Merge "Don't call into AM finish-recents-animation while holding onto the WM lock" into pi-dev

services/core/java/com/android/server/am/ActivityManagerService.java

@@ -5306,7 +5306,8 @@ public class ActivityManagerService extends IActivityManager.Stub
         final long origId = Binder.clearCallingIdentity();
         try {
             synchronized (this) {
-                mWindowManager.cancelRecentsAnimation(restoreHomeStackPosition
+                // Cancel the recents animation synchronously (do not hold the WM lock)
+                mWindowManager.cancelRecentsAnimationSynchronously(restoreHomeStackPosition
                         ? REORDER_MOVE_TO_ORIGINAL_POSITION
                         : REORDER_KEEP_IN_PLACE, "cancelRecentsAnimation");
             }

services/core/java/com/android/server/am/RecentsAnimation.java

@@ -179,8 +179,9 @@ class RecentsAnimation implements RecentsAnimationCallbacks {
             targetActivity.mLaunchTaskBehind = true;
 
             // Fetch all the surface controls and pass them to the client to get the animation
-            // started
-            mWindowManager.cancelRecentsAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION,
+            // started. Cancel any existing recents animation running synchronously (do not hold the
+            // WM lock)
+            mWindowManager.cancelRecentsAnimationSynchronously(REORDER_MOVE_TO_ORIGINAL_POSITION,
                     "startRecentsActivity");
             mWindowManager.initializeRecentsAnimation(mTargetActivityType, recentsAnimationRunner,
                     this, display.mDisplayId, mStackSupervisor.mRecentTasks.getRecentTaskIds());
@@ -200,12 +201,11 @@ class RecentsAnimation implements RecentsAnimationCallbacks {
         }
     }
 
-    @Override
-    public void onAnimationFinished(@RecentsAnimationController.ReorderMode int reorderMode) {
+    private void finishAnimation(@RecentsAnimationController.ReorderMode int reorderMode) {
         synchronized (mService) {
             if (DEBUG) Slog.d(TAG, "onAnimationFinished(): controller="
-                        + mWindowManager.getRecentsAnimationController()
-                        + " reorderMode=" + reorderMode);
+                    + mWindowManager.getRecentsAnimationController()
+                    + " reorderMode=" + reorderMode);
 
             // Cancel the associated assistant data request
             if (mAssistDataRequester != null) {
@@ -298,6 +298,16 @@ class RecentsAnimation implements RecentsAnimationCallbacks {
         }
     }
 
+    @Override
+    public void onAnimationFinished(@RecentsAnimationController.ReorderMode int reorderMode,
+            boolean runSychronously) {
+        if (runSychronously) {
+            finishAnimation(reorderMode);
+        } else {
+            mService.mHandler.post(() -> finishAnimation(reorderMode));
+        }
+    }
+
     /**
      * Called only when the animation should be canceled prior to starting.
      */

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

@@ -83,9 +83,8 @@ public class RecentsAnimationController implements DeathRecipient {
     private final RecentsAnimationCallbacks mCallbacks;
     private final ArrayList<TaskAnimationAdapter> mPendingAnimations = new ArrayList<>();
     private final int mDisplayId;
-    private final Runnable mFailsafeRunnable = () -> {
-        cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "failSafeRunnable");
-    };
+    private final Runnable mFailsafeRunnable = () ->
+            cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "failSafeRunnable");
 
     // The recents component app token that is shown behind the visibile tasks
     private AppWindowToken mTargetAppToken;
@@ -112,7 +111,7 @@ public class RecentsAnimationController implements DeathRecipient {
     private boolean mLinkedToDeathOfRunner;
 
     public interface RecentsAnimationCallbacks {
-        void onAnimationFinished(@ReorderMode int reorderMode);
+        void onAnimationFinished(@ReorderMode int reorderMode, boolean runSychronously);
     }
 
     private final IRecentsAnimationController mController =
@@ -164,7 +163,8 @@ public class RecentsAnimationController implements DeathRecipient {
                 // prior to calling the callback
                 mCallbacks.onAnimationFinished(moveHomeToTop
                         ? REORDER_MOVE_TO_TOP
-                        : REORDER_MOVE_TO_ORIGINAL_POSITION);
+                        : REORDER_MOVE_TO_ORIGINAL_POSITION,
+                        true /* runSynchronously */);
             } finally {
                 Binder.restoreCallingIdentity(token);
             }
@@ -385,7 +385,17 @@ public class RecentsAnimationController implements DeathRecipient {
     }
 
     void cancelAnimation(@ReorderMode int reorderMode, String reason) {
-        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "cancelAnimation(): reason=" + reason);
+        cancelAnimation(reorderMode, false /* runSynchronously */, reason);
+    }
+
+    void cancelAnimationSynchronously(@ReorderMode int reorderMode, String reason) {
+        cancelAnimation(reorderMode, true /* runSynchronously */, reason);
+    }
+
+    private void cancelAnimation(@ReorderMode int reorderMode, boolean runSynchronously,
+            String reason) {
+        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "cancelAnimation(): reason=" + reason
+                + " runSynchronously=" + runSynchronously);
         synchronized (mService.getWindowManagerLock()) {
             if (mCanceled) {
                 // We've already canceled the animation
@@ -401,8 +411,7 @@ public class RecentsAnimationController implements DeathRecipient {
         }
 
         // Clean up and return to the previous app
-        // Don't hold the WM lock here as it calls back to AM/RecentsAnimation
-        mCallbacks.onAnimationFinished(reorderMode);
+        mCallbacks.onAnimationFinished(reorderMode, runSynchronously);
     }
 
     void cleanupAnimation(@ReorderMode int reorderMode) {

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

@@ -2732,17 +2732,15 @@ public class WindowManagerService extends IWindowManager.Stub
 
     /**
      * Cancels any running recents animation. The caller should NOT hold the WM lock while calling
-     * this method, as it can call back into AM, and locking will be done in the animation
-     * controller itself.
+     * this method, as it will call back into AM and may cause a deadlock. Any locking will be done
+     * in the animation controller itself.
      */
-    public void cancelRecentsAnimation(@RecentsAnimationController.ReorderMode int reorderMode,
-            String reason) {
-        // Note: Do not hold the WM lock, this will lock appropriately in the call which also
-        // calls through to AM/RecentsAnimation.onAnimationFinished()
+    public void cancelRecentsAnimationSynchronously(
+            @RecentsAnimationController.ReorderMode int reorderMode, String reason) {
         if (mRecentsAnimationController != null) {
             // This call will call through to cleanupAnimation() below after the animation is
             // canceled
-            mRecentsAnimationController.cancelAnimation(reorderMode, reason);
+            mRecentsAnimationController.cancelAnimationSynchronously(reorderMode, reason);
         }
     }