commit cb4dbb8b80a52997e179e6f26943aecdd971b3ed
author Catherine Shi <li.shi@gm.com> Mon Jun 22 12:12:03 2020 -0700
committer Agatha Man <agathaman@google.com> Tue Aug 18 16:57:31 2020 +0000
tree adc495aead65e9ae1ff8da1c05871c0f90cb784a
parent 3743d5526ac7a43d486a109b521dafa7a8a87874

system server watchdog caused by deadlock

There is deadlock among ActivityManagerService, ActivityTaskManagerService
and ConnectionServiceWrapper. Move stopLockTaskModeInternal out of mGlobalLock scope.
This will remove the deadlock

Bug: 159213837
Bug: 162950591
Test: presubmit
Change-Id: I6aee6f9837bac22e480f42124bfcdba991e0fa1a
(cherry picked from commit 3a17ba2f2560405ee8415d2d652eb3dd3c7449fc)

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

diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 5992ff7..52d4b6f 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -2997,13 +2997,7 @@
 
     @Override
     public void stopLockTaskModeByToken(IBinder token) {
-        synchronized (mGlobalLock) {
-            final ActivityRecord r = ActivityRecord.forTokenLocked(token);
-            if (r == null) {
-                return;
-            }
-            stopLockTaskModeInternal(r.getTask(), false /* isSystemCaller */);
-        }
+        stopLockTaskModeInternal(token, false /* isSystemCaller */);
     }
 
     /**
@@ -3045,11 +3039,19 @@
         }
     }
 
-    private void stopLockTaskModeInternal(@Nullable Task task, boolean isSystemCaller) {
+    private void stopLockTaskModeInternal(@Nullable IBinder token, boolean isSystemCaller) {
         final int callingUid = Binder.getCallingUid();
         long ident = Binder.clearCallingIdentity();
         try {
             synchronized (mGlobalLock) {
+                Task task = null;
+                if (token != null) {
+                    final ActivityRecord r = ActivityRecord.forTokenLocked(token);
+                    if (r == null) {
+                        return;
+                    }
+                    task = r.getTask();
+                }
                 getLockTaskController().stopLockTaskMode(task, isSystemCaller, callingUid);
             }
             // Launch in-call UI if a call is ongoing. This is necessary to allow stopping the lock