Update tests for PANS network usage metrics

Update existing tests to use new NetworkTemplate/NetworkIdentity
constructors, and add additional tests for new PANS metrics features.

Bug: 175793874
Bug: 174485293
Test: Run the tests in this CL with atest

Change-Id: I6f50993397d886a266874da0047c02022a69f62e

tests/net/java/android/net/NetworkIdentityTest.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net
+
+import android.net.NetworkIdentity.OEM_NONE
+import android.net.NetworkIdentity.OEM_PAID
+import android.net.NetworkIdentity.OEM_PRIVATE
+import android.net.NetworkIdentity.getOemBitfield
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import kotlin.test.assertEquals
+
+@RunWith(JUnit4::class)
+class NetworkIdentityTest {
+    @Test
+    fun testGetOemBitfield() {
+        val oemNone = NetworkCapabilities().apply {
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PAID, false)
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE, false)
+        }
+        val oemPaid = NetworkCapabilities().apply {
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PAID, true)
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE, false)
+        }
+        val oemPrivate = NetworkCapabilities().apply {
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PAID, false)
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE, true)
+        }
+        val oemAll = NetworkCapabilities().apply {
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PAID, true)
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE, true)
+        }
+
+        assertEquals(getOemBitfield(oemNone), OEM_NONE)
+        assertEquals(getOemBitfield(oemPaid), OEM_PAID)
+        assertEquals(getOemBitfield(oemPrivate), OEM_PRIVATE)
+        assertEquals(getOemBitfield(oemAll), OEM_PAID or OEM_PRIVATE)
+    }
+}

tests/net/java/android/net/NetworkTemplateTest.kt

@@ -20,14 +20,23 @@ import android.content.Context
 import android.net.ConnectivityManager.TYPE_MOBILE
 import android.net.ConnectivityManager.TYPE_WIFI
 import android.net.NetworkIdentity.SUBTYPE_COMBINED
+import android.net.NetworkIdentity.OEM_NONE;
+import android.net.NetworkIdentity.OEM_PAID;
+import android.net.NetworkIdentity.OEM_PRIVATE;
 import android.net.NetworkIdentity.buildNetworkIdentity
 import android.net.NetworkStats.DEFAULT_NETWORK_ALL
 import android.net.NetworkStats.METERED_ALL
 import android.net.NetworkStats.ROAMING_ALL
+import android.net.NetworkTemplate.MATCH_ETHERNET
 import android.net.NetworkTemplate.MATCH_MOBILE
+import android.net.NetworkTemplate.MATCH_MOBILE_WILDCARD
 import android.net.NetworkTemplate.MATCH_WIFI
+import android.net.NetworkTemplate.MATCH_WIFI_WILDCARD
 import android.net.NetworkTemplate.NETWORK_TYPE_5G_NSA
 import android.net.NetworkTemplate.NETWORK_TYPE_ALL
+import android.net.NetworkTemplate.OEM_MANAGED_ALL
+import android.net.NetworkTemplate.OEM_MANAGED_NO
+import android.net.NetworkTemplate.OEM_MANAGED_YES
 import android.net.NetworkTemplate.buildTemplateMobileWithRatType
 import android.telephony.TelephonyManager
 import com.android.testutils.assertParcelSane
@@ -37,9 +46,11 @@ import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
 import org.mockito.Mockito.mock
 import org.mockito.MockitoAnnotations
+import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 import kotlin.test.assertNotEquals
 import kotlin.test.assertTrue
+import kotlin.test.fail
 
 private const val TEST_IMSI1 = "imsi1"
 private const val TEST_IMSI2 = "imsi2"
@@ -57,13 +68,18 @@ class NetworkTemplateTest {
     private fun buildNetworkState(
         type: Int,
         subscriberId: String? = null,
-        ssid: String? = null
+        ssid: String? = null,
+        oemManaged: Int = OEM_NONE,
     ): NetworkState {
         val lp = LinkProperties()
         val caps = NetworkCapabilities().apply {
             setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED, false)
             setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING, true)
             setSSID(ssid)
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PAID,
+                    (oemManaged and OEM_PAID) == OEM_PAID)
+            setCapability(NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE,
+                    (oemManaged and OEM_PRIVATE) == OEM_PRIVATE)
         }
         return NetworkState(type, lp, caps, mock(Network::class.java), subscriberId)
     }
@@ -136,11 +152,15 @@ class NetworkTemplateTest {
     @Test
     fun testParcelUnparcel() {
         val templateMobile = NetworkTemplate(MATCH_MOBILE, TEST_IMSI1, null, null, METERED_ALL,
-                ROAMING_ALL, DEFAULT_NETWORK_ALL, TelephonyManager.NETWORK_TYPE_LTE)
+                ROAMING_ALL, DEFAULT_NETWORK_ALL, TelephonyManager.NETWORK_TYPE_LTE,
+                OEM_MANAGED_ALL)
         val templateWifi = NetworkTemplate(MATCH_WIFI, null, null, TEST_SSID1, METERED_ALL,
-                ROAMING_ALL, DEFAULT_NETWORK_ALL, 0)
+                ROAMING_ALL, DEFAULT_NETWORK_ALL, 0, OEM_MANAGED_ALL)
-        assertParcelSane(templateMobile, 8)
+        val templateOem = NetworkTemplate(MATCH_MOBILE, null, null, null, METERED_ALL,
-        assertParcelSane(templateWifi, 8)
+                ROAMING_ALL, DEFAULT_NETWORK_ALL, 0, OEM_MANAGED_YES)
+        assertParcelSane(templateMobile, 9)
+        assertParcelSane(templateWifi, 9)
+        assertParcelSane(templateOem, 9)
     }
 
     // Verify NETWORK_TYPE_* constants in NetworkTemplate do not conflict with
@@ -152,4 +172,81 @@ class NetworkTemplateTest {
             assertNotEquals(NETWORK_TYPE_5G_NSA, ratType)
         }
     }
+
+    @Test
+    fun testOemNetworkConstants() {
+        val constantValues = arrayOf(OEM_MANAGED_YES, OEM_MANAGED_ALL, OEM_MANAGED_NO,
+                OEM_PAID, OEM_PRIVATE, OEM_PAID or OEM_PRIVATE)
+
+        // Verify that "not OEM managed network" constants are equal.
+        assertEquals(OEM_MANAGED_NO, OEM_NONE);
+
+        // Verify the constants don't conflict.
+        assertEquals(constantValues.size, constantValues.distinct().count())
+    }
+
+    /**
+     * Helper to enumerate and assert OEM managed wifi and mobile {@code NetworkTemplate}s match
+     * their the appropriate OEM managed {@code NetworkIdentity}s.
+     *
+     * @param networkType {@code TYPE_MOBILE} or {@code TYPE_WIFI}
+     * @param matchType A match rule from {@code NetworkTemplate.MATCH_*} corresponding to the
+     *         networkType.
+     * @param subscriberId To be populated with {@code TEST_IMSI*} only if networkType is
+     *         {@code TYPE_MOBILE}. May be left as null when matchType is
+     *         {@link NetworkTemplate.MATCH_MOBILE_WILDCARD}.
+     * @param templateSsid Top be populated with {@code TEST_SSID*} only if networkType is
+     *         {@code TYPE_WIFI}. May be left as null when matchType is
+     *         {@link NetworkTemplate.MATCH_WIFI_WILDCARD}.
+     * @param identSsid If networkType is {@code TYPE_WIFI}, this value must *NOT* be null. Provide
+     *         one of {@code TEST_SSID*}.
+     */
+    private fun matchOemManagedIdent(networkType: Int, matchType:Int, subscriberId: String? = null,
+            templateSsid: String? = null, identSsid: String? = null) {
+        val oemManagedStates = arrayOf(OEM_NONE, OEM_PAID, OEM_PRIVATE, OEM_PAID or OEM_PRIVATE)
+        // A null subscriberId needs a null matchSubscriberIds argument as well.
+        val matchSubscriberIds = if (subscriberId == null) null else arrayOf(subscriberId)
+
+        val templateOemYes = NetworkTemplate(matchType, subscriberId, matchSubscriberIds,
+                templateSsid, METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL,
+                OEM_MANAGED_YES)
+        val templateOemAll = NetworkTemplate(matchType, subscriberId, matchSubscriberIds,
+                templateSsid, METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL,
+                OEM_MANAGED_ALL)
+
+        for (identityOemManagedState in oemManagedStates) {
+            val ident = buildNetworkIdentity(mockContext, buildNetworkState(networkType,
+                    subscriberId, identSsid, identityOemManagedState), /*defaultNetwork=*/false,
+                    /*subType=*/0)
+
+            // Create a template with each OEM managed type and match it against the NetworkIdentity
+            for (templateOemManagedState in oemManagedStates) {
+                val template = NetworkTemplate(matchType, subscriberId, matchSubscriberIds,
+                        templateSsid, METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL,
+                        NETWORK_TYPE_ALL, templateOemManagedState)
+                if (identityOemManagedState == templateOemManagedState) {
+                    template.assertMatches(ident)
+                } else {
+                    template.assertDoesNotMatch(ident)
+                }
+            }
+            // OEM_MANAGED_ALL ignores OEM state.
+            templateOemAll.assertMatches(ident)
+            if (identityOemManagedState == OEM_NONE) {
+                // OEM_MANAGED_YES matches everything except OEM_NONE.
+                templateOemYes.assertDoesNotMatch(ident)
+            } else {
+                templateOemYes.assertMatches(ident)
+            }
+        }
+    }
+
+    @Test
+    fun testOemManagedMatchesIdent() {
+        matchOemManagedIdent(TYPE_MOBILE, MATCH_MOBILE, subscriberId = TEST_IMSI1)
+        matchOemManagedIdent(TYPE_MOBILE, MATCH_MOBILE_WILDCARD)
+        matchOemManagedIdent(TYPE_WIFI, MATCH_WIFI, templateSsid = TEST_SSID1,
+                identSsid = TEST_SSID1)
+        matchOemManagedIdent(TYPE_WIFI, MATCH_WIFI_WILDCARD, identSsid = TEST_SSID1)
+    }
 }

tests/net/java/com/android/server/net/NetworkStatsCollectionTest.java

@@ -17,6 +17,7 @@
 package com.android.server.net;
 
 import static android.net.ConnectivityManager.TYPE_MOBILE;
+import static android.net.NetworkIdentity.OEM_NONE;
 import static android.net.NetworkStats.SET_ALL;
 import static android.net.NetworkStats.SET_DEFAULT;
 import static android.net.NetworkStats.TAG_NONE;
@@ -213,7 +214,7 @@ public class NetworkStatsCollectionTest {
         final NetworkStats.Entry entry = new NetworkStats.Entry();
         final NetworkIdentitySet identSet = new NetworkIdentitySet();
         identSet.add(new NetworkIdentity(TYPE_MOBILE, TelephonyManager.NETWORK_TYPE_UNKNOWN,
-                TEST_IMSI, null, false, true, true));
+                TEST_IMSI, null, false, true, true, OEM_NONE));
 
         int myUid = Process.myUid();
         int otherUidInSameUser = Process.myUid() + 1;
@@ -468,7 +469,7 @@ public class NetworkStatsCollectionTest {
         final NetworkStatsCollection large = new NetworkStatsCollection(HOUR_IN_MILLIS);
         final NetworkIdentitySet ident = new NetworkIdentitySet();
         ident.add(new NetworkIdentity(ConnectivityManager.TYPE_MOBILE, -1, TEST_IMSI, null,
-                false, true, true));
+                false, true, true, OEM_NONE));
         large.recordData(ident, UID_ALL, SET_ALL, TAG_NONE, TIME_A, TIME_B,
                 new NetworkStats.Entry(12_730_893_164L, 1, 0, 0, 0));
 

tests/net/java/com/android/server/net/NetworkStatsObserversTest.java

@@ -17,6 +17,7 @@
 package com.android.server.net;
 
 import static android.net.ConnectivityManager.TYPE_MOBILE;
+import static android.net.NetworkIdentity.OEM_NONE;
 import static android.net.NetworkStats.DEFAULT_NETWORK_NO;
 import static android.net.NetworkStats.DEFAULT_NETWORK_YES;
 import static android.net.NetworkStats.METERED_NO;
@@ -220,7 +221,7 @@ public class NetworkStatsObserversTest {
         identSet.add(new NetworkIdentity(
                 TYPE_MOBILE, TelephonyManager.NETWORK_TYPE_UNKNOWN,
                 IMSI_1, null /* networkId */, false /* roaming */, true /* metered */,
-                true /* defaultNetwork */));
+                true /* defaultNetwork */, OEM_NONE));
         return identSet;
     }
 

tests/net/java/com/android/server/net/NetworkStatsServiceTest.java

@@ -21,6 +21,9 @@ import static android.content.Intent.EXTRA_UID;
 import static android.net.ConnectivityManager.TYPE_MOBILE;
 import static android.net.ConnectivityManager.TYPE_VPN;
 import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.net.NetworkIdentity.OEM_NONE;
+import static android.net.NetworkIdentity.OEM_PAID;
+import static android.net.NetworkIdentity.OEM_PRIVATE;
 import static android.net.NetworkStats.DEFAULT_NETWORK_ALL;
 import static android.net.NetworkStats.DEFAULT_NETWORK_NO;
 import static android.net.NetworkStats.DEFAULT_NETWORK_YES;
@@ -40,7 +43,10 @@ import static android.net.NetworkStats.TAG_ALL;
 import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
 import static android.net.NetworkStatsHistory.FIELD_ALL;
+import static android.net.NetworkTemplate.MATCH_MOBILE_WILDCARD;
 import static android.net.NetworkTemplate.NETWORK_TYPE_ALL;
+import static android.net.NetworkTemplate.OEM_MANAGED_NO;
+import static android.net.NetworkTemplate.OEM_MANAGED_YES;
 import static android.net.NetworkTemplate.buildTemplateMobileAll;
 import static android.net.NetworkTemplate.buildTemplateMobileWithRatType;
 import static android.net.NetworkTemplate.buildTemplateWifi;
@@ -643,6 +649,116 @@ public class NetworkStatsServiceTest extends NetworkStatsBaseTest {
         assertUidTotal(template5g, UID_RED, 5L, 13L, 31L, 9L, 2);
     }
 
+    @Test
+    public void testMobileStatsOemManaged() throws Exception {
+        final NetworkTemplate templateOemPaid = new NetworkTemplate(MATCH_MOBILE_WILDCARD,
+                /*subscriberId=*/null, /*matchSubscriberIds=*/null, /*networkId=*/null,
+                METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL, OEM_PAID);
+
+        final NetworkTemplate templateOemPrivate = new NetworkTemplate(MATCH_MOBILE_WILDCARD,
+                /*subscriberId=*/null, /*matchSubscriberIds=*/null, /*networkId=*/null,
+                METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL, OEM_PRIVATE);
+
+        final NetworkTemplate templateOemAll = new NetworkTemplate(MATCH_MOBILE_WILDCARD,
+                /*subscriberId=*/null, /*matchSubscriberIds=*/null, /*networkId=*/null,
+                METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL,
+                OEM_PAID | OEM_PRIVATE);
+
+        final NetworkTemplate templateOemYes = new NetworkTemplate(MATCH_MOBILE_WILDCARD,
+                /*subscriberId=*/null, /*matchSubscriberIds=*/null, /*networkId=*/null,
+                METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL, OEM_MANAGED_YES);
+
+        final NetworkTemplate templateOemNone = new NetworkTemplate(MATCH_MOBILE_WILDCARD,
+                /*subscriberId=*/null, /*matchSubscriberIds=*/null, /*networkId=*/null,
+                METERED_ALL, ROAMING_ALL, DEFAULT_NETWORK_ALL, NETWORK_TYPE_ALL, OEM_MANAGED_NO);
+
+        // OEM_PAID network comes online.
+        NetworkState[] states = new NetworkState[]{buildOemManagedMobileState(IMSI_1, false,
+                new int[]{NetworkCapabilities.NET_CAPABILITY_OEM_PAID})};
+        expectNetworkStatsSummary(buildEmptyStats());
+        expectNetworkStatsUidDetail(buildEmptyStats());
+        mService.forceUpdateIfaces(NETWORKS_MOBILE, states, getActiveIface(states),
+                new UnderlyingNetworkInfo[0]);
+
+        // Create some traffic.
+        incrementCurrentTime(MINUTE_IN_MILLIS);
+        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
+                .addEntry(new NetworkStats.Entry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE,
+                        36L, 41L, 24L, 96L, 0L)));
+        forcePollAndWaitForIdle();
+
+        // OEM_PRIVATE network comes online.
+        states = new NetworkState[]{buildOemManagedMobileState(IMSI_1, false,
+                new int[]{NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE})};
+        expectNetworkStatsSummary(buildEmptyStats());
+        expectNetworkStatsUidDetail(buildEmptyStats());
+        mService.forceUpdateIfaces(NETWORKS_MOBILE, states, getActiveIface(states),
+                new UnderlyingNetworkInfo[0]);
+
+        // Create some traffic.
+        incrementCurrentTime(MINUTE_IN_MILLIS);
+        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
+                .addEntry(new NetworkStats.Entry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE,
+                        49L, 71L, 72L, 48L, 0L)));
+        forcePollAndWaitForIdle();
+
+        // OEM_PAID + OEM_PRIVATE network comes online.
+        states = new NetworkState[]{buildOemManagedMobileState(IMSI_1, false,
+                new int[]{NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE,
+                          NetworkCapabilities.NET_CAPABILITY_OEM_PAID})};
+        expectNetworkStatsSummary(buildEmptyStats());
+        expectNetworkStatsUidDetail(buildEmptyStats());
+        mService.forceUpdateIfaces(NETWORKS_MOBILE, states, getActiveIface(states),
+                new UnderlyingNetworkInfo[0]);
+
+        // Create some traffic.
+        incrementCurrentTime(MINUTE_IN_MILLIS);
+        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
+                .addEntry(new NetworkStats.Entry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE,
+                        57L, 86L, 83L, 93L, 0L)));
+        forcePollAndWaitForIdle();
+
+        // OEM_NONE network comes online.
+        states = new NetworkState[]{buildOemManagedMobileState(IMSI_1, false, new int[]{})};
+        expectNetworkStatsSummary(buildEmptyStats());
+        expectNetworkStatsUidDetail(buildEmptyStats());
+        mService.forceUpdateIfaces(NETWORKS_MOBILE, states, getActiveIface(states),
+                new UnderlyingNetworkInfo[0]);
+
+        // Create some traffic.
+        incrementCurrentTime(MINUTE_IN_MILLIS);
+        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
+                .addEntry(new NetworkStats.Entry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE,
+                        29L, 73L, 34L, 31L, 0L)));
+        forcePollAndWaitForIdle();
+
+        // Verify OEM_PAID template gets only relevant stats.
+        assertUidTotal(templateOemPaid, UID_RED, 36L, 41L, 24L, 96L, 0);
+
+        // Verify OEM_PRIVATE template gets only relevant stats.
+        assertUidTotal(templateOemPrivate, UID_RED, 49L, 71L, 72L, 48L, 0);
+
+        // Verify OEM_PAID + OEM_PRIVATE template gets only relevant stats.
+        assertUidTotal(templateOemAll, UID_RED, 57L, 86L, 83L, 93L, 0);
+
+        // Verify OEM_NONE sees only non-OEM managed stats.
+        assertUidTotal(templateOemNone, UID_RED, 29L, 73L, 34L, 31L, 0);
+
+        // Verify OEM_MANAGED_YES sees all OEM managed stats.
+        assertUidTotal(templateOemYes, UID_RED,
+                36L + 49L + 57L,
+                41L + 71L + 86L,
+                24L + 72L + 83L,
+                96L + 48L + 93L, 0);
+
+        // Verify ALL_MOBILE template gets both OEM managed and non-OEM managed stats.
+        assertUidTotal(sTemplateImsi1, UID_RED,
+                36L + 49L + 57L + 29L,
+                41L + 71L + 86L + 73L,
+                24L + 72L + 83L + 34L,
+                96L + 48L + 93L + 31L, 0);
+    }
+
     // TODO: support per IMSI state
     private void setMobileRatTypeAndWaitForIdle(int ratType) {
         when(mNetworkStatsSubscriptionsMonitor.getRatTypeForSubscriberId(anyString()))
@@ -1488,6 +1604,20 @@ public class NetworkStatsServiceTest extends NetworkStatsBaseTest {
         return new NetworkState(TYPE_VPN, prop, new NetworkCapabilities(), VPN_NETWORK, null);
     }
 
+    private static NetworkState buildOemManagedMobileState(String subscriberId, boolean isRoaming,
+                int[] oemNetCapabilities) {
+        final LinkProperties prop = new LinkProperties();
+        prop.setInterfaceName(TEST_IFACE);
+        final NetworkCapabilities capabilities = new NetworkCapabilities();
+        capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED, false);
+        capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING, !isRoaming);
+        for (int nc : oemNetCapabilities) {
+            capabilities.setCapability(nc, true);
+        }
+        capabilities.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR);
+        return new NetworkState(TYPE_MOBILE, prop, capabilities, MOBILE_NETWORK, subscriberId);
+    }
+
     private long getElapsedRealtime() {
         return mElapsedRealtime;
     }