Support multiple caches in NetworkScoreService.

- Use RemoteCallbackList for managing multiple callbacks
- Add unregisterNetworkScoreCache to the service interface
- Added NetworkScoreServiceTest

Test: runtest frameworks-services

Bug: 32913019
Change-Id: I16ca1682acca9cbe403812e520394688a026414b

2 files changed, 29 insertions, 2 deletions

diff --git a/core/java/android/net/INetworkScoreService.aidl b/core/java/android/net/INetworkScoreService.aidl
index 59cbf6e93894..542a0a7d4040 100644
--- a/core/java/android/net/INetworkScoreService.aidl
+++ b/core/java/android/net/INetworkScoreService.aidl
@@ -56,17 +56,26 @@ interface INetworkScoreService
     void disableScoring();
 
     /**
-     * Register a network subsystem for scoring.
+     * Register a cache to receive scoring updates.
      *
      * @param networkType the type of network this cache can handle. See {@link NetworkKey#type}.
      * @param scoreCache implementation of {@link INetworkScoreCache} to store the scores.
      * @throws SecurityException if the caller is not the system.
-     * @throws IllegalArgumentException if a score cache is already registed for this type.
      * @hide
      */
     void registerNetworkScoreCache(int networkType, INetworkScoreCache scoreCache);
 
     /**
+     * Unregister a cache to receive scoring updates.
+     *
+     * @param networkType the type of network this cache can handle. See {@link NetworkKey#type}.
+     * @param scoreCache implementation of {@link INetworkScoreCache} to store the scores.
+     * @throws SecurityException if the caller is not the system.
+     * @hide
+     */
+    void unregisterNetworkScoreCache(int networkType, INetworkScoreCache scoreCache);
+
+    /**
      * Request a recommendation for the best network to connect to
      * taking into account the inputs from the {@link RecommendationRequest}.
      *
diff --git a/core/java/android/net/NetworkScoreManager.java b/core/java/android/net/NetworkScoreManager.java
index c301fe3b73fe..af21cefce7ed 100644
--- a/core/java/android/net/NetworkScoreManager.java
+++ b/core/java/android/net/NetworkScoreManager.java
@@ -279,6 +279,24 @@ public class NetworkScoreManager {
     }
 
     /**
+     * Unregister a network score cache.
+     *
+     * @param networkType the type of network this cache can handle. See {@link NetworkKey#type}.
+     * @param scoreCache implementation of {@link INetworkScoreCache} to store the scores.
+     * @throws SecurityException if the caller does not hold the
+     *         {@link android.Manifest.permission#BROADCAST_NETWORK_PRIVILEGED} permission.
+     * @throws IllegalArgumentException if a score cache is already registered for this type.
+     * @hide
+     */
+    public void unregisterNetworkScoreCache(int networkType, INetworkScoreCache scoreCache) {
+        try {
+            mService.unregisterNetworkScoreCache(networkType, scoreCache);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
      * Request a recommendation for which network to connect to.
      *
      * @param request a {@link RecommendationRequest} instance containing additional