[BadTokenException] Unable to add window token android.os.BinderProxy@8c38b69 is not valid

0x01. 堆栈信息

"---android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@8c38b69 is not valid; is your activity running?
android.view.ViewRootImpl.setView(ViewRootImpl.java:579)
android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:313)
android.view.WindowManagerImpl.addView(WindowManagerImpl.java:86)
android.app.Dialog.show(Dialog.java:322)
com.jd.xxx.xxx.xxx.activity.XxxActivity$4.run(xxxActivity.java:607)
android.os.Handler.handleCallback(Handler.java:742)
android.os.Handler.dispatchMessage(Handler.java:95)
android.os.Looper.loop(Looper.java:154)
android.app.ActivityThread.main(ActivityThread.java:5524)
java.lang.reflect.Method.invoke(Native Method)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)"

0x02. 源码

➜  android-7.0.0_r1 find . -name ViewRootImpl.java
./frameworks/base/core/java/android/view/ViewRootImpl.java

    /**
     * We have one child
     */
    public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {
        synchronized (this) {
            if (mView == null) {
                mView = view;

                mAttachInfo.mDisplayState = mDisplay.getState();
                mDisplayManager.registerDisplayListener(mDisplayListener, mHandler);

                mViewLayoutDirectionInitial = mView.getRawLayoutDirection();
                mFallbackEventHandler.setView(view);
                mWindowAttributes.copyFrom(attrs);
                if (mWindowAttributes.packageName == null) {
                    mWindowAttributes.packageName = mBasePackageName;
                }
                attrs = mWindowAttributes;
                setTag();

                if (DEBUG_KEEP_SCREEN_ON && (mClientWindowLayoutFlags
                        & WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) != 0
                        && (attrs.flags&WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) == 0) {
                    Slog.d(mTag, "setView: FLAG_KEEP_SCREEN_ON changed from true to false!");
                }
                // Keep track of the actual window flags supplied by the client.
                mClientWindowLayoutFlags = attrs.flags;

                setAccessibilityFocus(null, null);

                if (view instanceof RootViewSurfaceTaker) {
                    mSurfaceHolderCallback =
                            ((RootViewSurfaceTaker)view).willYouTakeTheSurface();
                    if (mSurfaceHolderCallback != null) {
                        mSurfaceHolder = new TakenSurfaceHolder();
                        mSurfaceHolder.setFormat(PixelFormat.UNKNOWN);
                    }
                }

                // Compute surface insets required to draw at specified Z value.
                // TODO: Use real shadow insets for a constant max Z.
                if (!attrs.hasManualSurfaceInsets) {
                    attrs.setSurfaceInsets(view, false /*manual*/, true /*preservePrevious*/);
                }

                CompatibilityInfo compatibilityInfo =
                        mDisplay.getDisplayAdjustments().getCompatibilityInfo();
                mTranslator = compatibilityInfo.getTranslator();

                // If the application owns the surface, don't enable hardware acceleration
                if (mSurfaceHolder == null) {
                    enableHardwareAcceleration(attrs);
                }

                boolean restore = false;
                if (mTranslator != null) {
                    mSurface.setCompatibilityTranslator(mTranslator);
                    restore = true;
                    attrs.backup();
                    mTranslator.translateWindowLayout(attrs);
                }
                if (DEBUG_LAYOUT) Log.d(mTag, "WindowLayout in setView:" + attrs);

                if (!compatibilityInfo.supportsScreen()) {
                    attrs.privateFlags |= WindowManager.LayoutParams.PRIVATE_FLAG_COMPATIBLE_WINDOW;
                    mLastInCompatMode = true;
                }

                mSoftInputMode = attrs.softInputMode;
                mWindowAttributesChanged = true;
                mWindowAttributesChangesFlag = WindowManager.LayoutParams.EVERYTHING_CHANGED;
                mAttachInfo.mRootView = view;
                mAttachInfo.mScalingRequired = mTranslator != null;
                mAttachInfo.mApplicationScale =
                        mTranslator == null ? 1.0f : mTranslator.applicationScale;
                if (panelParentView != null) {
                    mAttachInfo.mPanelParentWindowToken
                            = panelParentView.getApplicationWindowToken(); //获取父view的token
                }
                mAdded = true;
                int res; /* = WindowManagerImpl.ADD_OKAY; */ //声明res

                // Schedule the first layout -before- adding to the window
                // manager, to make sure we do the relayout before receiving
                // any other events from the system.
                requestLayout();
                if ((mWindowAttributes.inputFeatures
                        & WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0) {
                    mInputChannel = new InputChannel();
                }
                mForceDecorViewVisibility = (mWindowAttributes.privateFlags
                        & PRIVATE_FLAG_FORCE_DECOR_VIEW_VISIBILITY) != 0;
                try {
                    mOrigWindowType = mWindowAttributes.type;
                    mAttachInfo.mRecomputeGlobalAttributes = true;
                    collectViewAttributes();
                    res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,   //给res赋值, IWindowSession通过调用AIDL接口访问session.
                            getHostVisibility(), mDisplay.getDisplayId(),
                            mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
                            mAttachInfo.mOutsets, mInputChannel);
                } catch (RemoteException e) {
                    mAdded = false;
                    mView = null;
                    mAttachInfo.mRootView = null;
                    mInputChannel = null;
                    mFallbackEventHandler.setView(null);
                    unscheduleTraversals();
                    setAccessibilityFocus(null, null);
                    throw new RuntimeException("Adding window failed", e);
                } finally {
                    if (restore) {
                        attrs.restore();
                    }
                }

                if (mTranslator != null) {
                    mTranslator.translateRectInScreenToAppWindow(mAttachInfo.mContentInsets);
                }
                mPendingOverscanInsets.set(0, 0, 0, 0);
                mPendingContentInsets.set(mAttachInfo.mContentInsets);
                mPendingStableInsets.set(mAttachInfo.mStableInsets);
                mPendingVisibleInsets.set(0, 0, 0, 0);
                mAttachInfo.mAlwaysConsumeNavBar =
                        (res & WindowManagerGlobal.ADD_FLAG_ALWAYS_CONSUME_NAV_BAR) != 0;
                mPendingAlwaysConsumeNavBar = mAttachInfo.mAlwaysConsumeNavBar;
                if (DEBUG_LAYOUT) Log.v(mTag, "Added window " + mWindow);
                if (res < WindowManagerGlobal.ADD_OKAY) {
                    mAttachInfo.mRootView = null;
                    mAdded = false;
                    mFallbackEventHandler.setView(null);
                    unscheduleTraversals();
                    setAccessibilityFocus(null, null);
                    switch (res) {
                        case WindowManagerGlobal.ADD_BAD_APP_TOKEN:
                        case WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- token " + attrs.token
                                    + " is not valid; is your activity running?"); //异常触发位置
                        case WindowManagerGlobal.ADD_NOT_APP_TOKEN:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- token " + attrs.token
                                    + " is not for an application");
                        case WindowManagerGlobal.ADD_APP_EXITING:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- app for token " + attrs.token
                                    + " is exiting");
                        case WindowManagerGlobal.ADD_DUPLICATE_ADD:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- window " + mWindow
                                    + " has already been added");
                        case WindowManagerGlobal.ADD_STARTING_NOT_NEEDED:
                            // Silently ignore -- we would have just removed it
                            // right away, anyway.
                            return;
                        case WindowManagerGlobal.ADD_MULTIPLE_SINGLETON:
                            throw new WindowManager.BadTokenException("Unable to add window "
                                    + mWindow + " -- another window of type "
                                    + mWindowAttributes.type + " already exists");
                        case WindowManagerGlobal.ADD_PERMISSION_DENIED:
                            throw new WindowManager.BadTokenException("Unable to add window "
                                    + mWindow + " -- permission denied for window type "
                                    + mWindowAttributes.type);
                        case WindowManagerGlobal.ADD_INVALID_DISPLAY:
                            throw new WindowManager.InvalidDisplayException("Unable to add window "
                                    + mWindow + " -- the specified display can not be found");
                        case WindowManagerGlobal.ADD_INVALID_TYPE:
                            throw new WindowManager.InvalidDisplayException("Unable to add window "
                                    + mWindow + " -- the specified window type "
                                    + mWindowAttributes.type + " is not valid");
                    }
                    throw new RuntimeException(
                            "Unable to add window -- unknown error code " + res);
                }

                if (view instanceof RootViewSurfaceTaker) {
                    mInputQueueCallback =
                        ((RootViewSurfaceTaker)view).willYouTakeTheInputQueue();
                }
                if (mInputChannel != null) {
                    if (mInputQueueCallback != null) {
                        mInputQueue = new InputQueue();
                        mInputQueueCallback.onInputQueueCreated(mInputQueue);
                    }
                    mInputEventReceiver = new WindowInputEventReceiver(mInputChannel,
                            Looper.myLooper());
                }

                view.assignParent(this);
                mAddedTouchMode = (res & WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE) != 0;
                mAppVisible = (res & WindowManagerGlobal.ADD_FLAG_APP_VISIBLE) != 0;

                if (mAccessibilityManager.isEnabled()) {
                    mAccessibilityInteractionConnectionManager.ensureConnection();
                }

                if (view.getImportantForAccessibility() == View.IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
                    view.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
                }

                // Set up the input pipeline.
                CharSequence counterSuffix = attrs.getTitle();
                mSyntheticInputStage = new SyntheticInputStage();
                InputStage viewPostImeStage = new ViewPostImeInputStage(mSyntheticInputStage);
                InputStage nativePostImeStage = new NativePostImeInputStage(viewPostImeStage,
                        "aq:native-post-ime:" + counterSuffix);
                InputStage earlyPostImeStage = new EarlyPostImeInputStage(nativePostImeStage);
                InputStage imeStage = new ImeInputStage(earlyPostImeStage,
                        "aq:ime:" + counterSuffix);
                InputStage viewPreImeStage = new ViewPreImeInputStage(imeStage);
                InputStage nativePreImeStage = new NativePreImeInputStage(viewPreImeStage,
                        "aq:native-pre-ime:" + counterSuffix);

                mFirstInputStage = nativePreImeStage;
                mFirstPostImeInputStage = earlyPostImeStage;
                mPendingInputEventQueueLengthCounterName = "aq:pending:" + counterSuffix;
            }
        }
    }

frameworks/base/core/java/android/view/IWindowSession.aidl
frameworks/base/services/core/java/com/android/server/wm/Session.java

    @Override
    public int addToDisplay(IWindow window, int seq, WindowManager.LayoutParams attrs,
            int viewVisibility, int displayId, Rect outContentInsets, Rect outStableInsets,
            Rect outOutsets, InputChannel outInputChannel) {
        return mService.addWindow(this, window, seq, attrs, viewVisibility, displayId,
                outContentInsets, outStableInsets, outOutsets, outInputChannel);
    }

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

    public int addWindow(Session session, IWindow client, int seq,
            WindowManager.LayoutParams attrs, int viewVisibility, int displayId,
            Rect outContentInsets, Rect outStableInsets, Rect outOutsets,
            InputChannel outInputChannel) {
        int[] appOp = new int[1];
        int res = mPolicy.checkAddPermission(attrs, appOp);
        if (res != WindowManagerGlobal.ADD_OKAY) {
            return res;
        }

        boolean reportNewConfig = false;
        WindowState attachedWindow = null;
        long origId;
        final int type = attrs.type;

        synchronized(mWindowMap) {
            if (!mDisplayReady) {
                throw new IllegalStateException("Display has not been initialialized");
            }

            final DisplayContent displayContent = getDisplayContentLocked(displayId);
            if (displayContent == null) {
                Slog.w(TAG_WM, "Attempted to add window to a display that does not exist: "
                        + displayId + ".  Aborting.");
                return WindowManagerGlobal.ADD_INVALID_DISPLAY;
            }
            if (!displayContent.hasAccess(session.mUid)) {
                Slog.w(TAG_WM, "Attempted to add window to a display for which the application "
                        + "does not have access: " + displayId + ".  Aborting.");
                return WindowManagerGlobal.ADD_INVALID_DISPLAY;
            }

            if (mWindowMap.containsKey(client.asBinder())) {
                Slog.w(TAG_WM, "Window " + client + " is already added");
                return WindowManagerGlobal.ADD_DUPLICATE_ADD;
            }
        //检查父窗口是否存在,父窗口不存在则抛出异常
            if (type >= FIRST_SUB_WINDOW && type <= LAST_SUB_WINDOW) {
                attachedWindow = windowForClientLocked(null, attrs.token, false);
                if (attachedWindow == null) {
                    Slog.w(TAG_WM, "Attempted to add window with token that is not a window: "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
                }
                if (attachedWindow.mAttrs.type >= FIRST_SUB_WINDOW
                        && attachedWindow.mAttrs.type <= LAST_SUB_WINDOW) {
                    Slog.w(TAG_WM, "Attempted to add window with token that is a sub-window: "
                            + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
                }
            }

            if (type == TYPE_PRIVATE_PRESENTATION && !displayContent.isPrivate()) {
                Slog.w(TAG_WM, "Attempted to add private presentation window to a non-private display.  Aborting.");
                return WindowManagerGlobal.ADD_PERMISSION_DENIED;
            }

            boolean addToken = false;
            WindowToken token = mTokenMap.get(attrs.token);//获取token
            AppWindowToken atoken = null;
            if (token == null) {
                if (type >= FIRST_APPLICATION_WINDOW && type <= LAST_APPLICATION_WINDOW) {
                    Slog.w(TAG_WM, "Attempted to add application window with unknown token "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                if (type == TYPE_INPUT_METHOD) {
                    Slog.w(TAG_WM, "Attempted to add input method window with unknown token "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                if (type == TYPE_VOICE_INTERACTION) {
                    Slog.w(TAG_WM, "Attempted to add voice interaction window with unknown token "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                if (type == TYPE_WALLPAPER) {
                    Slog.w(TAG_WM, "Attempted to add wallpaper window with unknown token "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                if (type == TYPE_DREAM) {
                    Slog.w(TAG_WM, "Attempted to add Dream window with unknown token "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                if (type == TYPE_QS_DIALOG) {
                    Slog.w(TAG_WM, "Attempted to add QS dialog window with unknown token "
                          + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                if (type == TYPE_ACCESSIBILITY_OVERLAY) {
                    Slog.w(TAG_WM, "Attempted to add Accessibility overlay window with unknown token "
                            + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
                token = new WindowToken(this, attrs.token, -1, false);
                addToken = true;
            } else if (type >= FIRST_APPLICATION_WINDOW && type <= LAST_APPLICATION_WINDOW) {
                atoken = token.appWindowToken;
                if (atoken == null) {
                    Slog.w(TAG_WM, "Attempted to add window with non-application token "
                          + token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_NOT_APP_TOKEN;
                } else if (atoken.removed) {
                    Slog.w(TAG_WM, "Attempted to add window with exiting application token "
                          + token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_APP_EXITING;
                }
                if (type == TYPE_APPLICATION_STARTING && atoken.firstWindowDrawn) {
                    // No need for this guy!
                    if (DEBUG_STARTING_WINDOW || localLOGV) Slog.v(
                            TAG_WM, "**** NO NEED TO START: " + attrs.getTitle());
                    return WindowManagerGlobal.ADD_STARTING_NOT_NEEDED;
                }
            } else if (type == TYPE_INPUT_METHOD) {
                if (token.windowType != TYPE_INPUT_METHOD) {
                    Slog.w(TAG_WM, "Attempted to add input method window with bad token "
                            + attrs.token + ".  Aborting.");
                      return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
            } else if (type == TYPE_VOICE_INTERACTION) {
                if (token.windowType != TYPE_VOICE_INTERACTION) {
                    Slog.w(TAG_WM, "Attempted to add voice interaction window with bad token "
                            + attrs.token + ".  Aborting.");
                      return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
            } else if (type == TYPE_WALLPAPER) {
                if (token.windowType != TYPE_WALLPAPER) {
                    Slog.w(TAG_WM, "Attempted to add wallpaper window with bad token "
                            + attrs.token + ".  Aborting.");
                      return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
            } else if (type == TYPE_DREAM) {
                if (token.windowType != TYPE_DREAM) {
                    Slog.w(TAG_WM, "Attempted to add Dream window with bad token "
                            + attrs.token + ".  Aborting.");
                      return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
            } else if (type == TYPE_ACCESSIBILITY_OVERLAY) {
                if (token.windowType != TYPE_ACCESSIBILITY_OVERLAY) {
                    Slog.w(TAG_WM, "Attempted to add Accessibility overlay window with bad token "
                            + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
            } else if (type == TYPE_QS_DIALOG) {  
                if (token.windowType != TYPE_QS_DIALOG) {
                    Slog.w(TAG_WM, "Attempted to add QS dialog window with bad token "
                            + attrs.token + ".  Aborting.");
                    return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                }
            } else if (token.appWindowToken != null) {
                Slog.w(TAG_WM, "Non-null appWindowToken for system window of type=" + type);
                // It is not valid to use an app token with other system types; we will
                // instead make a new token for it (as if null had been passed in for the token).
                attrs.token = null;
                token = new WindowToken(this, null, -1, false);
                addToken = true;
            }

            WindowState win = new WindowState(this, session, client, token,
                    attachedWindow, appOp[0], seq, attrs, viewVisibility, displayContent);
            if (win.mDeathRecipient == null) {
                // Client has apparently died, so there is no reason to
                // continue.
                Slog.w(TAG_WM, "Adding window client " + client.asBinder()
                        + " that is dead, aborting.");
                return WindowManagerGlobal.ADD_APP_EXITING;
            }

            if (win.getDisplayContent() == null) {
                Slog.w(TAG_WM, "Adding window to Display that has been removed.");
                return WindowManagerGlobal.ADD_INVALID_DISPLAY;
            }

            mPolicy.adjustWindowParamsLw(win.mAttrs);
            win.setShowToOwnerOnlyLocked(mPolicy.checkShowToOwnerOnly(attrs));

            res = mPolicy.prepareAddWindowLw(win, attrs); // final WindowManagerPolicy mPolicy = new PhoneWindowManager(); //该场景不会走到这里面
            if (res != WindowManagerGlobal.ADD_OKAY) {
                return res;
            }

            final boolean openInputChannels = (outInputChannel != null
                    && (attrs.inputFeatures & INPUT_FEATURE_NO_INPUT_CHANNEL) == 0);
            if  (openInputChannels) {
                win.openInputChannel(outInputChannel);
            }

            // From now on, no exceptions or errors allowed!

            res = WindowManagerGlobal.ADD_OKAY;

            if (excludeWindowTypeFromTapOutTask(type)) {
                displayContent.mTapExcludedWindows.add(win);
            }

            origId = Binder.clearCallingIdentity();

            if (addToken) {
                mTokenMap.put(attrs.token, token); //缓存token
            }
            win.attach();
            mWindowMap.put(client.asBinder(), win);
            if (win.mAppOp != AppOpsManager.OP_NONE) {
                int startOpResult = mAppOps.startOpNoThrow(win.mAppOp, win.getOwningUid(),
                        win.getOwningPackage());
                if ((startOpResult != AppOpsManager.MODE_ALLOWED) &&
                        (startOpResult != AppOpsManager.MODE_DEFAULT)) {
                    win.setAppOpVisibilityLw(false);
                }
            }

            if (type == TYPE_APPLICATION_STARTING && token.appWindowToken != null) {
                token.appWindowToken.startingWindow = win;
                if (DEBUG_STARTING_WINDOW) Slog.v (TAG_WM, "addWindow: " + token.appWindowToken
                        + " startingWindow=" + win);
            }

            boolean imMayMove = true;

            if (type == TYPE_INPUT_METHOD) {
                win.mGivenInsetsPending = true;
                mInputMethodWindow = win;
                addInputMethodWindowToListLocked(win);
                imMayMove = false;
            } else if (type == TYPE_INPUT_METHOD_DIALOG) {
                mInputMethodDialogs.add(win);
                addWindowToListInOrderLocked(win, true);
                moveInputMethodDialogsLocked(findDesiredInputMethodWindowIndexLocked(true));
                imMayMove = false;
            } else {
                addWindowToListInOrderLocked(win, true);
                if (type == TYPE_WALLPAPER) {
                    mWallpaperControllerLocked.clearLastWallpaperTimeoutTime();
                    displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
                } else if ((attrs.flags&FLAG_SHOW_WALLPAPER) != 0) {
                    displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
                } else if (mWallpaperControllerLocked.isBelowWallpaperTarget(win)) {
                    // If there is currently a wallpaper being shown, and
                    // the base layer of the new window is below the current
                    // layer of the target window, then adjust the wallpaper.
                    // This is to avoid a new window being placed between the
                    // wallpaper and its target.
                    displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
                }
            }

            // If the window is being added to a task that's docked but non-resizeable,
            // we need to update this new window's scroll position when it's added.
            win.applyScrollIfNeeded();

            // If the window is being added to a stack that's currently adjusted for IME,
            // make sure to apply the same adjust to this new window.
            win.applyAdjustForImeIfNeeded();

            if (type == TYPE_DOCK_DIVIDER) {
                getDefaultDisplayContentLocked().getDockedDividerController().setWindow(win);
            }

            final WindowStateAnimator winAnimator = win.mWinAnimator;
            winAnimator.mEnterAnimationPending = true;
            winAnimator.mEnteringAnimation = true;
            // Check if we need to prepare a transition for replacing window first.
            if (atoken != null && !prepareWindowReplacementTransition(atoken)) {
                // If not, check if need to set up a dummy transition during display freeze
                // so that the unfreeze wait for the apps to draw. This might be needed if
                // the app is relaunching.
                prepareNoneTransitionForRelaunching(atoken);
            }

            if (displayContent.isDefaultDisplay) {
                final DisplayInfo displayInfo = displayContent.getDisplayInfo();
                final Rect taskBounds;
                if (atoken != null && atoken.mTask != null) {
                    taskBounds = mTmpRect;
                    atoken.mTask.getBounds(mTmpRect);
                } else {
                    taskBounds = null;
                }
                if (mPolicy.getInsetHintLw(win.mAttrs, taskBounds, mRotation,
                        displayInfo.logicalWidth, displayInfo.logicalHeight, outContentInsets,
                        outStableInsets, outOutsets)) {
                    res |= WindowManagerGlobal.ADD_FLAG_ALWAYS_CONSUME_NAV_BAR;
                }
            } else {
                outContentInsets.setEmpty();
                outStableInsets.setEmpty();
            }

            if (mInTouchMode) {
                res |= WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE;
            }
            if (win.mAppToken == null || !win.mAppToken.clientHidden) {
                res |= WindowManagerGlobal.ADD_FLAG_APP_VISIBLE;
            }

            mInputMonitor.setUpdateInputWindowsNeededLw();

            boolean focusChanged = false;
            if (win.canReceiveKeys()) {
                focusChanged = updateFocusedWindowLocked(UPDATE_FOCUS_WILL_ASSIGN_LAYERS,
                        false /*updateInputWindows*/);
                if (focusChanged) {
                    imMayMove = false;
                }
            }

            if (imMayMove) {
                moveInputMethodWindowsIfNeededLocked(false);
            }

            mLayersController.assignLayersLocked(displayContent.getWindowList());
            // Don't do layout here, the window must call
            // relayout to be displayed, so we'll do it there.

            if (focusChanged) {
                mInputMonitor.setInputFocusLw(mCurrentFocus, false /*updateInputWindows*/);
            }
            mInputMonitor.updateInputWindowsLw(false /*force*/);

            if (localLOGV || DEBUG_ADD_REMOVE) Slog.v(TAG_WM, "addWindow: New client "
                    + client.asBinder() + ": window=" + win + " Callers=" + Debug.getCallers(5));

            if (win.isVisibleOrAdding() && updateOrientationFromAppTokensLocked(false)) {
                reportNewConfig = true;
            }
            if (attrs.removeTimeoutMilliseconds > 0) {
                mH.sendMessageDelayed(
                        mH.obtainMessage(H.WINDOW_REMOVE_TIMEOUT, win),
                        attrs.removeTimeoutMilliseconds);
            }
        }

        if (reportNewConfig) {
            sendNewConfiguration();
        }

        Binder.restoreCallingIdentity(origId);

        return res;
    }

frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java

    /**
     * Preflight adding a window to the system.
     *
     * Currently enforces that three window types are singletons:
     * 

     * 
STATUS_BAR_TYPE
     * 
KEYGUARD_TYPE
     * 
     *
     * @param win The window to be added
     * @param attrs Information about the window to be added
     *
     * @return If ok, WindowManagerImpl.ADD_OKAY.  If too many singletons,
     * WindowManagerImpl.ADD_MULTIPLE_SINGLETON
     */
    @Override
    public int prepareAddWindowLw(WindowState win, WindowManager.LayoutParams attrs) {
        switch (attrs.type) {
            case TYPE_STATUS_BAR:
                mContext.enforceCallingOrSelfPermission(
                        android.Manifest.permission.STATUS_BAR_SERVICE,
                        "PhoneWindowManager");
                if (mStatusBar != null) {
                    if (mStatusBar.isAlive()) {
                        return WindowManagerGlobal.ADD_MULTIPLE_SINGLETON;
                    }
                }
                mStatusBar = win;
                mStatusBarController.setWindow(win);
                break;
            case TYPE_NAVIGATION_BAR:
                mContext.enforceCallingOrSelfPermission(
                        android.Manifest.permission.STATUS_BAR_SERVICE,
                        "PhoneWindowManager");
                if (mNavigationBar != null) {
                    if (mNavigationBar.isAlive()) {
                        return WindowManagerGlobal.ADD_MULTIPLE_SINGLETON;
                    }
                }
                mNavigationBar = win;
                mNavigationBarController.setWindow(win);
                if (DEBUG_LAYOUT) Slog.i(TAG, "NAVIGATION BAR: " + mNavigationBar);
                break;
            case TYPE_NAVIGATION_BAR_PANEL:
            case TYPE_STATUS_BAR_PANEL:
            case TYPE_STATUS_BAR_SUB_PANEL:
            case TYPE_VOICE_INTERACTION_STARTING:
                mContext.enforceCallingOrSelfPermission(
                        android.Manifest.permission.STATUS_BAR_SERVICE,
                        "PhoneWindowManager");
                break;
            case TYPE_KEYGUARD_SCRIM:
                if (mKeyguardScrim != null) {
                    return WindowManagerGlobal.ADD_MULTIPLE_SINGLETON;
                }
                mKeyguardScrim = win;
                break;
        }
        return WindowManagerGlobal.ADD_OKAY;
    }

0x03. 分析

Dialog作为子窗口在显示的时候,父窗口已经不存在了,因此直接就抛出异常. 在代码实现中,如果要异步逻辑中要显示对话框,则必须要检测当前Activity是否存在.

浅析Android的窗口