Merge "Fix deadlock between WMGlobal and WMS" into main (fc22d96e) · Commits · e / os / android_frameworks_base

core/java/android/view/WindowManagerGlobal.java

+20 −0

Original line number	Original line	Diff line number	Diff line
	@@ -179,9 +179,29 @@ public final class WindowManagerGlobal {
	}		}
	}		}

			/**
			* Sets {@link com.android.server.wm.WindowManagerService} for the system process.
			* <p>
			* It is needed to prevent possible deadlock. A possible scenario is:
			* In system process, WMS holds {@link com.android.server.wm.WindowManagerGlobalLock} to call
			* {@code WindowManagerGlobal} APIs and wait to lock {@code WindowManagerGlobal} itself
			* (i.e. call {@link #getWindowManagerService()} in the global lock), while
			* another component may lock {@code WindowManagerGlobal} and wait to lock
			* {@link com.android.server.wm.WindowManagerGlobalLock}(i.e call {@link #addView} in the
			* system process, which calls to {@link com.android.server.wm.WindowManagerService} API
			* directly).
			*/
			public static void setWindowManagerServiceForSystemProcess(@NonNull IWindowManager wms) {
			sWindowManagerService = wms;
			}

	@Nullable		@Nullable
	@UnsupportedAppUsage		@UnsupportedAppUsage
	public static IWindowManager getWindowManagerService() {		public static IWindowManager getWindowManagerService() {
			if (sWindowManagerService != null) {
			// Use WMS directly without locking WMGlobal to prevent deadlock.
			return sWindowManagerService;
			}
	synchronized (WindowManagerGlobal.class) {		synchronized (WindowManagerGlobal.class) {
	if (sWindowManagerService == null) {		if (sWindowManagerService == null) {
	sWindowManagerService = IWindowManager.Stub.asInterface(		sWindowManagerService = IWindowManager.Stub.asInterface(

+5 −2

Original line number	Original line	Diff line number	Diff line
	@@ -1114,8 +1114,11 @@ public class WindowManagerService extends IWindowManager.Stub
	public static WindowManagerService main(final Context context, final InputManagerService im,		public static WindowManagerService main(final Context context, final InputManagerService im,
	final boolean showBootMsgs, WindowManagerPolicy policy,		final boolean showBootMsgs, WindowManagerPolicy policy,
	ActivityTaskManagerService atm) {		ActivityTaskManagerService atm) {
	return main(context, im, showBootMsgs, policy, atm, new DisplayWindowSettingsProvider(),		final WindowManagerService wms = main(context, im, showBootMsgs, policy, atm,
	SurfaceControl.Transaction::new, SurfaceControl.Builder::new);		new DisplayWindowSettingsProvider(), SurfaceControl.Transaction::new,
			SurfaceControl.Builder::new);
			WindowManagerGlobal.setWindowManagerServiceForSystemProcess(wms);
			return wms;
	}		}

	/**		/**