[SP21] Address comments for API council review about aosp/1172143

Test: atest FrameworksNetTests ImsPhoneCallTrackerTest
Test: atest TetheringTests NetworkStackTests
Test: m doc-comment-check-docs
Fix: 148552904

Change-Id: I141393f229e772d2eb9f7c156849e379bd71b845
Merged-In: I141393f229e772d2eb9f7c156849e379bd71b845
(cherry picked from aosp/1253717)
diff --git a/Tethering/src/com/android/server/connectivity/tethering/OffloadController.java b/Tethering/src/com/android/server/connectivity/tethering/OffloadController.java
index a402ffa..d43c5c6 100644
--- a/Tethering/src/com/android/server/connectivity/tethering/OffloadController.java
+++ b/Tethering/src/com/android/server/connectivity/tethering/OffloadController.java
@@ -39,8 +39,7 @@
 import android.net.netlink.ConntrackMessage;
 import android.net.netlink.NetlinkConstants;
 import android.net.netlink.NetlinkSocket;
-import android.net.netstats.provider.AbstractNetworkStatsProvider;
-import android.net.netstats.provider.NetworkStatsProviderCallback;
+import android.net.netstats.provider.NetworkStatsProvider;
 import android.net.util.SharedLog;
 import android.os.Handler;
 import android.provider.Settings;
@@ -89,8 +88,8 @@
     private final Handler mHandler;
     private final OffloadHardwareInterface mHwInterface;
     private final ContentResolver mContentResolver;
-    private final @NonNull OffloadTetheringStatsProvider mStatsProvider;
-    private final @Nullable NetworkStatsProviderCallback mStatsProviderCb;
+    @Nullable
+    private final OffloadTetheringStatsProvider mStatsProvider;
     private final SharedLog mLog;
     private final HashMap<String, LinkProperties> mDownstreams;
     private boolean mConfigInitialized;
@@ -124,19 +123,18 @@
         mHandler = h;
         mHwInterface = hwi;
         mContentResolver = contentResolver;
-        mStatsProvider = new OffloadTetheringStatsProvider();
         mLog = log.forSubComponent(TAG);
         mDownstreams = new HashMap<>();
         mExemptPrefixes = new HashSet<>();
         mLastLocalPrefixStrs = new HashSet<>();
-        NetworkStatsProviderCallback providerCallback = null;
+        OffloadTetheringStatsProvider provider = new OffloadTetheringStatsProvider();
         try {
-            providerCallback = nsm.registerNetworkStatsProvider(
-                    getClass().getSimpleName(), mStatsProvider);
+            nsm.registerNetworkStatsProvider(getClass().getSimpleName(), provider);
         } catch (RuntimeException e) {
             Log.wtf(TAG, "Cannot register offload stats provider: " + e);
+            provider = null;
         }
-        mStatsProviderCb = providerCallback;
+        mStatsProvider = provider;
     }
 
     /** Start hardware offload. */
@@ -185,7 +183,7 @@
                         // and we need to synchronize stats and limits between
                         // software and hardware forwarding.
                         updateStatsForAllUpstreams();
-                        mStatsProvider.pushTetherStats();
+                        if (mStatsProvider != null) mStatsProvider.pushTetherStats();
                     }
 
                     @Override
@@ -198,7 +196,7 @@
                         // limits set take into account any software tethering
                         // traffic that has been happening in the meantime.
                         updateStatsForAllUpstreams();
-                        mStatsProvider.pushTetherStats();
+                        if (mStatsProvider != null) mStatsProvider.pushTetherStats();
                         // [2] (Re)Push all state.
                         computeAndPushLocalPrefixes(UpdateType.FORCE);
                         pushAllDownstreamState();
@@ -217,10 +215,12 @@
                         // TODO: rev the HAL so that it provides an interface name.
 
                         updateStatsForCurrentUpstream();
-                        mStatsProvider.pushTetherStats();
-                        // Push stats to service does not cause the service react to it immediately.
-                        // Inform the service about limit reached.
-                        if (mStatsProviderCb != null) mStatsProviderCb.onLimitReached();
+                        if (mStatsProvider != null) {
+                            mStatsProvider.pushTetherStats();
+                            // Push stats to service does not cause the service react to it
+                            // immediately. Inform the service about limit reached.
+                            mStatsProvider.notifyLimitReached();
+                        }
                     }
 
                     @Override
@@ -263,13 +263,17 @@
     }
 
     @VisibleForTesting
-    class OffloadTetheringStatsProvider extends AbstractNetworkStatsProvider {
+    class OffloadTetheringStatsProvider extends NetworkStatsProvider {
         // These stats must only ever be touched on the handler thread.
         @NonNull
         private NetworkStats mIfaceStats = new NetworkStats(0L, 0);
         @NonNull
         private NetworkStats mUidStats = new NetworkStats(0L, 0);
 
+        /**
+         * A helper function that collect tether stats from local hashmap. Note that this does not
+         * invoke binder call.
+         */
         @VisibleForTesting
         @NonNull
         NetworkStats getTetherStats(@NonNull StatsType how) {
@@ -287,7 +291,7 @@
         }
 
         @Override
-        public void setLimit(String iface, long quotaBytes) {
+        public void onSetLimit(String iface, long quotaBytes) {
             // Listen for all iface is necessary since upstream might be changed after limit
             // is set.
             mHandler.post(() -> {
@@ -315,13 +319,12 @@
          */
         public void pushTetherStats() {
             // TODO: remove the accumulated stats and report the diff from HAL directly.
-            if (null == mStatsProviderCb) return;
             final NetworkStats ifaceDiff =
                     getTetherStats(StatsType.STATS_PER_IFACE).subtract(mIfaceStats);
             final NetworkStats uidDiff =
                     getTetherStats(StatsType.STATS_PER_UID).subtract(mUidStats);
             try {
-                mStatsProviderCb.onStatsUpdated(0 /* token */, ifaceDiff, uidDiff);
+                notifyStatsUpdated(0 /* token */, ifaceDiff, uidDiff);
                 mIfaceStats = mIfaceStats.add(ifaceDiff);
                 mUidStats = mUidStats.add(uidDiff);
             } catch (RuntimeException e) {
@@ -330,7 +333,7 @@
         }
 
         @Override
-        public void requestStatsUpdate(int token) {
+        public void onRequestStatsUpdate(int token) {
             // Do not attempt to update stats by querying the offload HAL
             // synchronously from a different thread than the Handler thread. http://b/64771555.
             mHandler.post(() -> {
@@ -340,7 +343,7 @@
         }
 
         @Override
-        public void setAlert(long quotaBytes) {
+        public void onSetAlert(long quotaBytes) {
             // TODO: Ask offload HAL to notify alert without stopping traffic.
         }
     }
diff --git a/Tethering/tests/unit/src/com/android/server/connectivity/tethering/OffloadControllerTest.java b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/OffloadControllerTest.java
index 7e62e5a..1d100e6 100644
--- a/Tethering/tests/unit/src/com/android/server/connectivity/tethering/OffloadControllerTest.java
+++ b/Tethering/tests/unit/src/com/android/server/connectivity/tethering/OffloadControllerTest.java
@@ -33,6 +33,8 @@
 import static com.android.testutils.MiscAssertsKt.assertThrows;
 import static com.android.testutils.NetworkStatsUtilsKt.orderInsensitiveEquals;
 
+import static junit.framework.Assert.assertNotNull;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyInt;
@@ -61,8 +63,7 @@
 import android.net.NetworkStats;
 import android.net.NetworkStats.Entry;
 import android.net.RouteInfo;
-import android.net.netstats.provider.AbstractNetworkStatsProvider;
-import android.net.netstats.provider.NetworkStatsProviderCallback;
+import android.net.netstats.provider.INetworkStatsProviderCallback;
 import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.Looper;
@@ -108,12 +109,10 @@
     @Mock private ApplicationInfo mApplicationInfo;
     @Mock private Context mContext;
     @Mock private NetworkStatsManager mStatsManager;
-    @Mock private NetworkStatsProviderCallback mTetherStatsProviderCb;
+    @Mock private INetworkStatsProviderCallback mTetherStatsProviderCb;
+    private OffloadController.OffloadTetheringStatsProvider mTetherStatsProvider;
     private final ArgumentCaptor<ArrayList> mStringArrayCaptor =
             ArgumentCaptor.forClass(ArrayList.class);
-    private final ArgumentCaptor<OffloadController.OffloadTetheringStatsProvider>
-            mTetherStatsProviderCaptor =
-            ArgumentCaptor.forClass(OffloadController.OffloadTetheringStatsProvider.class);
     private final ArgumentCaptor<OffloadHardwareInterface.ControlCallback> mControlCallbackCaptor =
             ArgumentCaptor.forClass(OffloadHardwareInterface.ControlCallback.class);
     private MockContentResolver mContentResolver;
@@ -126,8 +125,6 @@
         mContentResolver.addProvider(Settings.AUTHORITY, new FakeSettingsProvider());
         when(mContext.getContentResolver()).thenReturn(mContentResolver);
         FakeSettingsProvider.clearSettingsProvider();
-        when(mStatsManager.registerNetworkStatsProvider(anyString(), any()))
-                .thenReturn(mTetherStatsProviderCb);
     }
 
     @After public void tearDown() throws Exception {
@@ -154,8 +151,14 @@
     private OffloadController makeOffloadController() throws Exception {
         OffloadController offload = new OffloadController(new Handler(Looper.getMainLooper()),
                 mHardware, mContentResolver, mStatsManager, new SharedLog("test"));
+        final ArgumentCaptor<OffloadController.OffloadTetheringStatsProvider>
+                tetherStatsProviderCaptor =
+                ArgumentCaptor.forClass(OffloadController.OffloadTetheringStatsProvider.class);
         verify(mStatsManager).registerNetworkStatsProvider(anyString(),
-                mTetherStatsProviderCaptor.capture());
+                tetherStatsProviderCaptor.capture());
+        mTetherStatsProvider = tetherStatsProviderCaptor.getValue();
+        assertNotNull(mTetherStatsProvider);
+        mTetherStatsProvider.setProviderCallbackBinder(mTetherStatsProviderCb);
         return offload;
     }
 
@@ -413,9 +416,6 @@
         final OffloadController offload = makeOffloadController();
         offload.start();
 
-        final OffloadController.OffloadTetheringStatsProvider provider =
-                mTetherStatsProviderCaptor.getValue();
-
         final String ethernetIface = "eth1";
         final String mobileIface = "rmnet_data0";
 
@@ -443,8 +443,8 @@
         inOrder.verify(mHardware, times(1)).getForwardedStats(eq(mobileIface));
 
         // Verify that the fetched stats are stored.
-        final NetworkStats ifaceStats = provider.getTetherStats(STATS_PER_IFACE);
-        final NetworkStats uidStats = provider.getTetherStats(STATS_PER_UID);
+        final NetworkStats ifaceStats = mTetherStatsProvider.getTetherStats(STATS_PER_IFACE);
+        final NetworkStats uidStats = mTetherStatsProvider.getTetherStats(STATS_PER_UID);
         final NetworkStats expectedIfaceStats = new NetworkStats(0L, 2)
                 .addValues(buildTestEntry(STATS_PER_IFACE, mobileIface, 999, 99999))
                 .addValues(buildTestEntry(STATS_PER_IFACE, ethernetIface, 12345, 54321));
@@ -462,13 +462,12 @@
                 NetworkStats.class);
 
         // Force pushing stats update to verify the stats reported.
-        provider.pushTetherStats();
-        verify(mTetherStatsProviderCb, times(1)).onStatsUpdated(anyInt(),
-                ifaceStatsCaptor.capture(), uidStatsCaptor.capture());
+        mTetherStatsProvider.pushTetherStats();
+        verify(mTetherStatsProviderCb, times(1))
+                .notifyStatsUpdated(anyInt(), ifaceStatsCaptor.capture(), uidStatsCaptor.capture());
         assertTrue(orderInsensitiveEquals(expectedIfaceStats, ifaceStatsCaptor.getValue()));
         assertTrue(orderInsensitiveEquals(expectedUidStats, uidStatsCaptor.getValue()));
 
-
         when(mHardware.getForwardedStats(eq(ethernetIface))).thenReturn(
                 new ForwardedStats(100000, 100000));
         offload.setUpstreamLinkProperties(null);
@@ -483,8 +482,8 @@
         inOrder.verifyNoMoreInteractions();
 
         // Verify that the stored stats is accumulated.
-        final NetworkStats ifaceStatsAccu = provider.getTetherStats(STATS_PER_IFACE);
-        final NetworkStats uidStatsAccu = provider.getTetherStats(STATS_PER_UID);
+        final NetworkStats ifaceStatsAccu = mTetherStatsProvider.getTetherStats(STATS_PER_IFACE);
+        final NetworkStats uidStatsAccu = mTetherStatsProvider.getTetherStats(STATS_PER_UID);
         final NetworkStats expectedIfaceStatsAccu = new NetworkStats(0L, 2)
                 .addValues(buildTestEntry(STATS_PER_IFACE, mobileIface, 999, 99999))
                 .addValues(buildTestEntry(STATS_PER_IFACE, ethernetIface, 112345, 154321));
@@ -498,7 +497,7 @@
 
         // Verify that only diff of stats is reported.
         reset(mTetherStatsProviderCb);
-        provider.pushTetherStats();
+        mTetherStatsProvider.pushTetherStats();
         final NetworkStats expectedIfaceStatsDiff = new NetworkStats(0L, 2)
                 .addValues(buildTestEntry(STATS_PER_IFACE, mobileIface, 0, 0))
                 .addValues(buildTestEntry(STATS_PER_IFACE, ethernetIface, 100000, 100000));
@@ -506,8 +505,8 @@
         final NetworkStats expectedUidStatsDiff = new NetworkStats(0L, 2)
                 .addValues(buildTestEntry(STATS_PER_UID, mobileIface, 0, 0))
                 .addValues(buildTestEntry(STATS_PER_UID, ethernetIface, 100000, 100000));
-        verify(mTetherStatsProviderCb, times(1)).onStatsUpdated(anyInt(),
-                ifaceStatsCaptor.capture(), uidStatsCaptor.capture());
+        verify(mTetherStatsProviderCb, times(1))
+                .notifyStatsUpdated(anyInt(), ifaceStatsCaptor.capture(), uidStatsCaptor.capture());
         assertTrue(orderInsensitiveEquals(expectedIfaceStatsDiff, ifaceStatsCaptor.getValue()));
         assertTrue(orderInsensitiveEquals(expectedUidStatsDiff, uidStatsCaptor.getValue()));
     }
@@ -529,19 +528,18 @@
         lp.setInterfaceName(ethernetIface);
         offload.setUpstreamLinkProperties(lp);
 
-        AbstractNetworkStatsProvider provider = mTetherStatsProviderCaptor.getValue();
         final InOrder inOrder = inOrder(mHardware);
         when(mHardware.setUpstreamParameters(any(), any(), any(), any())).thenReturn(true);
         when(mHardware.setDataLimit(anyString(), anyLong())).thenReturn(true);
 
         // Applying an interface quota to the current upstream immediately sends it to the hardware.
-        provider.setLimit(ethernetIface, ethernetLimit);
+        mTetherStatsProvider.onSetLimit(ethernetIface, ethernetLimit);
         waitForIdle();
         inOrder.verify(mHardware).setDataLimit(ethernetIface, ethernetLimit);
         inOrder.verifyNoMoreInteractions();
 
         // Applying an interface quota to another upstream does not take any immediate action.
-        provider.setLimit(mobileIface, mobileLimit);
+        mTetherStatsProvider.onSetLimit(mobileIface, mobileLimit);
         waitForIdle();
         inOrder.verify(mHardware, never()).setDataLimit(anyString(), anyLong());
 
@@ -554,7 +552,7 @@
 
         // Setting a limit of ITetheringStatsProvider.QUOTA_UNLIMITED causes the limit to be set
         // to Long.MAX_VALUE.
-        provider.setLimit(mobileIface, ITetheringStatsProvider.QUOTA_UNLIMITED);
+        mTetherStatsProvider.onSetLimit(mobileIface, ITetheringStatsProvider.QUOTA_UNLIMITED);
         waitForIdle();
         inOrder.verify(mHardware).setDataLimit(mobileIface, Long.MAX_VALUE);
 
@@ -562,7 +560,7 @@
         when(mHardware.setUpstreamParameters(any(), any(), any(), any())).thenReturn(false);
         lp.setInterfaceName(ethernetIface);
         offload.setUpstreamLinkProperties(lp);
-        provider.setLimit(mobileIface, mobileLimit);
+        mTetherStatsProvider.onSetLimit(mobileIface, mobileLimit);
         waitForIdle();
         inOrder.verify(mHardware, never()).setDataLimit(anyString(), anyLong());
 
@@ -571,7 +569,7 @@
         when(mHardware.setDataLimit(anyString(), anyLong())).thenReturn(false);
         lp.setInterfaceName(mobileIface);
         offload.setUpstreamLinkProperties(lp);
-        provider.setLimit(mobileIface, mobileLimit);
+        mTetherStatsProvider.onSetLimit(mobileIface, mobileLimit);
         waitForIdle();
         inOrder.verify(mHardware).getForwardedStats(ethernetIface);
         inOrder.verify(mHardware).stopOffloadControl();
@@ -587,7 +585,7 @@
 
         OffloadHardwareInterface.ControlCallback callback = mControlCallbackCaptor.getValue();
         callback.onStoppedLimitReached();
-        verify(mTetherStatsProviderCb, times(1)).onStatsUpdated(anyInt(), any(), any());
+        verify(mTetherStatsProviderCb, times(1)).notifyStatsUpdated(anyInt(), any(), any());
     }
 
     @Test
@@ -691,7 +689,7 @@
         verify(mHardware, times(1)).getForwardedStats(eq(RMNET0));
         verify(mHardware, times(1)).getForwardedStats(eq(WLAN0));
         // TODO: verify the exact stats reported.
-        verify(mTetherStatsProviderCb, times(1)).onStatsUpdated(anyInt(), any(), any());
+        verify(mTetherStatsProviderCb, times(1)).notifyStatsUpdated(anyInt(), any(), any());
         verifyNoMoreInteractions(mTetherStatsProviderCb);
         verifyNoMoreInteractions(mHardware);
     }
@@ -756,7 +754,7 @@
         // Verify forwarded stats behaviour.
         verify(mHardware, times(1)).getForwardedStats(eq(RMNET0));
         verify(mHardware, times(1)).getForwardedStats(eq(WLAN0));
-        verify(mTetherStatsProviderCb, times(1)).onStatsUpdated(anyInt(), any(), any());
+        verify(mTetherStatsProviderCb, times(1)).notifyStatsUpdated(anyInt(), any(), any());
         verifyNoMoreInteractions(mTetherStatsProviderCb);
 
         // TODO: verify local prefixes and downstreams are also pushed to the HAL.