From 249a06ba04b7bdf1a7bc0d1bc5658a7787d19ff4 Mon Sep 17 00:00:00 2001
From: Evan Rosky <erosky@google.com>
Date: Fri, 18 Jun 2021 21:00:15 -0700
Subject: [PATCH] Register binder-depth per remote animation

Was just clearing all registered remotes. However, not all
remotes are from the same process, so things can get messed-up
(since we aren't relaunching the non-crashed binders, they won't
re-register). This is useful both for robustness as well as
making that failing tests don't break all subsequent tests.

This makes a death recipient for each remote.

Bug: 183993924
Test: crash launcher, make sure remote keyguard transition still
      works.
Change-Id: Idbec7ff72afd9bac974e7dbb1a067ad237606bd7
---
 .../transition/RemoteTransitionHandler.java   | 37 ++++++++++++++-----
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/RemoteTransitionHandler.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/RemoteTransitionHandler.java
index e67186fcf6408..f432049f44f63 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/RemoteTransitionHandler.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/RemoteTransitionHandler.java
@@ -56,14 +56,7 @@ public class RemoteTransitionHandler implements Transitions.TransitionHandler {
     private final ArrayList<Pair<TransitionFilter, IRemoteTransition>> mFilters =
             new ArrayList<>();
 
-    private final IBinder.DeathRecipient mTransitionDeathRecipient =
-            new IBinder.DeathRecipient() {
-                @Override
-                @BinderThread
-                public void binderDied() {
-                    mMainExecutor.execute(() -> mFilters.clear());
-                }
-            };
+    private final ArrayMap<IBinder, RemoteDeathHandler> mDeathHandlers = new ArrayMap<>();
 
     RemoteTransitionHandler(@NonNull ShellExecutor mainExecutor) {
         mMainExecutor = mainExecutor;
@@ -71,7 +64,9 @@ public class RemoteTransitionHandler implements Transitions.TransitionHandler {
 
     void addFiltered(TransitionFilter filter, IRemoteTransition remote) {
         try {
-            remote.asBinder().linkToDeath(mTransitionDeathRecipient, 0 /* flags */);
+            RemoteDeathHandler handler = new RemoteDeathHandler(remote.asBinder());
+            remote.asBinder().linkToDeath(handler, 0 /* flags */);
+            mDeathHandlers.put(remote.asBinder(), handler);
         } catch (RemoteException e) {
             Slog.e(TAG, "Failed to link to death");
             return;
@@ -88,7 +83,8 @@ public class RemoteTransitionHandler implements Transitions.TransitionHandler {
             }
         }
         if (removed) {
-            remote.asBinder().unlinkToDeath(mTransitionDeathRecipient, 0 /* flags */);
+            RemoteDeathHandler handler = mDeathHandlers.remove(remote.asBinder());
+            remote.asBinder().unlinkToDeath(handler, 0 /* flags */);
         }
     }
 
@@ -206,4 +202,25 @@ public class RemoteTransitionHandler implements Transitions.TransitionHandler {
                 + " for %s: %s", transition, remote);
         return new WindowContainerTransaction();
     }
+
+    /** NOTE: binder deaths can alter the filter order */
+    private class RemoteDeathHandler implements IBinder.DeathRecipient {
+        private final IBinder mRemote;
+
+        RemoteDeathHandler(IBinder remote) {
+            mRemote = remote;
+        }
+
+        @Override
+        @BinderThread
+        public void binderDied() {
+            mMainExecutor.execute(() -> {
+                for (int i = mFilters.size() - 1; i >= 0; --i) {
+                    if (mRemote.equals(mFilters.get(i).second.asBinder())) {
+                        mFilters.remove(i);
+                    }
+                }
+            });
+        }
+    }
 }