From 7ceb724d0f792897e66fca8566fcabca969c5b57 Mon Sep 17 00:00:00 2001
From: Yifan Hong <elsk@google.com>
Date: Fri, 16 Aug 2019 13:20:57 -0700
Subject: [PATCH] BatteryService: scheduleUpdate asynchronously

IBatteryPropertiesRegistrar.scheduleUpdate calls IHealth.update()
asynchronously.

BatteryStatsImpl calls scheduleUpdate while holding a lock, which
may lead to deadlocks if the remote process calls back to the
framework.

Fixes: 139503418
Test: monitor HealthScheduleUpdate trace points
Change-Id: I8168d7c4e4a0b1d31343360d2c7f6d36c7aa692a
---
 .../java/com/android/server/BatteryService.java    | 25 ++++++++++++++--------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/services/core/java/com/android/server/BatteryService.java b/services/core/java/com/android/server/BatteryService.java
index 3b78fdafbd94..946561788d80 100644
--- a/services/core/java/com/android/server/BatteryService.java
+++ b/services/core/java/com/android/server/BatteryService.java
@@ -1227,14 +1227,21 @@ public final class BatteryService extends SystemService {
         }
         @Override
         public void scheduleUpdate() throws RemoteException {
-            traceBegin("HealthScheduleUpdate");
-            try {
-                IHealth service = mHealthServiceWrapper.getLastService();
-                if (service == null) throw new RemoteException("no health service");
-                service.update();
-            } finally {
-                traceEnd();
-            }
+            mHealthServiceWrapper.getHandlerThread().getThreadHandler().post(() -> {
+                traceBegin("HealthScheduleUpdate");
+                try {
+                    IHealth service = mHealthServiceWrapper.getLastService();
+                    if (service == null) {
+                        Slog.e(TAG, "no health service");
+                        return;
+                    }
+                    service.update();
+                } catch (RemoteException ex) {
+                    Slog.e(TAG, "Cannot call update on health HAL", ex);
+                } finally {
+                    traceEnd();
+                }
+            });
         }
     }
 
@@ -1311,7 +1318,7 @@ public final class BatteryService extends SystemService {
                 Arrays.asList(INSTANCE_VENDOR, INSTANCE_HEALTHD);
 
         private final IServiceNotification mNotification = new Notification();
-        private final HandlerThread mHandlerThread = new HandlerThread("HealthServiceRefresh");
+        private final HandlerThread mHandlerThread = new HandlerThread("HealthServiceHwbinder");
         // These variables are fixed after init.
         private Callback mCallback;
         private IHealthSupplier mHealthSupplier;
-- 
2.11.0