[wm]: Changed an order to set a target window in TaskPositioner.

The system crash happens in TaskPositioner.unregister()
with the line mClientCallback.unlinkToDeath(this, 0 /* flags */).
Because mClientCallback has not been initialized before starting window drag.

Send the target window at the register function not at the start function.

Test: manual - Drag freefrom windowing task repeatedly
Test: atest WmTests:TaskPositionerTests
Bug: 142746031
Change-Id: Ied605f35d8b50540ad01056fa87bb2637135f1ab
(cherry picked from commit ac5ad99b44ea26aae1571de36c039eed81e886cf)

3 files changed, 60 insertions, 55 deletions

diff --git a/services/core/java/com/android/server/wm/TaskPositioner.java b/services/core/java/com/android/server/wm/TaskPositioner.java
index 478b1b533f4c..961f9737bcea 100644
--- a/services/core/java/com/android/server/wm/TaskPositioner.java
+++ b/services/core/java/com/android/server/wm/TaskPositioner.java
@@ -30,6 +30,7 @@ import static com.android.server.wm.WindowState.MINIMUM_VISIBLE_HEIGHT_IN_DP;
 import static com.android.server.wm.WindowState.MINIMUM_VISIBLE_WIDTH_IN_DP;
 
 import android.annotation.IntDef;
+import android.annotation.NonNull;
 import android.app.IActivityTaskManager;
 import android.graphics.Point;
 import android.graphics.Rect;
@@ -104,6 +105,7 @@ class TaskPositioner implements IBinder.DeathRecipient {
 
     @VisibleForTesting
     Task mTask;
+    WindowState mWindow;
     private boolean mResizing;
     private boolean mPreserveOrientation;
     private boolean mStartOrientationWasLandscape;
@@ -238,8 +240,9 @@ class TaskPositioner implements IBinder.DeathRecipient {
 
     /**
      * @param displayContent The Display that the window being dragged is on.
+     * @param win The window which will be dragged.
      */
-    void register(DisplayContent displayContent) {
+    void register(DisplayContent displayContent, @NonNull WindowState win) {
         final Display display = displayContent.getDisplay();
 
         if (DEBUG_TASK_POSITIONING) {
@@ -309,6 +312,17 @@ class TaskPositioner implements IBinder.DeathRecipient {
         display.getRealSize(mMaxVisibleSize);
 
         mDragEnded = false;
+
+        try {
+            mClientCallback = win.mClient.asBinder();
+            mClientCallback.linkToDeath(this, 0 /* flags */);
+        } catch (RemoteException e) {
+            // The caller has died, so clean up TaskPositioningController.
+            mService.mTaskPositioningController.finishTaskPositioning();
+            return;
+        }
+        mWindow = win;
+        mTask = win.getTask();
     }
 
     void unregister() {
@@ -341,25 +355,19 @@ class TaskPositioner implements IBinder.DeathRecipient {
         ProtoLog.d(WM_DEBUG_ORIENTATION, "Resuming rotation after re-position");
         mDisplayContent.getDisplayRotation().resume();
         mDisplayContent = null;
-        mClientCallback.unlinkToDeath(this, 0 /* flags */);
+        if (mClientCallback != null) {
+            mClientCallback.unlinkToDeath(this, 0 /* flags */);
+        }
+        mWindow = null;
     }
 
-    void startDrag(WindowState win, boolean resize, boolean preserveOrientation, float startX,
-                   float startY) {
+    void startDrag(boolean resize, boolean preserveOrientation, float startX,
+            float startY) {
         if (DEBUG_TASK_POSITIONING) {
-            Slog.d(TAG, "startDrag: win=" + win + ", resize=" + resize
+            Slog.d(TAG, "startDrag: win=" + mWindow + ", resize=" + resize
                     + ", preserveOrientation=" + preserveOrientation + ", {" + startX + ", "
                     + startY + "}");
         }
-        try {
-            mClientCallback = win.mClient.asBinder();
-            mClientCallback.linkToDeath(this, 0 /* flags */);
-        } catch (RemoteException e) {
-            // The caller has died, so clean up TaskPositioningController.
-            mService.mTaskPositioningController.finishTaskPositioning();
-            return;
-        }
-        mTask = win.getTask();
         // Use the bounds of the task which accounts for
         // multiple app windows. Don't use any bounds from win itself as it
         // may not be the same size as the task.
diff --git a/services/core/java/com/android/server/wm/TaskPositioningController.java b/services/core/java/com/android/server/wm/TaskPositioningController.java
index e1123fa05b7d..c38e63e54239 100644
--- a/services/core/java/com/android/server/wm/TaskPositioningController.java
+++ b/services/core/java/com/android/server/wm/TaskPositioningController.java
@@ -169,7 +169,7 @@ class TaskPositioningController {
         mPositioningDisplay = displayContent;
 
         mTaskPositioner = TaskPositioner.create(mService);
-        mTaskPositioner.register(displayContent);
+        mTaskPositioner.register(displayContent, win);
 
         // We need to grab the touch focus so that the touch events during the
         // resizing/scrolling are not sent to the app. 'win' is the main window
@@ -187,7 +187,7 @@ class TaskPositioningController {
             return false;
         }
 
-        mTaskPositioner.startDrag(win, resize, preserveOrientation, startX, startY);
+        mTaskPositioner.startDrag(resize, preserveOrientation, startX, startY);
         return true;
     }
 
diff --git a/services/tests/wmtests/src/com/android/server/wm/TaskPositionerTests.java b/services/tests/wmtests/src/com/android/server/wm/TaskPositionerTests.java
index 012eb5252c50..9275512bc719 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TaskPositionerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TaskPositionerTests.java
@@ -66,7 +66,6 @@ public class TaskPositionerTests extends WindowTestsBase {
     private int mMinVisibleWidth;
     private int mMinVisibleHeight;
     private TaskPositioner mPositioner;
-    private WindowState mWindow;
 
     @Before
     public void setUp() {
@@ -81,17 +80,16 @@ public class TaskPositionerTests extends WindowTestsBase {
         mMinVisibleHeight = dipToPixel(MINIMUM_VISIBLE_HEIGHT_IN_DP, dm);
         removeGlobalMinSizeRestriction();
 
+        WindowState win = createWindow(null, TYPE_BASE_APPLICATION, "window");
         mPositioner = new TaskPositioner(mWm, mWm.mAtmService);
-        mPositioner.register(mDisplayContent);
 
-        mWindow = createWindow(null, TYPE_BASE_APPLICATION, "window");
-        mPositioner.mTask = mWindow.getTask();
-        mWindow.getStack().setWindowingMode(WINDOWING_MODE_FREEFORM);
+        mPositioner.register(mDisplayContent, win);
+
+        win.getStack().setWindowingMode(WINDOWING_MODE_FREEFORM);
     }
 
     @After
     public void tearDown() {
-        mWindow = null;
         mPositioner = null;
     }
 
@@ -122,8 +120,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         mPositioner.mTask.setBounds(r, true);
 
         // Start a drag resize starting upper left.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
         assertBoundsEquals(r, mPositioner.getWindowDragBounds());
 
         // Drag to a good landscape size.
@@ -149,8 +147,8 @@ public class TaskPositionerTests extends WindowTestsBase {
                 mPositioner.getWindowDragBounds());
 
         // Start a drag resize left and see that only the left coord changes..
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.left - MOUSE_DELTA_X, midY);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, midY);
 
         // Drag to the left.
         mPositioner.resizeDrag(0.0f, midY);
@@ -184,8 +182,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         mPositioner.mTask.setBounds(r, true);
 
         // Drag upper left.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
         mPositioner.resizeDrag(0.0f, 0.0f);
         assertNotEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -193,8 +191,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag upper.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, midX, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */, midX,
+                r.top - MOUSE_DELTA_Y);
         mPositioner.resizeDrag(0.0f, 0.0f);
         assertEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -202,8 +200,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag upper right.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.right + MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.right + MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
         mPositioner.resizeDrag(r.right + 100, 0.0f);
         assertEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertNotEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -211,8 +209,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag right.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.right + MOUSE_DELTA_X, midY);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.right + MOUSE_DELTA_X, midY);
         mPositioner.resizeDrag(r.right + 100, 0.0f);
         assertEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertNotEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -220,8 +218,7 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag bottom right.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */,
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
                 r.right + MOUSE_DELTA_X, r.bottom + MOUSE_DELTA_Y);
         mPositioner.resizeDrag(r.right + 100, r.bottom + 100);
         assertEquals(r.left, mPositioner.getWindowDragBounds().left);
@@ -230,8 +227,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertNotEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag bottom.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, midX, r.bottom + MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */, midX,
+                r.bottom + MOUSE_DELTA_Y);
         mPositioner.resizeDrag(r.right + 100, r.bottom + 100);
         assertEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -239,8 +236,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertNotEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag bottom left.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.left - MOUSE_DELTA_X, r.bottom + MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, r.bottom + MOUSE_DELTA_Y);
         mPositioner.resizeDrag(0.0f, r.bottom + 100);
         assertNotEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -248,8 +245,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         assertNotEquals(r.bottom, mPositioner.getWindowDragBounds().bottom);
 
         // Drag left.
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                false /* preserveOrientation */, r.left - MOUSE_DELTA_X, midY);
+        mPositioner.startDrag(true /* resizing */, false /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, midY);
         mPositioner.resizeDrag(0.0f, r.bottom + 100);
         assertNotEquals(r.left, mPositioner.getWindowDragBounds().left);
         assertEquals(r.right, mPositioner.getWindowDragBounds().right);
@@ -266,8 +263,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         final Rect r = new Rect(100, 220, 700, 520);
         mPositioner.mTask.setBounds(r, true);
 
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                true /* preserveOrientation */, r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, true /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
         assertBoundsEquals(r, mPositioner.getWindowDragBounds());
 
         // Drag to a good landscape size.
@@ -305,8 +302,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         final int midY = (r.top + r.bottom) / 2;
         mPositioner.mTask.setBounds(r, true);
 
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                true /* preserveOrientation */, r.left - MOUSE_DELTA_X, midY);
+        mPositioner.startDrag(true /* resizing */, true /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, midY);
 
         // Drag to the left.
         mPositioner.resizeDrag(0.0f, midY);
@@ -346,8 +343,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         final int midX = (r.left + r.right) / 2;
         mPositioner.mTask.setBounds(r, true);
 
-        mPositioner.startDrag(mWindow, true /*resizing*/,
-                true /*preserveOrientation*/, midX, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /*resizing*/, true /*preserveOrientation*/, midX,
+                r.top - MOUSE_DELTA_Y);
 
         // Drag to the left (no change).
         mPositioner.resizeDrag(0.0f, r.top);
@@ -382,8 +379,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         final Rect r = new Rect(330, 100, 630, 600);
         mPositioner.mTask.setBounds(r, true);
 
-        mPositioner.startDrag(mWindow, true /*resizing*/,
-                true /*preserveOrientation*/, r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /*resizing*/, true /*preserveOrientation*/,
+                r.left - MOUSE_DELTA_X, r.top - MOUSE_DELTA_Y);
         assertBoundsEquals(r, mPositioner.getWindowDragBounds());
 
         // Drag to a good landscape size.
@@ -416,8 +413,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         final int midY = (r.top + r.bottom) / 2;
         mPositioner.mTask.setBounds(r, true);
 
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                true /* preserveOrientation */, r.left - MOUSE_DELTA_X, midY);
+        mPositioner.startDrag(true /* resizing */, true /* preserveOrientation */,
+                r.left - MOUSE_DELTA_X, midY);
 
         // Drag to the left.
         mPositioner.resizeDrag(0.0f, midY);
@@ -459,8 +456,8 @@ public class TaskPositionerTests extends WindowTestsBase {
         final int midX = (r.left + r.right) / 2;
         mPositioner.mTask.setBounds(r, true);
 
-        mPositioner.startDrag(mWindow, true /* resizing */,
-                true /* preserveOrientation */, midX, r.top - MOUSE_DELTA_Y);
+        mPositioner.startDrag(true /* resizing */, true /* preserveOrientation */, midX,
+                r.top - MOUSE_DELTA_Y);
 
         // Drag to the left (no change).
         mPositioner.resizeDrag(0.0f, r.top);
@@ -502,7 +499,7 @@ public class TaskPositionerTests extends WindowTestsBase {
     public void testFinishingMovingWhenBinderDied() {
         spyOn(mWm.mTaskPositioningController);
 
-        mPositioner.startDrag(mWindow, false, false, 0 /* startX */, 0 /* startY */);
+        mPositioner.startDrag(false, false, 0 /* startX */, 0 /* startY */);
         verify(mWm.mTaskPositioningController, never()).finishTaskPositioning();
         mPositioner.binderDied();
         verify(mWm.mTaskPositioningController).finishTaskPositioning();