Merge "Made creation of multiple stacks more intentional."

10 files changed, 148 insertions, 89 deletions

diff --git a/services/core/java/com/android/server/am/ActivityDisplay.java b/services/core/java/com/android/server/am/ActivityDisplay.java
index 6ed0555218af..089db871aa2f 100644
--- a/services/core/java/com/android/server/am/ActivityDisplay.java
+++ b/services/core/java/com/android/server/am/ActivityDisplay.java
@@ -20,6 +20,7 @@ import static android.app.WindowConfiguration.ACTIVITY_TYPE_HOME;
 import static android.app.WindowConfiguration.ACTIVITY_TYPE_RECENTS;
 import static android.app.WindowConfiguration.ACTIVITY_TYPE_STANDARD;
 import static android.app.WindowConfiguration.ACTIVITY_TYPE_UNDEFINED;
+import static android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM;
 import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
 import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN_OR_SPLIT_SCREEN_SECONDARY;
 import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;
@@ -168,9 +169,9 @@ class ActivityDisplay extends ConfigurationContainer<ActivityStack> {
         } else if (windowingMode == WINDOWING_MODE_SPLIT_SCREEN_PRIMARY) {
             return (T) mSplitScreenPrimaryStack;
         }
+
         for (int i = mStacks.size() - 1; i >= 0; --i) {
             final ActivityStack stack = mStacks.get(i);
-            // TODO: Should undefined windowing and activity type be compatible with standard type?
             if (stack.isCompatible(windowingMode, activityType)) {
                 return (T) stack;
             }
@@ -178,15 +179,28 @@ class ActivityDisplay extends ConfigurationContainer<ActivityStack> {
         return null;
     }
 
+    private boolean alwaysCreateStack(int windowingMode, int activityType) {
+        // Always create a stack for fullscreen, freeform, and split-screen-secondary windowing
+        // modes so that we can manage visual ordering and return types correctly.
+        return activityType == ACTIVITY_TYPE_STANDARD
+                && (windowingMode == WINDOWING_MODE_FULLSCREEN
+                || windowingMode == WINDOWING_MODE_FREEFORM
+                || windowingMode == WINDOWING_MODE_SPLIT_SCREEN_SECONDARY);
+    }
+
     /**
+     * Returns an existing stack compatible with the windowing mode and activity type or creates one
+     * if a compatible stack doesn't exist.
      * @see #getStack(int, int)
      * @see #createStack(int, int, boolean)
      */
     <T extends ActivityStack> T getOrCreateStack(int windowingMode, int activityType,
             boolean onTop) {
-        T stack = getStack(windowingMode, activityType);
-        if (stack != null) {
-            return stack;
+        if (!alwaysCreateStack(windowingMode, activityType)) {
+            T stack = getStack(windowingMode, activityType);
+            if (stack != null) {
+                return stack;
+            }
         }
         return createStack(windowingMode, activityType, onTop);
     }
@@ -238,17 +252,7 @@ class ActivityDisplay extends ConfigurationContainer<ActivityStack> {
             }
         }
 
-        final boolean inSplitScreenMode = hasSplitScreenPrimaryStack();
-        if (!inSplitScreenMode
-                && windowingMode == WINDOWING_MODE_FULLSCREEN_OR_SPLIT_SCREEN_SECONDARY) {
-            // Switch to fullscreen windowing mode if we are not in split-screen mode and we are
-            // trying to launch in split-screen secondary.
-            windowingMode = WINDOWING_MODE_FULLSCREEN;
-        } else if (inSplitScreenMode && windowingMode == WINDOWING_MODE_FULLSCREEN
-                && WindowConfiguration.supportSplitScreenWindowingMode(
-                        windowingMode, activityType)) {
-            windowingMode = WINDOWING_MODE_SPLIT_SCREEN_SECONDARY;
-        }
+        windowingMode = updateWindowingModeForSplitScreenIfNeeded(windowingMode, activityType);
 
         final int stackId = mSupervisor.getNextStackId();
 
@@ -420,6 +424,21 @@ class ActivityDisplay extends ConfigurationContainer<ActivityStack> {
         return mPinnedStack != null;
     }
 
+    int updateWindowingModeForSplitScreenIfNeeded(int windowingMode, int activityType) {
+        final boolean inSplitScreenMode = hasSplitScreenPrimaryStack();
+        if (!inSplitScreenMode
+                && windowingMode == WINDOWING_MODE_FULLSCREEN_OR_SPLIT_SCREEN_SECONDARY) {
+            // Switch to fullscreen windowing mode if we are not in split-screen mode and we are
+            // trying to launch in split-screen secondary.
+            return WINDOWING_MODE_FULLSCREEN;
+        } else if (inSplitScreenMode && windowingMode == WINDOWING_MODE_FULLSCREEN
+                && WindowConfiguration.supportSplitScreenWindowingMode(
+                windowingMode, activityType)) {
+            return WINDOWING_MODE_SPLIT_SCREEN_SECONDARY;
+        }
+        return windowingMode;
+    }
+
     @Override
     public String toString() {
         return "ActivityDisplay={" + mDisplayId + " numStacks=" + mStacks.size() + "}";
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index f17c9ac3ecf9..e1e53b3b0b31 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -4877,7 +4877,7 @@ public class ActivityManagerService extends IActivityManager.Stub
         final long origId = Binder.clearCallingIdentity();
         try {
             synchronized (this) {
-                return mStackSupervisor.startActivityFromRecentsInner(taskId, bOptions);
+                return mStackSupervisor.startActivityFromRecents(taskId, bOptions);
             }
         } finally {
             Binder.restoreCallingIdentity(origId);
@@ -14890,6 +14890,10 @@ public class ActivityManagerService extends IActivityManager.Stub
                 synchronized (this) {
                     dumpActivityStarterLocked(pw, dumpPackage);
                 }
+            } else if ("containers".equals(cmd)) {
+                synchronized (this) {
+                    dumpActivityContainersLocked(pw);
+                }
             } else if ("recents".equals(cmd) || "r".equals(cmd)) {
                 synchronized (this) {
                     if (mRecentTasks != null) {
@@ -15132,6 +15136,11 @@ public class ActivityManagerService extends IActivityManager.Stub
                 if (dumpAll) {
                     pw.println("-------------------------------------------------------------------------------");
                 }
+                dumpActivityContainersLocked(pw);
+                pw.println();
+                if (dumpAll) {
+                    pw.println("-------------------------------------------------------------------------------");
+                }
                 dumpActivitiesLocked(fd, pw, args, opti, dumpAll, dumpClient, dumpPackage);
                 if (mAssociations.size() > 0) {
                     pw.println();
@@ -15204,6 +15213,11 @@ public class ActivityManagerService extends IActivityManager.Stub
                 if (dumpAll) {
                     pw.println("-------------------------------------------------------------------------------");
                 }
+                dumpActivityContainersLocked(pw);
+                pw.println();
+                if (dumpAll) {
+                    pw.println("-------------------------------------------------------------------------------");
+                }
                 dumpActivitiesLocked(fd, pw, args, opti, dumpAll, dumpClient, dumpPackage);
                 if (mAssociations.size() > 0) {
                     pw.println();
@@ -15236,6 +15250,12 @@ public class ActivityManagerService extends IActivityManager.Stub
         }
     }
 
+    private void dumpActivityContainersLocked(PrintWriter pw) {
+        pw.println("ACTIVITY MANAGER STARTER (dumpsys activity containers)");
+        mStackSupervisor.dumpChildrenNames(pw, " ");
+        pw.println(" ");
+    }
+
     private void dumpActivityStarterLocked(PrintWriter pw, String dumpPackage) {
         pw.println("ACTIVITY MANAGER STARTER (dumpsys activity starter)");
         mActivityStarter.dump(pw, "", dumpPackage);
diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index f0811dda105e..941c371b717d 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -480,6 +480,29 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
         }
     }
 
+    @Override
+    public boolean isCompatible(int windowingMode, int activityType) {
+        // TODO: Should we just move this to ConfigurationContainer?
+        if (activityType == ACTIVITY_TYPE_UNDEFINED) {
+            // Undefined activity types end up in a standard stack once the stack is created on a
+            // display, so they should be considered compatible.
+            activityType = ACTIVITY_TYPE_STANDARD;
+        }
+        final ActivityDisplay display = getDisplay();
+        if (display != null) {
+            if (activityType == ACTIVITY_TYPE_STANDARD
+                    && windowingMode == WINDOWING_MODE_UNDEFINED) {
+                // Standard activity types will mostly take on the windowing mode of the display if
+                // one isn't specified, so look-up a compatible stack based on the display's
+                // windowing mode.
+                windowingMode = display.getWindowingMode();
+            }
+            windowingMode =
+                    display.updateWindowingModeForSplitScreenIfNeeded(windowingMode, activityType);
+        }
+        return super.isCompatible(windowingMode, activityType);
+    }
+
     /** Adds the stack to specified display and calls WindowManager to do the same. */
     void reparent(ActivityDisplay activityDisplay, boolean onTop) {
         removeFromDisplay();
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 5c91e3ccd050..736a766c7e2a 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -706,7 +706,7 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
     }
 
     TaskRecord anyTaskForIdLocked(int id, @AnyTaskForIdMatchTaskMode int matchMode) {
-        return anyTaskForIdLocked(id, matchMode, null);
+        return anyTaskForIdLocked(id, matchMode, null, !ON_TOP);
     }
 
     /**
@@ -714,11 +714,11 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
      * @param id Id of the task we would like returned.
      * @param matchMode The mode to match the given task id in.
      * @param aOptions The activity options to use for restoration. Can be null.
+     * @param onTop If the stack for the task should be the topmost on the display.
      */
     TaskRecord anyTaskForIdLocked(int id, @AnyTaskForIdMatchTaskMode int matchMode,
-            @Nullable ActivityOptions aOptions) {
-        // If there is a stack id set, ensure that we are attempting to actually restore a task
-        // TODO: Don't really know if this is needed...
+            @Nullable ActivityOptions aOptions, boolean onTop) {
+        // If options are set, ensure that we are attempting to actually restore a task
         if (matchMode != MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE && aOptions != null) {
             throw new IllegalArgumentException("Should not specify activity options for non-restore"
                     + " lookup");
@@ -730,9 +730,21 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             for (int stackNdx = display.getChildCount() - 1; stackNdx >= 0; --stackNdx) {
                 final ActivityStack stack = display.getChildAt(stackNdx);
                 final TaskRecord task = stack.taskForIdLocked(id);
-                if (task != null) {
-                    return task;
+                if (task == null) {
+                    continue;
                 }
+                if (aOptions != null) {
+                    // Resolve the stack the task should be placed in now based on options
+                    // and reparent if needed.
+                    final ActivityStack launchStack = getLaunchStack(null, aOptions, task, onTop);
+                    if (launchStack != null && stack != launchStack) {
+                        final int reparentMode = onTop
+                                ? REPARENT_MOVE_STACK_TO_FRONT : REPARENT_LEAVE_STACK_IN_PLACE;
+                        task.reparent(launchStack, onTop, reparentMode, ANIMATE, DEFER_RESUME,
+                                "anyTaskForIdLocked");
+                    }
+                }
+                return task;
             }
         }
 
@@ -759,7 +771,7 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
         }
 
         // Implicitly, this case is MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE
-        if (!restoreRecentTaskLocked(task, aOptions)) {
+        if (!restoreRecentTaskLocked(task, aOptions, onTop)) {
             if (DEBUG_RECENTS) Slog.w(TAG_RECENTS,
                     "Couldn't restore task id=" + id + " found in recents");
             return null;
@@ -2248,11 +2260,13 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             }
         }
 
-        if (isWindowingModeSupported(windowingMode, supportsMultiWindow, supportsSplitScreen,
+        if (windowingMode != WINDOWING_MODE_UNDEFINED
+                && isWindowingModeSupported(windowingMode, supportsMultiWindow, supportsSplitScreen,
                 supportsFreeform, supportsPip, activityType)) {
             return windowingMode;
         }
-        return WINDOWING_MODE_FULLSCREEN;
+        // Return root/systems windowing mode
+        return getWindowingMode();
     }
 
     int resolveActivityType(@Nullable ActivityRecord r, @Nullable ActivityOptions options,
@@ -2266,7 +2280,10 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
         if (activityType != ACTIVITY_TYPE_UNDEFINED) {
             return activityType;
         }
-        return options != null ? options.getLaunchActivityType() : ACTIVITY_TYPE_UNDEFINED;
+        if (options != null) {
+            activityType = options.getLaunchActivityType();
+        }
+        return activityType != ACTIVITY_TYPE_UNDEFINED ? activityType : ACTIVITY_TYPE_STANDARD;
     }
 
     <T extends ActivityStack> T getLaunchStack(@Nullable ActivityRecord r,
@@ -2304,7 +2321,7 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             // Temporarily set the task id to invalid in case in re-entry.
             options.setLaunchTaskId(INVALID_TASK_ID);
             final TaskRecord task = anyTaskForIdLocked(taskId,
-                    MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE, options);
+                    MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE, options, onTop);
             options.setLaunchTaskId(taskId);
             if (task != null) {
                 return task.getStack();
@@ -2330,13 +2347,10 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             }
             final ActivityDisplay display = getActivityDisplayOrCreateLocked(displayId);
             if (display != null) {
-                for (int i = display.getChildCount() - 1; i >= 0; --i) {
-                    stack = (T) display.getChildAt(i);
-                    if (stack.isCompatible(windowingMode, activityType)) {
-                        return stack;
-                    }
+                stack = display.getOrCreateStack(windowingMode, activityType, onTop);
+                if (stack != null) {
+                    return stack;
                 }
-                // TODO: We should create the stack we want on the display at this point.
             }
         }
 
@@ -2365,18 +2379,6 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             display = getDefaultDisplay();
         }
 
-        stack = display.getOrCreateStack(windowingMode, activityType, onTop);
-        if (stack != null) {
-            return stack;
-        }
-
-        // Whatever...return some default for now.
-        if (candidateTask != null && candidateTask.mBounds != null
-                && mService.mSupportsFreeformWindowManagement) {
-            windowingMode = WINDOWING_MODE_FREEFORM;
-        } else {
-            windowingMode = WINDOWING_MODE_FULLSCREEN;
-        }
         return display.getOrCreateStack(windowingMode, activityType, onTop);
     }
 
@@ -2967,10 +2969,11 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
      *
      * @param task The recent task to be restored.
      * @param aOptions The activity options to use for restoration.
+     * @param onTop If the stack for the task should be the topmost on the display.
      * @return true if the task has been restored successfully.
      */
-    boolean restoreRecentTaskLocked(TaskRecord task, ActivityOptions aOptions) {
-        final ActivityStack stack = getLaunchStack(null, aOptions, task, !ON_TOP);
+    boolean restoreRecentTaskLocked(TaskRecord task, ActivityOptions aOptions, boolean onTop) {
+        final ActivityStack stack = getLaunchStack(null, aOptions, task, onTop);
         final ActivityStack currentStack = task.getStack();
         if (currentStack != null) {
             // Task has already been restored once. See if we need to do anything more
@@ -2983,9 +2986,9 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             currentStack.removeTask(task, "restoreRecentTaskLocked", REMOVE_TASK_MODE_MOVING);
         }
 
-        stack.addTask(task, !ON_TOP, "restoreRecentTask");
+        stack.addTask(task, onTop, "restoreRecentTask");
         // TODO: move call for creation here and other place into Stack.addTask()
-        task.createWindowContainer(!ON_TOP, true /* showForAllUsers */);
+        task.createWindowContainer(onTop, true /* showForAllUsers */);
         if (DEBUG_RECENTS) Slog.v(TAG_RECENTS,
                 "Added restored task=" + task + " to stack=" + stack);
         final ArrayList<ActivityRecord> activities = task.mActivities;
@@ -4567,7 +4570,7 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
         task.setTaskDockedResizing(true);
     }
 
-    final int startActivityFromRecentsInner(int taskId, Bundle bOptions) {
+    int startActivityFromRecents(int taskId, Bundle bOptions) {
         final TaskRecord task;
         final int callingUid;
         final String callingPackage;
@@ -4582,7 +4585,7 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             windowingMode = activityOptions.getLaunchWindowingMode();
         }
         if (activityType == ACTIVITY_TYPE_HOME || activityType == ACTIVITY_TYPE_RECENTS) {
-            throw new IllegalArgumentException("startActivityFromRecentsInner: Task "
+            throw new IllegalArgumentException("startActivityFromRecents: Task "
                     + taskId + " can't be launch in the home/recents stack.");
         }
 
@@ -4600,21 +4603,12 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
             }
 
             task = anyTaskForIdLocked(taskId, MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE,
-                    activityOptions);
+                    activityOptions, ON_TOP);
             if (task == null) {
                 continueUpdateBounds(ACTIVITY_TYPE_RECENTS);
                 mWindowManager.executeAppTransition();
                 throw new IllegalArgumentException(
-                        "startActivityFromRecentsInner: Task " + taskId + " not found.");
-            }
-
-            // Since we don't have an actual source record here, we assume that the currently
-            // focused activity was the source.
-            final ActivityStack stack = getLaunchStack(null, activityOptions, task, ON_TOP);
-
-            if (stack != null && task.getStack() != stack) {
-                task.reparent(stack, ON_TOP, REPARENT_MOVE_STACK_TO_FRONT, ANIMATE, DEFER_RESUME,
-                        "startActivityFromRecents");
+                        "startActivityFromRecents: Task " + taskId + " not found.");
             }
 
             // If the user must confirm credentials (e.g. when first launching a work app and the
diff --git a/services/core/java/com/android/server/am/AppTaskImpl.java b/services/core/java/com/android/server/am/AppTaskImpl.java
index a4e2e70e0e60..d42a3b9bc1f0 100644
--- a/services/core/java/com/android/server/am/AppTaskImpl.java
+++ b/services/core/java/com/android/server/am/AppTaskImpl.java
@@ -94,7 +94,7 @@ class AppTaskImpl extends IAppTask.Stub {
         final long origId = Binder.clearCallingIdentity();
         try {
             synchronized (this) {
-                mService.mStackSupervisor.startActivityFromRecentsInner(mTaskId, null);
+                mService.mStackSupervisor.startActivityFromRecents(mTaskId, null);
             }
         } finally {
             Binder.restoreCallingIdentity(origId);
@@ -147,4 +147,4 @@ class AppTaskImpl extends IAppTask.Stub {
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index a1b45a1e1757..c4512353db94 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -60,6 +60,7 @@ import static com.android.server.am.ActivityManagerDebugConfig.TAG_WITH_CLASS_NA
 import static com.android.server.am.ActivityRecord.STARTING_WINDOW_SHOWN;
 import static com.android.server.am.ActivityStack.REMOVE_TASK_MODE_MOVING;
 import static com.android.server.am.ActivityStack.REMOVE_TASK_MODE_MOVING_TO_TOP;
+import static com.android.server.am.ActivityStackSupervisor.ON_TOP;
 import static com.android.server.am.ActivityStackSupervisor.PAUSE_IMMEDIATELY;
 import static com.android.server.am.ActivityStackSupervisor.PRESERVE_WINDOWS;
 import static com.android.server.am.proto.TaskRecordProto.ACTIVITIES;
@@ -512,7 +513,7 @@ class TaskRecord extends ConfigurationContainer implements TaskWindowContainerLi
             updateOverrideConfiguration(bounds);
             if (!inFreeformWindowingMode()) {
                 // re-restore the task so it can have the proper stack association.
-                mService.mStackSupervisor.restoreRecentTaskLocked(this, null);
+                mService.mStackSupervisor.restoreRecentTaskLocked(this, null, !ON_TOP);
             }
             return true;
         }
diff --git a/services/core/java/com/android/server/wm/ConfigurationContainer.java b/services/core/java/com/android/server/wm/ConfigurationContainer.java
index 5bfea98969bf..a4ab3ba33e18 100644
--- a/services/core/java/com/android/server/wm/ConfigurationContainer.java
+++ b/services/core/java/com/android/server/wm/ConfigurationContainer.java
@@ -28,6 +28,7 @@ import static android.app.WindowConfiguration.WINDOWING_MODE_SPLIT_SCREEN_PRIMAR
 import static android.app.WindowConfiguration.WINDOWING_MODE_SPLIT_SCREEN_SECONDARY;
 import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
 import static android.app.WindowConfiguration.activityTypeToString;
+import static android.app.WindowConfiguration.windowingModeToString;
 import static com.android.server.wm.proto.ConfigurationContainerProto.FULL_CONFIGURATION;
 import static com.android.server.wm.proto.ConfigurationContainerProto.MERGED_OVERRIDE_CONFIGURATION;
 import static com.android.server.wm.proto.ConfigurationContainerProto.OVERRIDE_CONFIGURATION;
@@ -37,6 +38,7 @@ import android.app.WindowConfiguration;
 import android.content.res.Configuration;
 import android.util.proto.ProtoOutputStream;
 
+import java.io.PrintWriter;
 import java.util.ArrayList;
 
 /**
@@ -342,6 +344,26 @@ public abstract class ConfigurationContainer<E extends ConfigurationContainer> {
         protoOutputStream.end(token);
     }
 
+    /**
+     * Dumps the names of this container children in the input print writer indenting each
+     * level with the input prefix.
+     */
+    public void dumpChildrenNames(PrintWriter pw, String prefix) {
+        final String childPrefix = prefix + " ";
+        pw.println(getName()
+                + " type=" + activityTypeToString(getActivityType())
+                + " mode=" + windowingModeToString(getWindowingMode()));
+        for (int i = getChildCount() - 1; i >= 0; --i) {
+            final E cc = getChildAt(i);
+            pw.print(childPrefix + "#" + i + " ");
+            cc.dumpChildrenNames(pw, childPrefix);
+        }
+    }
+
+    String getName() {
+        return toString();
+    }
+
     abstract protected int getChildCount();
 
     abstract protected E getChildAt(int index);
diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index 1b0825e5770a..563eb9cd1d88 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -674,20 +674,6 @@ a     * Returns whether this child is on top of the window hierarchy.
     }
 
     /**
-     * Dumps the names of this container children in the input print writer indenting each
-     * level with the input prefix.
-     */
-    void dumpChildrenNames(StringBuilder out, String prefix) {
-        final String childPrefix = prefix + " ";
-        out.append(getName() + "\n");
-        for (int i = mChildren.size() - 1; i >= 0; --i) {
-            final WindowContainer wc = mChildren.get(i);
-            out.append(childPrefix + "#" + i + " ");
-            wc.dumpChildrenNames(out, childPrefix);
-        }
-    }
-
-    /**
      * Write to a protocol buffer output stream. Protocol buffer message definition is at
      * {@link com.android.server.wm.proto.WindowContainerProto}.
      *
@@ -704,10 +690,6 @@ a     * Returns whether this child is on top of the window hierarchy.
         protoOutputStream.end(token);
     }
 
-    String getName() {
-        return toString();
-    }
-
     private ForAllWindowsConsumerWrapper obtainConsumerWrapper(Consumer<WindowState> consumer) {
         ForAllWindowsConsumerWrapper wrapper = mConsumerWrapperPool.acquire();
         if (wrapper == null) {
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index b133bd4502ef..f0da4742efa0 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -6921,9 +6921,7 @@ public class WindowManagerService extends IWindowManager.Stub
                 return;
             } else if ("containers".equals(cmd)) {
                 synchronized(mWindowMap) {
-                    StringBuilder output = new StringBuilder();
-                    mRoot.dumpChildrenNames(output, " ");
-                    pw.println(output.toString());
+                    mRoot.dumpChildrenNames(pw, " ");
                     pw.println(" ");
                     mRoot.forAllWindows(w -> {pw.println(w);}, true /* traverseTopToBottom */);
                 }
diff --git a/services/tests/servicestests/src/com/android/server/am/ActivityStackSupervisorTests.java b/services/tests/servicestests/src/com/android/server/am/ActivityStackSupervisorTests.java
index 6b93d0eaa71b..60a55fa941a7 100644
--- a/services/tests/servicestests/src/com/android/server/am/ActivityStackSupervisorTests.java
+++ b/services/tests/servicestests/src/com/android/server/am/ActivityStackSupervisorTests.java
@@ -77,7 +77,7 @@ public class ActivityStackSupervisorTests extends ActivityTestsBase {
     @Test
     public void testRestoringInvalidTask() throws Exception {
         TaskRecord task = mSupervisor.anyTaskForIdLocked(0 /*taskId*/,
-                MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE, null);
+                MATCH_TASK_IN_STACKS_OR_RECENT_TASKS_AND_RESTORE, null, false /* onTop */);
         assertNull(task);
     }
 
@@ -116,9 +116,9 @@ public class ActivityStackSupervisorTests extends ActivityTestsBase {
         mSupervisor.moveActivityToPinnedStackLocked(secondActivity, sourceBounds,
                 0f /*aspectRatio*/, false, "secondMove");
 
-        // Need to get pinned stack again as a new instance might have been created.
+        // Need to get stacks again as a new instance might have been created.
         pinnedStack = display.getPinnedStack();
-
+        mFullscreenStack = display.getStack(WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD);
         // Ensure stacks have swapped tasks.
         ensureStackPlacement(pinnedStack, secondTask);
         ensureStackPlacement(mFullscreenStack, firstTask);