Don't rematch all requests when adding new ones
With the network selection rewrite in S, rematching a single request can
now easily be done; this can be used as an optimization in
handleRegisterNetworkRequests to avoid rematching all requests when
registering a new one.
This can be disabled by a flag that is unset by default,
REMATCH_ALL_REQUESTS_ON_REGISTER.
Test: atest ConnectivityServiceTest
Change-Id: If76f79b41ac88863974f7025624667134bea2570
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index b6240c4..dd0d567 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -23,6 +23,8 @@
import static android.net.ConnectivityManager.TYPE_MOBILE_HIPRI;
import static android.provider.DeviceConfig.NAMESPACE_CONNECTIVITY;
+import static com.android.net.module.util.DeviceConfigUtils.TETHERING_MODULE_NAME;
+
import android.content.ContentResolver;
import android.content.Context;
import android.content.res.Resources;
@@ -60,8 +62,6 @@
private static final String[] EMPTY_STRING_ARRAY = new String[0];
- private static final String TETHERING_MODULE_NAME = "com.android.tethering";
-
// Default ranges used for the legacy DHCP server.
// USB is 192.168.42.1 and 255.255.255.0
// Wifi is 192.168.43.1 and 255.255.255.0
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 9e88890..222f5c8 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -87,9 +87,12 @@
import static android.net.shared.NetworkMonitorUtils.isPrivateDnsValidationRequired;
import static android.os.Process.INVALID_UID;
import static android.os.Process.VPN_UID;
+import static android.provider.DeviceConfig.NAMESPACE_CONNECTIVITY;
import static android.system.OsConstants.IPPROTO_TCP;
import static android.system.OsConstants.IPPROTO_UDP;
+import static com.android.net.module.util.DeviceConfigUtils.TETHERING_MODULE_NAME;
+
import static java.util.Map.Entry;
import android.Manifest;
@@ -232,6 +235,7 @@
import com.android.modules.utils.build.SdkLevel;
import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
import com.android.net.module.util.CollectionUtils;
+import com.android.net.module.util.DeviceConfigUtils;
import com.android.net.module.util.LinkPropertiesUtils.CompareOrUpdateResult;
import com.android.net.module.util.LinkPropertiesUtils.CompareResult;
import com.android.net.module.util.LocationPermissionChecker;
@@ -239,6 +243,7 @@
import com.android.net.module.util.PermissionUtils;
import com.android.net.module.util.netlink.InetDiagMessage;
import com.android.server.connectivity.AutodestructReference;
+import com.android.server.connectivity.ConnectivityFlags;
import com.android.server.connectivity.DnsManager;
import com.android.server.connectivity.DnsManager.PrivateDnsValidationUpdate;
import com.android.server.connectivity.FullScore;
@@ -371,6 +376,7 @@
// The Context is created for UserHandle.ALL.
private final Context mUserAllContext;
private final Dependencies mDeps;
+ private final ConnectivityFlags mFlags;
// 0 is full bad, 100 is full good
private int mDefaultInetConditionPublished = 0;
@@ -1309,6 +1315,14 @@
public LocationPermissionChecker makeLocationPermissionChecker(Context context) {
return new LocationPermissionChecker(context);
}
+
+ /**
+ * @see DeviceConfigUtils#isFeatureEnabled
+ */
+ public boolean isFeatureEnabled(Context context, String name, boolean defaultEnabled) {
+ return DeviceConfigUtils.isFeatureEnabled(context, NAMESPACE_CONNECTIVITY, name,
+ TETHERING_MODULE_NAME, defaultEnabled);
+ }
}
public ConnectivityService(Context context) {
@@ -1323,6 +1337,7 @@
if (DBG) log("ConnectivityService starting up");
mDeps = Objects.requireNonNull(deps, "missing Dependencies");
+ mFlags = new ConnectivityFlags();
mSystemProperties = mDeps.getSystemProperties();
mNetIdManager = mDeps.makeNetIdManager();
mContext = Objects.requireNonNull(context, "missing Context");
@@ -2790,6 +2805,9 @@
*/
@VisibleForTesting
public void systemReadyInternal() {
+ // Load flags after PackageManager is ready to query module version
+ mFlags.loadFlags(mDeps, mContext);
+
// Since mApps in PermissionMonitor needs to be populated first to ensure that
// listening network request which is sent by MultipathPolicyTracker won't be added
// NET_CAPABILITY_FOREGROUND capability. Thus, MultipathPolicyTracker.start() must
@@ -4101,7 +4119,11 @@
}
}
- rematchAllNetworksAndRequests();
+ if (mFlags.noRematchAllRequestsOnRegister()) {
+ rematchNetworksAndRequests(nris);
+ } else {
+ rematchAllNetworksAndRequests();
+ }
// Requests that have not been matched to a network will not have been sent to the
// providers, because the old satisfier and the new satisfier are the same (null in this
diff --git a/service/src/com/android/server/connectivity/ConnectivityFlags.java b/service/src/com/android/server/connectivity/ConnectivityFlags.java
new file mode 100644
index 0000000..122ea1c
--- /dev/null
+++ b/service/src/com/android/server/connectivity/ConnectivityFlags.java
@@ -0,0 +1,66 @@
+/*
+ * 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 com.android.server.connectivity;
+
+import android.content.Context;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.ConnectivityService;
+
+/**
+ * Collection of constants for the connectivity module.
+ */
+public final class ConnectivityFlags {
+ /**
+ * Minimum module version at which to avoid rematching all requests when a network request is
+ * registered, and rematch only the registered requests instead.
+ */
+ @VisibleForTesting
+ public static final String NO_REMATCH_ALL_REQUESTS_ON_REGISTER =
+ "no_rematch_all_requests_on_register";
+
+ private boolean mNoRematchAllRequestsOnRegister;
+
+ /**
+ * Whether ConnectivityService should avoid avoid rematching all requests when a network
+ * request is registered, and rematch only the registered requests instead.
+ *
+ * This flag is disabled by default.
+ *
+ * IMPORTANT NOTE: This flag is false by default and will only be loaded in ConnectivityService
+ * systemReady. It is also not volatile for performance reasons, so for most threads it may
+ * only change to true after some time. This is fine for this particular flag because it only
+ * controls whether all requests or a subset of requests should be rematched, which is only
+ * a performance optimization, so its value does not need to be consistent over time; but most
+ * flags will not have these properties and should not use the same model.
+ *
+ * TODO: when adding other flags, consider the appropriate timing to load them, and necessary
+ * threading guarantees according to the semantics of the flags.
+ */
+ public boolean noRematchAllRequestsOnRegister() {
+ return mNoRematchAllRequestsOnRegister;
+ }
+
+ /**
+ * Load flag values. Should only be called once, and can only be called once PackageManager is
+ * ready.
+ */
+ public void loadFlags(ConnectivityService.Dependencies deps, Context ctx) {
+ mNoRematchAllRequestsOnRegister = deps.isFeatureEnabled(
+ ctx, NO_REMATCH_ALL_REQUESTS_ON_REGISTER, false /* defaultEnabled */);
+ }
+}
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index bc50d0d..e0dd886 100644
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -327,6 +327,7 @@
import com.android.server.ConnectivityService.ConnectivityDiagnosticsCallbackInfo;
import com.android.server.ConnectivityService.NetworkRequestInfo;
import com.android.server.ConnectivityServiceTest.ConnectivityServiceDependencies.ReportedInterfaces;
+import com.android.server.connectivity.ConnectivityFlags;
import com.android.server.connectivity.MockableSystemProperties;
import com.android.server.connectivity.Nat464Xlat;
import com.android.server.connectivity.NetworkAgentInfo;
@@ -1916,6 +1917,16 @@
mReportedInterfaceHistory.add(new ReportedInterfaces(context, iface, transportTypes));
super.reportNetworkInterfaceForTransports(context, iface, transportTypes);
}
+
+ @Override
+ public boolean isFeatureEnabled(Context context, String name, boolean defaultEnabled) {
+ switch (name) {
+ case ConnectivityFlags.NO_REMATCH_ALL_REQUESTS_ON_REGISTER:
+ return true;
+ default:
+ return super.isFeatureEnabled(context, name, defaultEnabled);
+ }
+ }
}
private static void initAlarmManager(final AlarmManager am, final Handler alarmHandler) {