Launcher3启动

Launcher3启动

startOtherServices

//frameworks/base/services/java/com/android/server/SystemServer.java
private void startOtherServices(@NonNull TimingsTraceAndSlog t) {
		mActivityManagerService.systemReady(() -> {
		           Slog.i(TAG, "Making services ready");
		           t.traceBegin("StartActivityManagerReadyPhase");
		           mSystemServiceManager.startBootPhase(t, SystemService.PHASE_ACTIVITY_MANAGER_READY);
		           t.traceEnd();
		           t.traceBegin("StartObservingNativeCrashes");
		           try {
		               mActivityManagerService.startObservingNativeCrashes();
		           } catch (Throwable e) {
		               reportWtf("observing native crashes", e);
		           }
		           t.traceEnd();
		
		           t.traceBegin("RegisterAppOpsPolicy");
		           try {
		               mActivityManagerService.setAppOpsPolicy(new AppOpsPolicy(mSystemContext));
		           } catch (Throwable e) {
		               reportWtf("registering app ops policy", e);
		           }
		           t.traceEnd();
		
		           // No dependency on Webview preparation in system server. But this should
		           // be completed before allowing 3rd party
		           final String WEBVIEW_PREPARATION = "WebViewFactoryPreparation";
		           Future<?> webviewPrep = null;
		           if (mWebViewUpdateService != null) {
		               webviewPrep = SystemServerInitThreadPool.submit(() -> {
		                   Slog.i(TAG, WEBVIEW_PREPARATION);
		                   TimingsTraceAndSlog traceLog = TimingsTraceAndSlog.newAsyncLog();
		                   traceLog.traceBegin(WEBVIEW_PREPARATION);
		                   ConcurrentUtils.waitForFutureNoInterrupt(mZygotePreload, "Zygote preload");
		                   mZygotePreload = null;
		                   mWebViewUpdateService.prepareWebViewInSystemServer();
		                   traceLog.traceEnd();
		               }, WEBVIEW_PREPARATION);
		           }
}

systemReady（）

//frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java
mAtmInternal = LocalServices.getService(ActivityTaskManagerInternal.class);
	 ......
public void systemReady(final Runnable goingCallback, @NonNull TimingsTraceAndSlog t) {
	 ......
      if (isBootingSystemUser && !UserManager.isHeadlessSystemUserMode()) {
         t.traceBegin("startHomeOnAllDisplays");
          mAtmInternal.startHomeOnAllDisplays(currentUserId, "systemReady");
          t.traceEnd();
      }
      .......
}

startHomeOnAllDisplays()

//frameworks/base/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
    public void setWindowManager(WindowManagerService wm) {
        synchronized (mGlobalLock) {
            mWindowManager = wm;
            mRootWindowContainer = wm.mRoot;
            ......
        }
    }

    @Override
    public boolean startHomeOnAllDisplays(int userId, String reason) {
        synchronized (mGlobalLock) {
            return mRootWindowContainer.startHomeOnAllDisplays(userId, reason);
        }
    }

startHomeOnAllDisplays(

//frameworks/base/services/core/java/com/android/server/wm/RootWindowContainer.java
    boolean startHomeOnAllDisplays(int userId, String reason) {
        boolean homeStarted = false;
        for (int i = getChildCount() - 1; i >= 0; i--) {
            final int displayId = getChildAt(i).mDisplayId;
            homeStarted |= startHomeOnDisplay(userId, reason, displayId);
        }
        return homeStarted;
    }