4处执行了WMS的main方法，其内部会创建WMS，需要注意的是main方法其中一个传入的参数就是注释1处创建的IMS，WMS是输入事件的中转站，其内部包含了IMS引用并不意外。结合上文，我们可以得知WMS的main方法是运行在SystemServer的run方法中，换句话说就是运行在”system_server”线程”中，后面会再次提到”system_server”线程。
注释5和注释6处分别将WMS和IMS注册到ServiceManager中，这样如果某个客户端想要使用WMS，就需要先去ServiceManager中查询信息，然后根据信息与WMS所在的进程建立通信通路，客户端就可以使用WMS了。注释7处用来初始化显示信息，注释8处则用来通知WMS，系统的初始化工作已经完成，其内部调用了WindowManagerPolicy的systemReady方法。
-
@http:
//androidxref.com/9.0.0_r3/xref/frameworks/base/services/java/com/android/server/SystemServer.java#875
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private WindowManagerService(Context context, InputManagerService inputManager,
-
boolean haveInputMethods, boolean showBootMsgs, boolean onlyCore,
-
WindowManagerPolicy policy) {
-
-
mInputManager = inputManager;
// Must be before createDisplayContentLocked.
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mDisplayManagerInternal = LocalServices.getService(DisplayManagerInternal.class);
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mDisplaySettings =
new DisplaySettings();
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mDisplaySettings.readSettingsLocked();
-
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mPolicy = policy;
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mAnimator =
new WindowAnimator(
this);
//创建了WindowAnimator，它用于管理所有的窗口动画
-
mRoot =
new RootWindowContainer(
this);
-
-
mWindowPlacerLocked =
new WindowSurfacePlacer(
this);
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mTaskSnapshotController =
new TaskSnapshotController(
this);
-
-
mWindowTracing = WindowTracing.createDefaultAndStartLooper(context);
-
-
LocalServices.addService(WindowManagerPolicy.class, mPolicy);
-
-
if(mInputManager !=
null) {
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final InputChannel inputChannel = mInputManager.monitorInput(TAG_WM);
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mPointerEventDispatcher = inputChannel !=
null
-
?
new PointerEventDispatcher(inputChannel) :
null;
-
}
else {
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mPointerEventDispatcher =
null;
-
}
-
-
mDisplayManager = (DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);
-
-
mKeyguardDisableHandler =
new KeyguardDisableHandler(mContext, mPolicy);
-
-
...
-
-
//得到AMS实例，并赋值给mActivityManager ，这样WMS就持有了AMS的引用
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mActivityManager = ActivityManager.getService();
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mAmInternal = LocalServices.getService(ActivityManagerInternal.class);
-
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IntentFilter filter =
new IntentFilter();
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// Track changes to DevicePolicyManager state so we can enable/disable keyguard.
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filter.addAction(ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED);
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mContext.registerReceiver(mBroadcastReceiver, filter);
-
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mLatencyTracker = LatencyTracker.getInstance(context);
-
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mSettingsObserver =
new SettingsObserver();
-
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mHoldingScreenWakeLock = mPowerManager.newWakeLock(
-
PowerManager.SCREEN_BRIGHT_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE, TAG_WM);
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mHoldingScreenWakeLock.setReferenceCounted(
false);
-
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mSurfaceAnimationRunner =
new SurfaceAnimationRunner();
-
-
-
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LocalServices.addService(WindowManagerInternal.class,
new LocalService());
-
}
-
-
-
public void onInitReady() {
-
initPolicy();
//初始化了窗口管理策略的接口类WindowManagerPolicy（WMP）
-
-
// Add ourself to the Watchdog monitors.
-
Watchdog.getInstance().addMonitor(
this);
//加入到watchdog
-
-
openSurfaceTransaction();
-
try {
-
createWatermarkInTransaction();
-
}
finally {
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closeSurfaceTransaction(
"createWatermarkInTransaction");
-
}
-
-
showEmulatorDisplayOverlayIfNeeded();
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}
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private void initPolicy() {
-
UiThread.getHandler().runWithScissors(
new Runnable() {
-
@Override
-
public void run() {
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WindowManagerPolicyThread.set(Thread.currentThread(), Looper.myLooper());
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mPolicy.init(mContext, WindowManagerService.
this, WindowManagerService.
this);
-
}
-
},
0);
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}
运行线程状态
initPolicy方法和此前讲的WMS的main方法的实现类似，注释1处执行了WMP的init方法，WMP是一个接口，init方法的具体实现在PhoneWindowManager（PWM）中。PWM的init方法运行在”android.ui”线程中，它的优先级要高于initPolicy方法所在的”android.display”线程，因此”android.display”线程要等PWM的init方法执行完毕后，处于等待状态的”android.display”线程才会被唤醒从而继续执行下面的代码。
在本文中共提到了3个线程，分别是”system_server”、”android.display”和”android.ui”，为了便于理解，下面给出这三个线程之间的关系。
main运行在DisplayThread(android.display),initPolicy运行在UiThread(android.ui)
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//android.display thread
-
public static WindowManagerService main(final Context context, final InputManagerService im,
-
final boolean haveInputMethods, final boolean showBootMsgs, final boolean onlyCore,
-
WindowManagerPolicy policy) {
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DisplayThread.getHandler().runWithScissors(() ->
-
sInstance =
new WindowManagerService(context, im, haveInputMethods, showBootMsgs,
-
onlyCore, policy),
0);
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return sInstance;
-
}
-
-
-
//android.ui thread
-
private void initPolicy() {
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UiThread.getHandler().runWithScissors(
new Runnable() {
-
@Override
-
public void run() {
-
WindowManagerPolicyThread.set(Thread.currentThread(), Looper.myLooper());
-
mPolicy.init(mContext, WindowManagerService.
this, WindowManagerService.
this);
-
}
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},
0);
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}
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//DisplayThread android.display
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/frameworks/base/services/core/java/com/android/server/
-
H A D DisplayThread.java
36
super(
"android.display", Process.THREAD_PRIORITY_DISPLAY +
1,
false
/*allowIo*/);
-
-
//UiThread android.ui
-
/frameworks/base/services/core/java/com/android/server/
-
H A D UiThread.java
36
super(
"android.ui", Process.THREAD_PRIORITY_FOREGROUND,
false
/*allowIo*/);
“system_server”线程中会调用WMS的main方法，main方法中会创建WMS，创建WMS的过程运行在”android.display”线程中，它的优先级更高一些，因此要等创建WMS完毕后才会唤醒处于等待状态的”system_server”线程。
WMS初始化时会执行initPolicy方法，initPolicy方法会调用PWM的init方法，这个init方法运行在”android.ui”线程，并且优先级更高，因此要先执行完PWM的init方法后，才会唤醒处于等待状态的”android.display”线程。
PWM的init方法执行完毕后会接着执行运行在”system_server”线程的代码，比如本文前部分提到WMS的
systemReady方法。
总结
wms初始化和前面的android版本变化不是很大，可以进行对比分析
源码路径： http://androidxref.com/9.0.0_r3/
参考书籍: Android解析WindowManager系列
Android解析WindowManagerService（一）WMS的诞生
《深入理解Android：卷III》