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Commit 3d0bfd95 authored by Wale Ogunwale's avatar Wale Ogunwale
Browse files

Prevent orphaning of windows when token is removed 

When the owner of a window token requests window manager to remove the
token, we were removing it from it's parent which orphaned the token
and all it's windows and prevented them from being accessed from calls
like forAllWindows(). This problem wasn't visible before as the token
windows would still be in the window list, so they can still be accessed
for the exit animation transition which eventually removes them.
We no longer remove tokens from their parent we when are asked to remove
them from the system. We just set WindowToken.setExiting() so the token
can be removed once all its windows are removed at the end of the exit
animation.

Also,
- In AppWindowToken.removeIfPossible() and Task.removeIfPossible(), call
removeImmediately() instead of parent.removeChild() to make sure the
token and its windows are properly clean-up and avoid orphaning if they
aren't.
- Added DisplayContent.reParentWindowToken() for changing the display a
window token is on which is different from DisplayContent.removeWindowToken
which prepares the token and it's windows to be removed from the system.
- Renamed WindowToken.explicit to WindowToken.mPersistOnEmpty which is
what it does.

Fixes: 33098800
Test: bit FrameworksServicesTests:com.android.server.wm.WindowTokenTests
Test: Make sure toast windows don't persist on screen.
Change-Id: I40e0e8832141514b614e79d8e95cd27f24e52366
parent d291683d

services/core/java/com/android/server/wm/AppWindowToken.java

+2 −5
Original line number Diff line number Diff line
@@ -42,7 +42,6 @@ import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM; 
import static com.android.server.wm.WindowManagerService.H.NOTIFY_ACTIVITY_DRAWN;

import static com.android.server.wm.WindowManagerService.H.NOTIFY_STARTING_WINDOW_DRAWN;

import static com.android.server.wm.WindowManagerService.UPDATE_FOCUS_NORMAL;

import static com.android.server.wm.WindowStateAnimator.STACK_CLIP_NONE;

import static com.android.server.wm.WindowManagerService.UPDATE_FOCUS_WILL_PLACE_SURFACES;

import static com.android.server.wm.WindowManagerService.logWithStack;
@@ -62,12 +61,10 @@ import android.util.Slog; 
import android.view.IApplicationToken;

import android.view.View;

import android.view.WindowManager;

import android.view.animation.Animation;



import java.io.PrintWriter;

import java.util.ArrayDeque;

import java.util.ArrayList;

import java.util.function.Function;



class AppTokenList extends ArrayList<AppWindowToken> {

}
@@ -390,10 +387,10 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree 
    @Override

    void removeIfPossible() {

        mIsExiting = false;

        removeAllWindows();

        removeAllWindowsIfPossible();

        if (mTask != null) {

            mTask.mStack.mExitingAppTokens.remove(this);

            mTask.removeChild(this);

            removeImmediately();

        }

    }

services/core/java/com/android/server/wm/DisplayContent.java

+18 −5
Original line number Diff line number Diff line
@@ -300,7 +300,7 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo 
        return token.asAppWindowToken();

    }



    void setWindowToken(IBinder binder, WindowToken token) {

    void addWindowToken(IBinder binder, WindowToken token) {

        final DisplayContent dc = mService.mRoot.getWindowTokenDisplay(token);

        if (dc != null) {

            // We currently don't support adding a window token to the display if the display
@@ -333,20 +333,33 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo 
    WindowToken removeWindowToken(IBinder binder) {

        final WindowToken token = mTokenMap.remove(binder);

        if (token != null && token.asAppWindowToken() == null) {

            token.setExiting();

        }

        return token;

    }



    /** Changes the display the input window token is housed on to this one. */

    void reParentWindowToken(WindowToken token) {

        final DisplayContent prevDc = token.getDisplayContent();

        if (prevDc == this) {

            return;

        }

        if (prevDc != null && prevDc.mTokenMap.remove(token.token) != null) {

            switch (token.windowType) {

                case TYPE_WALLPAPER:

                    mBelowAppWindowsContainers.removeChild(token);

                    prevDc.mBelowAppWindowsContainers.removeChild(token);

                    break;

                case TYPE_INPUT_METHOD:

                case TYPE_INPUT_METHOD_DIALOG:

                    mImeWindowsContainers.removeChild(token);

                    prevDc.mImeWindowsContainers.removeChild(token);

                    break;

                default:

                    mAboveAppWindowsContainers.removeChild(token);

                    prevDc.mAboveAppWindowsContainers.removeChild(token);

                    break;

            }

        }

        return token;



        addWindowToken(token.token, token);

    }



    void removeAppToken(IBinder binder) {

services/core/java/com/android/server/wm/Task.java

+2 −2
Original line number Diff line number Diff line
@@ -146,11 +146,11 @@ class Task extends WindowContainer<AppWindowToken> implements DimLayer.DimLayerU 
        if (content != null) {

            content.mDimLayerController.removeDimLayerUser(this);

        }

        getParent().removeChild(this);

        removeImmediately();

        mService.mTaskIdToTask.delete(mTaskId);

    }



    // Change to use reparenting in WC when TaskStack is switched to use WC.

    // Change to use re-parenting in WC when TaskStack is switched to use WC.

    void moveTaskToStack(TaskStack stack, boolean toTop) {

        if (stack == mStack) {

            return;

services/core/java/com/android/server/wm/WindowManagerService.java

+2 −4
Original line number Diff line number Diff line
@@ -1654,7 +1654,7 @@ public class WindowManagerService extends IWindowManager.Stub 
        if (DEBUG_ADD_REMOVE) Slog.v(TAG_WM, "Removing " + win + " from " + token);

        // Window will already be removed from token before this post clean-up method is called.

        if (token.isEmpty()) {

            if (!token.explicit) {

            if (!token.mPersistOnEmpty) {

                token.removeImmediately();

            } else if (atoken != null) {

                // TODO: Should this be moved into AppWindowToken.removeWindow? Might go away after
@@ -2443,8 +2443,6 @@ public class WindowManagerService extends IWindowManager.Stub 
                    return;

                }



                token.setExiting();



                mInputMonitor.updateInputWindowsLw(true /*force*/);

            }

        } finally {
@@ -8924,7 +8922,7 @@ public class WindowManagerService extends IWindowManager.Stub 
                        return;

                    }



                    token.removeAllWindows();

                    token.removeAllWindowsIfPossible();

                }

                WindowManagerService.this.removeWindowToken(binder, displayId);

            }

services/core/java/com/android/server/wm/WindowToken.java

+11 −25
Original line number Diff line number Diff line
@@ -18,25 +18,18 @@ package com.android.server.wm; 


import java.util.Comparator;

import static android.view.WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER;

import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_KEYGUARD;

import static android.view.WindowManager.LayoutParams.TYPE_APPLICATION_STARTING;



import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_ADD_REMOVE;

import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_FOCUS;

import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_LAYERS;

import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_WALLPAPER_LIGHT;

import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_WINDOW_MOVEMENT;

import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;

import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;

import static com.android.server.wm.WindowManagerService.UPDATE_FOCUS_NORMAL;



import android.os.Bundle;

import android.os.Debug;

import android.os.IBinder;

import android.os.RemoteException;

import android.util.Slog;

import android.view.DisplayInfo;

import android.view.animation.Animation;



import java.io.PrintWriter;
@@ -58,8 +51,8 @@ class WindowToken extends WindowContainer<WindowState> { 
    final int windowType;



    // Set if this token was explicitly added by a client, so should

    // not be removed when all windows are removed.

    final boolean explicit;

    // persist (not be removed) when all windows are removed.

    boolean mPersistOnEmpty;



    // For printing.

    String stringName;
@@ -104,27 +97,28 @@ class WindowToken extends WindowContainer<WindowState> { 
        return isFirstChildWindowGreaterThanSecond(newWindow, existingWindow) ? 1 : -1;

    };



    WindowToken(WindowManagerService service, IBinder _token, int type, boolean _explicit,

    WindowToken(WindowManagerService service, IBinder _token, int type, boolean persistOnEmpty,

            DisplayContent dc) {

        mService = service;

        token = _token;

        windowType = type;

        explicit = _explicit;

        mPersistOnEmpty = persistOnEmpty;

        onDisplayChanged(dc);

    }



    void removeAllWindows() {

    void removeAllWindowsIfPossible() {

        for (int i = mChildren.size() - 1; i >= 0; --i) {

            final WindowState win = mChildren.get(i);

            if (DEBUG_WINDOW_MOVEMENT) Slog.w(TAG_WM, "removeAllWindows: removing win=" + win);

            if (DEBUG_WINDOW_MOVEMENT) Slog.w(TAG_WM,

                    "removeAllWindowsIfPossible: removing win=" + win);

            win.removeIfPossible();

            if (mChildren.contains(win)) {

                removeChild(win);

            }

        }

    }



    void setExiting() {

        // This token is exiting, so allow it to be removed when it no longer contains any windows.

        mPersistOnEmpty = false;



        if (hidden) {

            return;

        }
@@ -297,16 +291,8 @@ class WindowToken extends WindowContainer<WindowState> { 
    }



    void onDisplayChanged(DisplayContent dc) {

        if (mDisplayContent == dc) {

            return;

        }



        if (mDisplayContent != null) {

            mDisplayContent.removeWindowToken(token);

        }

        dc.reParentWindowToken(this);

        mDisplayContent = dc;

        mDisplayContent.setWindowToken(token, this);



        super.onDisplayChanged(dc);

    }