Merge "Call InputEventReceiver.dispose from the right thread"

core/java/android/view/InputEventReceiver.java

@@ -25,6 +25,7 @@ import android.util.SparseIntArray;
 
 import dalvik.system.CloseGuard;
 
+import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 
 /**
@@ -86,6 +87,7 @@ public abstract class InputEventReceiver {
 
     /**
      * Disposes the receiver.
+     * Must be called on the same Looper thread to which the receiver is attached.
      */
     public void dispose() {
         dispose(false);
@@ -109,6 +111,7 @@ public abstract class InputEventReceiver {
             mInputChannel = null;
         }
         mMessageQueue = null;
+        Reference.reachabilityFence(this);
     }
 
     /**

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

@@ -198,7 +198,9 @@ class TaskPositioningController {
     }
 
     void finishTaskPositioning() {
-        mHandler.post(() -> {
+        // TaskPositioner attaches the InputEventReceiver to the animation thread. We need to
+        // dispose the receiver on the same thread to avoid race conditions.
+        mService.mAnimationHandler.post(() -> {
             if (DEBUG_TASK_POSITIONING) Slog.d(TAG_WM, "finishPositioning");
 
             synchronized (mService.mGlobalLock) {