Merge "Quick fix for possible deadlock in LMS" into rvc-dev am: 45b8146ae8 am: 98c1646443 am: 4ec5b2f0ff am: 5d2e7f95e9

Change-Id: I418c5c6b5321913989f090afb03be541c73324a4

1 files changed, 15 insertions, 9 deletions

diff --git a/location/java/android/location/LocationManager.java b/location/java/android/location/LocationManager.java
index d275337e8ee2..7523f07674ea 100644
--- a/location/java/android/location/LocationManager.java
+++ b/location/java/android/location/LocationManager.java
@@ -2496,22 +2496,28 @@ public class LocationManager {
             mRemoteCancellationSignal = remoteCancellationSignal;
         }
 
-        public synchronized void cancel() {
-            mExecutor = null;
-            mConsumer = null;
+        public void cancel() {
+            ICancellationSignal cancellationSignal;
+            synchronized (this) {
+                mExecutor = null;
+                mConsumer = null;
 
-            if (mAlarmManager != null) {
-                mAlarmManager.cancel(this);
-                mAlarmManager = null;
+                if (mAlarmManager != null) {
+                    mAlarmManager.cancel(this);
+                    mAlarmManager = null;
+                }
+
+                // ensure only one cancel event will go through
+                cancellationSignal = mRemoteCancellationSignal;
+                mRemoteCancellationSignal = null;
             }
 
-            if (mRemoteCancellationSignal != null) {
+            if (cancellationSignal != null) {
                 try {
-                    mRemoteCancellationSignal.cancel();
+                    cancellationSignal.cancel();
                 } catch (RemoteException e) {
                     // ignore
                 }
-                mRemoteCancellationSignal = null;
             }
         }