Merge "Adjust polling interval for auto on/off keepalives"

service/src/com/android/server/connectivity/AutomaticOnOffKeepaliveTracker.java

@@ -18,6 +18,7 @@ package com.android.server.connectivity;
 
 import static android.net.NetworkAgent.CMD_START_SOCKET_KEEPALIVE;
 import static android.net.SocketKeepalive.ERROR_INVALID_SOCKET;
+import static android.net.SocketKeepalive.MIN_INTERVAL_SEC;
 import static android.net.SocketKeepalive.SUCCESS_PAUSED;
 import static android.provider.DeviceConfig.NAMESPACE_TETHERING;
 import static android.system.OsConstants.AF_INET;
@@ -88,8 +89,8 @@ import java.util.Objects;
 public class AutomaticOnOffKeepaliveTracker {
     private static final String TAG = "AutomaticOnOffKeepaliveTracker";
     private static final int[] ADDRESS_FAMILIES = new int[] {AF_INET6, AF_INET};
-    private static final long DEFAULT_TCP_POLLING_INTERVAL_MS = 120_000L;
     private static final long LOW_TCP_POLLING_INTERVAL_MS = 1_000L;
+    private static final int ADJUST_TCP_POLLING_DELAY_MS = 2000;
     private static final String AUTOMATIC_ON_OFF_KEEPALIVE_VERSION =
             "automatic_on_off_keepalive_version";
     /**
@@ -280,12 +281,14 @@ public class AutomaticOnOffKeepaliveTracker {
         mAlarmManager = mDependencies.getAlarmManager(context);
     }
 
-    private void startTcpPollingAlarm(@NonNull final AlarmManager.OnAlarmListener listener) {
+    private void startTcpPollingAlarm(@NonNull AutomaticOnOffKeepalive ki) {
+        if (ki.mAlarmListener == null) return;
+
         final long triggerAtMillis =
-                SystemClock.elapsedRealtime() + getTcpPollingInterval();
+                mDependencies.getElapsedRealtime() + getTcpPollingIntervalMs(ki);
         // Setup a non-wake up alarm.
         mAlarmManager.setExact(AlarmManager.ELAPSED_REALTIME, triggerAtMillis, null /* tag */,
-                listener, mConnectivityServiceHandler);
+                ki.mAlarmListener, mConnectivityServiceHandler);
     }
 
     /**
@@ -322,7 +325,7 @@ public class AutomaticOnOffKeepaliveTracker {
             handleMaybeResumeKeepalive(ki);
         }
         // TODO: listen to socket status instead of periodically check.
-        startTcpPollingAlarm(ki.mAlarmListener);
+        startTcpPollingAlarm(ki);
     }
 
     /**
@@ -402,7 +405,7 @@ public class AutomaticOnOffKeepaliveTracker {
         }
         mAutomaticOnOffKeepalives.add(autoKi);
         if (STATE_ALWAYS_ON != autoKi.mAutomaticOnOffState) {
-            startTcpPollingAlarm(autoKi.mAlarmListener);
+            startTcpPollingAlarm(autoKi);
         }
     }
 
@@ -677,9 +680,15 @@ public class AutomaticOnOffKeepaliveTracker {
         }
     }
 
-    private long getTcpPollingInterval() {
+    private long getTcpPollingIntervalMs(@NonNull AutomaticOnOffKeepalive ki) {
         final boolean useLowTimer = mTestLowTcpPollingTimerUntilMs > System.currentTimeMillis();
-        return useLowTimer ? LOW_TCP_POLLING_INTERVAL_MS : DEFAULT_TCP_POLLING_INTERVAL_MS;
+        // Adjust the polling interval to be smaller than the keepalive delay to preserve
+        // some time for the system to restart the keepalive.
+        final int timer = ki.mKi.getKeepaliveIntervalSec() * 1000 - ADJUST_TCP_POLLING_DELAY_MS;
+        if (timer < MIN_INTERVAL_SEC) {
+            Log.wtf(TAG, "Unreasonably low keepalive delay: " + ki.mKi.getKeepaliveIntervalSec());
+        }
+        return useLowTimer ? LOW_TCP_POLLING_INTERVAL_MS : Math.max(timer, MIN_INTERVAL_SEC);
     }
 
     /**
@@ -786,5 +795,14 @@ public class AutomaticOnOffKeepaliveTracker {
             return DeviceConfigUtils.isFeatureEnabled(mContext, NAMESPACE_TETHERING, name,
                     defaultEnabled);
         }
+
+        /**
+         * Returns milliseconds since boot, including time spent in sleep.
+         *
+         * @return elapsed milliseconds since boot.
+         */
+        public long getElapsedRealtime() {
+            return SystemClock.elapsedRealtime();
+        }
     }
 }

service/src/com/android/server/connectivity/KeepaliveTracker.java

@@ -264,6 +264,10 @@ public class KeepaliveTracker {
             return mSlot;
         }
 
+        int getKeepaliveIntervalSec() {
+            return mInterval;
+        }
+
         private int checkNetworkConnected() {
             if (!mNai.networkInfo.isConnectedOrConnecting()) {
                 return ERROR_INVALID_NETWORK;

tests/unit/java/com/android/server/connectivity/AutomaticOnOffKeepaliveTrackerTest.java

@@ -28,8 +28,8 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.longThat;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
@@ -57,6 +57,7 @@ import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.Message;
+import android.os.SystemClock;
 import android.test.suitebuilder.annotation.SmallTest;
 import android.util.Log;
 
@@ -94,6 +95,7 @@ public class AutomaticOnOffKeepaliveTrackerTest {
     private static final int NETID_MASK = 0xffff;
     private static final int TIMEOUT_MS = 30_000;
     private static final int MOCK_RESOURCE_ID = 5;
+    private static final int TEST_KEEPALIVE_INTERVAL_SEC = 10;
     private AutomaticOnOffKeepaliveTracker mAOOKeepaliveTracker;
     private HandlerThread mHandlerThread;
 
@@ -334,9 +336,13 @@ public class AutomaticOnOffKeepaliveTrackerTest {
         final KeepalivePacketData kpd = new NattKeepalivePacketData(srcAddress, srcPort,
                 dstAddress, dstPort, new byte[] {1});
         final KeepaliveInfo ki = mKeepaliveTracker.new KeepaliveInfo(cb, nai, kpd,
-                10 /* interval */, KeepaliveInfo.TYPE_NATT, fd);
+                TEST_KEEPALIVE_INTERVAL_SEC, KeepaliveInfo.TYPE_NATT, fd);
         mKeepaliveTracker.setReturnedKeepaliveInfo(ki);
 
+        // Mock elapsed real time to verify the alarm timer.
+        final long time = SystemClock.elapsedRealtime();
+        doReturn(time).when(mDependencies).getElapsedRealtime();
+
         mAOOKeepaliveTracker.startNattKeepalive(nai, fd, 10 /* intervalSeconds */, cb,
                 srcAddress.toString(), srcPort, dstAddress.toString(), dstPort,
                 true /* automaticOnOffKeepalives */, underpinnedNetwork);
@@ -344,8 +350,11 @@ public class AutomaticOnOffKeepaliveTrackerTest {
 
         final ArgumentCaptor<AlarmManager.OnAlarmListener> listenerCaptor =
                 ArgumentCaptor.forClass(AlarmManager.OnAlarmListener.class);
-        verify(mAlarmManager).setExact(eq(AlarmManager.ELAPSED_REALTIME), anyLong(),
+        // The alarm timer should be smaller than the keepalive delay. Verify the alarm trigger time
-                any(), listenerCaptor.capture(), eq(mTestHandler));
+        // is higher than base time but smaller than the keepalive delay.
+        verify(mAlarmManager).setExact(eq(AlarmManager.ELAPSED_REALTIME),
+                longThat(t -> t > time + 1000L && t < time + TEST_KEEPALIVE_INTERVAL_SEC * 1000L),
+                any() /* tag */, listenerCaptor.capture(), eq(mTestHandler));
         final AlarmManager.OnAlarmListener listener = listenerCaptor.getValue();
 
         // For realism, the listener should be posted on the handler