LocationManagerService: Fix race when removing LocationListener

In LocationManagerService if a LocationListener is removed while it has
a pending broadcast the wake lock held while pending broadcasts are
outstanding do not get cleared properly.

There are 2 cases of this race that are fixed:

1. locationCallbackFinished was changed to check the mReceivers HashMap
directly instead of calling getReceiver.  getReceiver would add the
ILocationListener as a new Receiver if it did not exist which caused
a receiver that was removed when it still had a broadcast pending to
be added back in a bad state when the pending broadcast completed.

2. removeUpdatesLocked was changed to decrement the pending broadcasts
when a Receiver is removed that has pending broadcasts.

Fixes bug b/2163871

Change-Id: I50a321c9b3359bf69845236dc4a4b9e38e847335
Signed-off-by: Mike Lockwood <lockwood@android.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index f6a1be73328f..c8fa4c39ad03 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -382,7 +382,12 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
     }
 
     public void locationCallbackFinished(ILocationListener listener) {
-        Receiver receiver = getReceiver(listener);
+        //Do not use getReceiver here as that will add the ILocationListener to
+        //the receiver list if it is not found.  If it is not found then the
+        //LocationListener was removed when it had a pending broadcast and should
+        //not be added back.
+        IBinder binder = listener.asBinder();
+        Receiver receiver = mReceivers.get(binder);
         if (receiver != null) {
             synchronized (receiver) {
                 // so wakelock calls will succeed
@@ -921,6 +926,12 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
         try {
             if (mReceivers.remove(receiver.mKey) != null && receiver.isListener()) {
                 receiver.getListener().asBinder().unlinkToDeath(receiver, 0);
+                synchronized(receiver) {
+                    if(receiver.mPendingBroadcasts > 0) {
+                        decrementPendingBroadcasts();
+                        receiver.mPendingBroadcasts = 0;
+                    }
+                }
             }
 
             // Record which providers were associated with this listener