Merge "Add forwarding methods to RoutingCoordinator" into main
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 2a25a86..8d67221 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -33,6 +33,7 @@
 
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
 import static com.android.net.module.util.NetworkStackConstants.RFC7421_PREFIX_LENGTH;
+import static com.android.networkstack.tethering.TetheringConfiguration.USE_SYNC_SM;
 import static com.android.networkstack.tethering.UpstreamNetworkState.isVcnInterface;
 import static com.android.networkstack.tethering.util.PrefixUtils.asIpPrefix;
 import static com.android.networkstack.tethering.util.TetheringMessageBase.BASE_IPSERVER;
@@ -56,7 +57,6 @@
 import android.net.dhcp.IDhcpServer;
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
 import android.os.Handler;
-import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
@@ -68,7 +68,6 @@
 
 import com.android.internal.util.MessageUtils;
 import com.android.internal.util.State;
-import com.android.internal.util.StateMachine;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.NetdUtils;
@@ -85,6 +84,8 @@
 import com.android.networkstack.tethering.metrics.TetheringMetrics;
 import com.android.networkstack.tethering.util.InterfaceSet;
 import com.android.networkstack.tethering.util.PrefixUtils;
+import com.android.networkstack.tethering.util.StateMachineShim;
+import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo;
 
 import java.net.Inet4Address;
 import java.net.Inet6Address;
@@ -104,7 +105,7 @@
  *
  * @hide
  */
-public class IpServer extends StateMachine {
+public class IpServer extends StateMachineShim {
     public static final int STATE_UNAVAILABLE = 0;
     public static final int STATE_AVAILABLE   = 1;
     public static final int STATE_TETHERED    = 2;
@@ -309,16 +310,18 @@
     private LinkAddress mIpv4Address;
 
     private final TetheringMetrics mTetheringMetrics;
+    private final Handler mHandler;
 
     // TODO: Add a dependency object to pass the data members or variables from the tethering
     // object. It helps to reduce the arguments of the constructor.
     public IpServer(
-            String ifaceName, Looper looper, int interfaceType, SharedLog log,
+            String ifaceName, Handler handler, int interfaceType, SharedLog log,
             INetd netd, @NonNull BpfCoordinator bpfCoordinator,
             @Nullable LateSdk<RoutingCoordinatorManager> routingCoordinator, Callback callback,
             TetheringConfiguration config, PrivateAddressCoordinator addressCoordinator,
             TetheringMetrics tetheringMetrics, Dependencies deps) {
-        super(ifaceName, looper);
+        super(ifaceName, USE_SYNC_SM ? null : handler.getLooper());
+        mHandler = handler;
         mLog = log.forSubComponent(ifaceName);
         mNetd = netd;
         mBpfCoordinator = bpfCoordinator;
@@ -351,13 +354,22 @@
         mTetheredState = new TetheredState();
         mUnavailableState = new UnavailableState();
         mWaitingForRestartState = new WaitingForRestartState();
-        addState(mInitialState);
-        addState(mLocalHotspotState);
-        addState(mTetheredState);
-        addState(mWaitingForRestartState, mTetheredState);
-        addState(mUnavailableState);
+        final ArrayList allStates = new ArrayList<StateInfo>();
+        allStates.add(new StateInfo(mInitialState, null));
+        allStates.add(new StateInfo(mLocalHotspotState, null));
+        allStates.add(new StateInfo(mTetheredState, null));
+        allStates.add(new StateInfo(mWaitingForRestartState, mTetheredState));
+        allStates.add(new StateInfo(mUnavailableState, null));
+        addAllStates(allStates);
+    }
 
-        setInitialState(mInitialState);
+    private Handler getHandler() {
+        return mHandler;
+    }
+
+    /** Start IpServer state machine. */
+    public void start() {
+        start(mInitialState);
     }
 
     /** Interface name which IpServer served.*/
diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index f52bed9..b7607ef 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -2841,7 +2841,7 @@
 
         mLog.i("adding IpServer for: " + iface);
         final TetherState tetherState = new TetherState(
-                new IpServer(iface, mLooper, interfaceType, mLog, mNetd, mBpfCoordinator,
+                new IpServer(iface, mHandler, interfaceType, mLog, mNetd, mBpfCoordinator,
                         mRoutingCoordinator, makeControlCallback(), mConfig,
                         mPrivateAddressCoordinator, mTetheringMetrics,
                         mDeps.getIpServerDependencies()), isNcm);
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 747cc20..502fee8 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -136,6 +136,9 @@
      */
     public static final int DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS = 5000;
 
+    /** A flag for using synchronous or asynchronous state machine. */
+    public static final boolean USE_SYNC_SM = false;
+
     public final String[] tetherableUsbRegexs;
     public final String[] tetherableWifiRegexs;
     public final String[] tetherableWigigRegexs;
diff --git a/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java b/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java
new file mode 100644
index 0000000..fc432f7
--- /dev/null
+++ b/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2023 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.networkstack.tethering.util;
+
+import android.annotation.Nullable;
+import android.os.Looper;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.State;
+import com.android.internal.util.StateMachine;
+import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo;
+
+import java.util.List;
+
+/** A wrapper to decide whether use synchronous state machine for tethering. */
+public class StateMachineShim {
+    // Exactly one of mAsyncSM or mSyncSM is non-null.
+    private final StateMachine mAsyncSM;
+    private final SyncStateMachine mSyncSM;
+
+    /**
+     * The Looper parameter is only needed for AsyncSM, so if looper is null, the shim will be
+     * created for SyncSM.
+     */
+    public StateMachineShim(final String name, @Nullable final Looper looper) {
+        this(name, looper, new Dependencies());
+    }
+
+    @VisibleForTesting
+    public StateMachineShim(final String name, @Nullable final Looper looper,
+            final Dependencies deps) {
+        if (looper == null) {
+            mAsyncSM = null;
+            mSyncSM = deps.makeSyncStateMachine(name, Thread.currentThread());
+        } else {
+            mAsyncSM = deps.makeAsyncStateMachine(name, looper);
+            mSyncSM = null;
+        }
+    }
+
+    /** A dependencies class which used for testing injection. */
+    @VisibleForTesting
+    public static class Dependencies {
+        /** Create SyncSM instance, for injection. */
+        public SyncStateMachine makeSyncStateMachine(final String name, final Thread thread) {
+            return new SyncStateMachine(name, thread);
+        }
+
+        /** Create AsyncSM instance, for injection. */
+        public AsyncStateMachine makeAsyncStateMachine(final String name, final Looper looper) {
+            return new AsyncStateMachine(name, looper);
+        }
+    }
+
+    /** Start the state machine */
+    public void start(final State initialState) {
+        if (mSyncSM != null) {
+            mSyncSM.start(initialState);
+        } else {
+            mAsyncSM.setInitialState(initialState);
+            mAsyncSM.start();
+        }
+    }
+
+    /** Add states to state machine. */
+    public void addAllStates(final List<StateInfo> stateInfos) {
+        if (mSyncSM != null) {
+            mSyncSM.addAllStates(stateInfos);
+        } else {
+            for (final StateInfo info : stateInfos) {
+                mAsyncSM.addState(info.state, info.parent);
+            }
+        }
+    }
+
+    /**
+     * Transition to given state.
+     *
+     * SyncSM doesn't allow this be called during state transition (#enter() or #exit() methods),
+     * or multiple times while processing a single message.
+     */
+    public void transitionTo(final State state) {
+        if (mSyncSM != null) {
+            mSyncSM.transitionTo(state);
+        } else {
+            mAsyncSM.transitionTo(state);
+        }
+    }
+
+    /** Send message to state machine. */
+    public void sendMessage(int what) {
+        sendMessage(what, 0, 0, null);
+    }
+
+    /** Send message to state machine. */
+    public void sendMessage(int what, Object obj) {
+        sendMessage(what, 0, 0, obj);
+    }
+
+    /** Send message to state machine. */
+    public void sendMessage(int what, int arg1) {
+        sendMessage(what, arg1, 0, null);
+    }
+
+    /**
+     * Send message to state machine.
+     *
+     * If using asynchronous state machine, putting the message into looper's message queue.
+     * Tethering runs on single looper thread that ipServers and mainSM all share with same message
+     * queue. The enqueued message will be processed by asynchronous state machine when all the
+     * messages before such enqueued message are processed.
+     * If using synchronous state machine, the message is processed right away without putting into
+     * looper's message queue.
+     */
+    public void sendMessage(int what, int arg1, int arg2, Object obj) {
+        if (mSyncSM != null) {
+            mSyncSM.processMessage(what, arg1, arg2, obj);
+        } else {
+            mAsyncSM.sendMessage(what, arg1, arg2, obj);
+        }
+    }
+
+    /**
+     * Send message after delayMillis millisecond.
+     *
+     * This can only be used with async state machine, so this will throw if using sync state
+     * machine.
+     */
+    public void sendMessageDelayedToAsyncSM(final int what, final long delayMillis) {
+        if (mSyncSM != null) {
+            throw new IllegalStateException("sendMessageDelayed can only be used with async SM");
+        }
+
+        mAsyncSM.sendMessageDelayed(what, delayMillis);
+    }
+
+    /**
+     * Send self message.
+     * This can only be used with sync state machine, so this will throw if using async state
+     * machine.
+     */
+    public void sendSelfMessageToSyncSM(final int what, final Object obj) {
+        if (mSyncSM == null) {
+            throw new IllegalStateException("sendSelfMessage can only be used with sync SM");
+        }
+
+        mSyncSM.sendSelfMessage(what, 0, 0, obj);
+    }
+
+    /**
+     * An alias StateMahchine class with public construtor.
+     *
+     * Since StateMachine.java only provides protected construtor, adding a child class so that this
+     * shim could create StateMachine instance.
+     */
+    @VisibleForTesting
+    public static class AsyncStateMachine extends StateMachine {
+        public AsyncStateMachine(final String name, final Looper looper) {
+            super(name, looper);
+        }
+    }
+}
diff --git a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
index 15df3ba..9724bd4 100644
--- a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
+++ b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
@@ -215,6 +215,7 @@
     @Captor private ArgumentCaptor<DhcpServingParamsParcel> mDhcpParamsCaptor;
 
     private final TestLooper mLooper = new TestLooper();
+    private final Handler mHandler = new Handler(mLooper.getLooper());
     private final ArgumentCaptor<LinkProperties> mLinkPropertiesCaptor =
             ArgumentCaptor.forClass(LinkProperties.class);
     private IpServer mIpServer;
@@ -254,7 +255,7 @@
         // Recreate mBpfCoordinator again here because mTetherConfig has changed
         mBpfCoordinator = spy(new BpfCoordinator(mBpfDeps));
         mIpServer = new IpServer(
-                IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog, mNetd, mBpfCoordinator,
+                IFACE_NAME, mHandler, interfaceType, mSharedLog, mNetd, mBpfCoordinator,
                 mRoutingCoordinatorManager, mCallback, mTetherConfig, mAddressCoordinator,
                 mTetheringMetrics, mDependencies);
         mIpServer.start();
@@ -341,7 +342,7 @@
         mBpfDeps = new BpfCoordinator.Dependencies() {
                     @NonNull
                     public Handler getHandler() {
-                        return new Handler(mLooper.getLooper());
+                        return mHandler;
                     }
 
                     @NonNull
@@ -419,7 +420,7 @@
     public void startsOutAvailable() {
         when(mDependencies.getIpNeighborMonitor(any(), any(), any()))
                 .thenReturn(mIpNeighborMonitor);
-        mIpServer = new IpServer(IFACE_NAME, mLooper.getLooper(), TETHERING_BLUETOOTH, mSharedLog,
+        mIpServer = new IpServer(IFACE_NAME, mHandler, TETHERING_BLUETOOTH, mSharedLog,
                 mNetd, mBpfCoordinator, mRoutingCoordinatorManager, mCallback, mTetherConfig,
                 mAddressCoordinator, mTetheringMetrics, mDependencies);
         mIpServer.start();
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt b/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt
new file mode 100644
index 0000000..2c4df76
--- /dev/null
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt
@@ -0,0 +1,128 @@
+/**
+ * Copyright (C) 2023 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.networkstack.tethering.util
+
+import android.os.Looper
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import com.android.internal.util.State
+import com.android.networkstack.tethering.util.StateMachineShim.AsyncStateMachine
+import com.android.networkstack.tethering.util.StateMachineShim.Dependencies
+import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo
+import kotlin.test.assertFailsWith
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.inOrder
+import org.mockito.Mockito.mock
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.verifyNoMoreInteractions
+
+@RunWith(AndroidJUnit4::class)
+@SmallTest
+class StateMachineShimTest {
+    private val mSyncSM = mock(SyncStateMachine::class.java)
+    private val mAsyncSM = mock(AsyncStateMachine::class.java)
+    private val mState1 = mock(State::class.java)
+    private val mState2 = mock(State::class.java)
+
+    inner class MyDependencies() : Dependencies() {
+
+        override fun makeSyncStateMachine(name: String, thread: Thread) = mSyncSM
+
+        override fun makeAsyncStateMachine(name: String, looper: Looper) = mAsyncSM
+    }
+
+    @Test
+    fun testUsingSyncStateMachine() {
+        val inOrder = inOrder(mSyncSM, mAsyncSM)
+        val shimUsingSyncSM = StateMachineShim("ShimTest", null, MyDependencies())
+        shimUsingSyncSM.start(mState1)
+        inOrder.verify(mSyncSM).start(mState1)
+
+        val allStates = ArrayList<StateInfo>()
+        allStates.add(StateInfo(mState1, null))
+        allStates.add(StateInfo(mState2, mState1))
+        shimUsingSyncSM.addAllStates(allStates)
+        inOrder.verify(mSyncSM).addAllStates(allStates)
+
+        shimUsingSyncSM.transitionTo(mState1)
+        inOrder.verify(mSyncSM).transitionTo(mState1)
+
+        val what = 10
+        shimUsingSyncSM.sendMessage(what)
+        inOrder.verify(mSyncSM).processMessage(what, 0, 0, null)
+        val obj = Object()
+        shimUsingSyncSM.sendMessage(what, obj)
+        inOrder.verify(mSyncSM).processMessage(what, 0, 0, obj)
+        val arg1 = 11
+        shimUsingSyncSM.sendMessage(what, arg1)
+        inOrder.verify(mSyncSM).processMessage(what, arg1, 0, null)
+        val arg2 = 12
+        shimUsingSyncSM.sendMessage(what, arg1, arg2, obj)
+        inOrder.verify(mSyncSM).processMessage(what, arg1, arg2, obj)
+
+        assertFailsWith(IllegalStateException::class) {
+            shimUsingSyncSM.sendMessageDelayedToAsyncSM(what, 1000 /* delayMillis */)
+        }
+
+        shimUsingSyncSM.sendSelfMessageToSyncSM(what, obj)
+        inOrder.verify(mSyncSM).sendSelfMessage(what, 0, 0, obj)
+
+        verifyNoMoreInteractions(mSyncSM, mAsyncSM)
+    }
+
+    @Test
+    fun testUsingAsyncStateMachine() {
+        val inOrder = inOrder(mSyncSM, mAsyncSM)
+        val shimUsingAsyncSM = StateMachineShim("ShimTest", mock(Looper::class.java),
+                MyDependencies())
+        shimUsingAsyncSM.start(mState1)
+        inOrder.verify(mAsyncSM).setInitialState(mState1)
+        inOrder.verify(mAsyncSM).start()
+
+        val allStates = ArrayList<StateInfo>()
+        allStates.add(StateInfo(mState1, null))
+        allStates.add(StateInfo(mState2, mState1))
+        shimUsingAsyncSM.addAllStates(allStates)
+        inOrder.verify(mAsyncSM).addState(mState1, null)
+        inOrder.verify(mAsyncSM).addState(mState2, mState1)
+
+        shimUsingAsyncSM.transitionTo(mState1)
+        inOrder.verify(mAsyncSM).transitionTo(mState1)
+
+        val what = 10
+        shimUsingAsyncSM.sendMessage(what)
+        inOrder.verify(mAsyncSM).sendMessage(what, 0, 0, null)
+        val obj = Object()
+        shimUsingAsyncSM.sendMessage(what, obj)
+        inOrder.verify(mAsyncSM).sendMessage(what, 0, 0, obj)
+        val arg1 = 11
+        shimUsingAsyncSM.sendMessage(what, arg1)
+        inOrder.verify(mAsyncSM).sendMessage(what, arg1, 0, null)
+        val arg2 = 12
+        shimUsingAsyncSM.sendMessage(what, arg1, arg2, obj)
+        inOrder.verify(mAsyncSM).sendMessage(what, arg1, arg2, obj)
+
+        shimUsingAsyncSM.sendMessageDelayedToAsyncSM(what, 1000 /* delayMillis */)
+        inOrder.verify(mAsyncSM).sendMessageDelayed(what, 1000)
+
+        assertFailsWith(IllegalStateException::class) {
+            shimUsingAsyncSM.sendSelfMessageToSyncSM(what, obj)
+        }
+
+        verifyNoMoreInteractions(mSyncSM, mAsyncSM)
+    }
+}
diff --git a/framework-t/api/system-current.txt b/framework-t/api/system-current.txt
index 6c98a4f..23510e1 100644
--- a/framework-t/api/system-current.txt
+++ b/framework-t/api/system-current.txt
@@ -492,12 +492,12 @@
     field @NonNull public static final android.os.Parcelable.Creator<android.net.thread.PendingOperationalDataset> CREATOR;
   }
 
-  @FlaggedApi("com.android.net.thread.flags.thread_enabled") public class ThreadNetworkController {
+  @FlaggedApi("com.android.net.thread.flags.thread_enabled") public final class ThreadNetworkController {
     method public int getThreadVersion();
     field public static final int THREAD_VERSION_1_3 = 4; // 0x4
   }
 
-  @FlaggedApi("com.android.net.thread.flags.thread_enabled") public class ThreadNetworkManager {
+  @FlaggedApi("com.android.net.thread.flags.thread_enabled") public final class ThreadNetworkManager {
     method @NonNull public java.util.List<android.net.thread.ThreadNetworkController> getAllThreadNetworkControllers();
   }
 
diff --git a/netbpfload/NetBpfLoad.cpp b/netbpfload/NetBpfLoad.cpp
index d150373..6152287 100644
--- a/netbpfload/NetBpfLoad.cpp
+++ b/netbpfload/NetBpfLoad.cpp
@@ -38,6 +38,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
+#include <android/api-level.h>
 #include <android-base/logging.h>
 #include <android-base/macros.h>
 #include <android-base/properties.h>
@@ -172,6 +173,9 @@
     (void)argc;
     android::base::InitLogging(argv, &android::base::KernelLogger);
 
+    const int device_api_level = android_get_device_api_level();
+    const bool isAtLeastU = (device_api_level >= __ANDROID_API_U__);
+
     if (!android::bpf::isAtLeastKernelVersion(4, 19, 0)) {
         ALOGE("Android U QPR2 requires kernel 4.19.");
         return 1;
@@ -208,24 +212,27 @@
         return 1;
     }
 
-    // Linux 5.16-rc1 changed the default to 2 (disabled but changeable), but we need 0 (enabled)
-    // (this writeFile is known to fail on at least 4.19, but always defaults to 0 on pre-5.13,
-    // on 5.13+ it depends on CONFIG_BPF_UNPRIV_DEFAULT_OFF)
-    if (writeProcSysFile("/proc/sys/kernel/unprivileged_bpf_disabled", "0\n") &&
-        android::bpf::isAtLeastKernelVersion(5, 13, 0)) return 1;
+    if (isAtLeastU) {
+        // Linux 5.16-rc1 changed the default to 2 (disabled but changeable),
+        // but we need 0 (enabled)
+        // (this writeFile is known to fail on at least 4.19, but always defaults to 0 on
+        // pre-5.13, on 5.13+ it depends on CONFIG_BPF_UNPRIV_DEFAULT_OFF)
+        if (writeProcSysFile("/proc/sys/kernel/unprivileged_bpf_disabled", "0\n") &&
+            android::bpf::isAtLeastKernelVersion(5, 13, 0)) return 1;
 
-    // Enable the eBPF JIT -- but do note that on 64-bit kernels it is likely
-    // already force enabled by the kernel config option BPF_JIT_ALWAYS_ON.
-    // (Note: this (open) will fail with ENOENT 'No such file or directory' if
-    //  kernel does not have CONFIG_BPF_JIT=y)
-    // BPF_JIT is required by R VINTF (which means 4.14/4.19/5.4 kernels),
-    // but 4.14/4.19 were released with P & Q, and only 5.4 is new in R+.
-    if (writeProcSysFile("/proc/sys/net/core/bpf_jit_enable", "1\n")) return 1;
+        // Enable the eBPF JIT -- but do note that on 64-bit kernels it is likely
+        // already force enabled by the kernel config option BPF_JIT_ALWAYS_ON.
+        // (Note: this (open) will fail with ENOENT 'No such file or directory' if
+        //  kernel does not have CONFIG_BPF_JIT=y)
+        // BPF_JIT is required by R VINTF (which means 4.14/4.19/5.4 kernels),
+        // but 4.14/4.19 were released with P & Q, and only 5.4 is new in R+.
+        if (writeProcSysFile("/proc/sys/net/core/bpf_jit_enable", "1\n")) return 1;
 
-    // Enable JIT kallsyms export for privileged users only
-    // (Note: this (open) will fail with ENOENT 'No such file or directory' if
-    //  kernel does not have CONFIG_HAVE_EBPF_JIT=y)
-    if (writeProcSysFile("/proc/sys/net/core/bpf_jit_kallsyms", "1\n")) return 1;
+        // Enable JIT kallsyms export for privileged users only
+        // (Note: this (open) will fail with ENOENT 'No such file or directory' if
+        //  kernel does not have CONFIG_HAVE_EBPF_JIT=y)
+        if (writeProcSysFile("/proc/sys/net/core/bpf_jit_kallsyms", "1\n")) return 1;
+    }
 
     // Create all the pin subdirectories
     // (this must be done first to allow selinux_context and pin_subdir functionality,
diff --git a/service-t/src/com/android/server/net/NetworkStatsEventLogger.java b/service-t/src/com/android/server/net/NetworkStatsEventLogger.java
new file mode 100644
index 0000000..679837a
--- /dev/null
+++ b/service-t/src/com/android/server/net/NetworkStatsEventLogger.java
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2023 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.net;
+
+import static com.android.internal.annotations.VisibleForTesting.Visibility.PRIVATE;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.util.IndentingPrintWriter;
+import android.util.LocalLog;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Helper class for NetworkStatsService to log events.
+ *
+ * @hide
+ */
+public class NetworkStatsEventLogger {
+    static final int POLL_REASON_DUMPSYS = 0;
+    static final int POLL_REASON_FORCE_UPDATE = 1;
+    static final int POLL_REASON_GLOBAL_ALERT = 2;
+    static final int POLL_REASON_NETWORK_STATUS_CHANGED = 3;
+    static final int POLL_REASON_OPEN_SESSION = 4;
+    static final int POLL_REASON_PERIODIC = 5;
+    static final int POLL_REASON_RAT_CHANGED = 6;
+    static final int POLL_REASON_REG_CALLBACK = 7;
+    static final int POLL_REASON_REMOVE_UIDS = 8;
+    static final int POLL_REASON_UPSTREAM_CHANGED = 9;
+
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = { "POLL_REASON_" }, value = {
+            POLL_REASON_DUMPSYS,
+            POLL_REASON_FORCE_UPDATE,
+            POLL_REASON_GLOBAL_ALERT,
+            POLL_REASON_NETWORK_STATUS_CHANGED,
+            POLL_REASON_OPEN_SESSION,
+            POLL_REASON_PERIODIC,
+            POLL_REASON_RAT_CHANGED,
+            POLL_REASON_REMOVE_UIDS,
+            POLL_REASON_REG_CALLBACK,
+            POLL_REASON_UPSTREAM_CHANGED
+    })
+    public @interface PollReason {
+    }
+    static final int MAX_POLL_REASON = POLL_REASON_UPSTREAM_CHANGED;
+
+    @VisibleForTesting(visibility = PRIVATE)
+    public static final int MAX_EVENTS_LOGS = 50;
+    private final LocalLog mEventChanges = new LocalLog(MAX_EVENTS_LOGS);
+    private final int[] mPollEventCounts = new int[MAX_POLL_REASON + 1];
+
+    /**
+     * Log a poll event.
+     *
+     * @param flags Flags used when polling. See NetworkStatsService#FLAG_PERSIST_*.
+     * @param event The event of polling to be logged.
+     */
+    public void logPollEvent(int flags, @NonNull PollEvent event) {
+        mEventChanges.log("Poll(flags=" + flags + ", " + event + ")");
+        mPollEventCounts[event.reason]++;
+    }
+
+    /**
+     * Print poll counts per reason into the given stream.
+     */
+    @VisibleForTesting(visibility = PRIVATE)
+    public void dumpPollCountsPerReason(@NonNull IndentingPrintWriter pw) {
+        pw.println("Poll counts per reason:");
+        pw.increaseIndent();
+        for (int i = 0; i <= MAX_POLL_REASON; i++) {
+            pw.println(PollEvent.pollReasonNameOf(i) + ": " + mPollEventCounts[i]);
+        }
+        pw.decreaseIndent();
+        pw.println();
+    }
+
+    /**
+     * Print recent poll events into the given stream.
+     */
+    @VisibleForTesting(visibility = PRIVATE)
+    public void dumpRecentPollEvents(@NonNull IndentingPrintWriter pw) {
+        pw.println("Recent poll events:");
+        pw.increaseIndent();
+        mEventChanges.reverseDump(pw);
+        pw.decreaseIndent();
+        pw.println();
+    }
+
+    /**
+     * Print the object's state into the given stream.
+     */
+    public void dump(@NonNull IndentingPrintWriter pw) {
+        dumpPollCountsPerReason(pw);
+        dumpRecentPollEvents(pw);
+    }
+
+    public static class PollEvent {
+        public final int reason;
+
+        public PollEvent(@PollReason int reason) {
+            if (reason < 0 || reason > MAX_POLL_REASON) {
+                throw new IllegalArgumentException("Unsupported poll reason: " + reason);
+            }
+            this.reason = reason;
+        }
+
+        @Override
+        public String toString() {
+            return "PollEvent{" + "reason=" + pollReasonNameOf(reason) + "}";
+        }
+
+        /**
+         * Get the name of the given reason.
+         *
+         * If the reason does not have a String representation, returns its integer representation.
+         */
+        @NonNull
+        public static String pollReasonNameOf(@PollReason int reason) {
+            switch (reason) {
+                case POLL_REASON_DUMPSYS:                   return "DUMPSYS";
+                case POLL_REASON_FORCE_UPDATE:              return "FORCE_UPDATE";
+                case POLL_REASON_GLOBAL_ALERT:              return "GLOBAL_ALERT";
+                case POLL_REASON_NETWORK_STATUS_CHANGED:    return "NETWORK_STATUS_CHANGED";
+                case POLL_REASON_OPEN_SESSION:              return "OPEN_SESSION";
+                case POLL_REASON_PERIODIC:                  return "PERIODIC";
+                case POLL_REASON_RAT_CHANGED:               return "RAT_CHANGED";
+                case POLL_REASON_REMOVE_UIDS:               return "REMOVE_UIDS";
+                case POLL_REASON_REG_CALLBACK:              return "REG_CALLBACK";
+                case POLL_REASON_UPSTREAM_CHANGED:          return "UPSTREAM_CHANGED";
+                default:                                    return Integer.toString(reason);
+            }
+        }
+    }
+}
diff --git a/service-t/src/com/android/server/net/NetworkStatsService.java b/service-t/src/com/android/server/net/NetworkStatsService.java
index cc67550..46afd31 100644
--- a/service-t/src/com/android/server/net/NetworkStatsService.java
+++ b/service-t/src/com/android/server/net/NetworkStatsService.java
@@ -66,6 +66,17 @@
 import static com.android.internal.annotations.VisibleForTesting.Visibility.PRIVATE;
 import static com.android.net.module.util.NetworkCapabilitiesUtils.getDisplayTransport;
 import static com.android.net.module.util.NetworkStatsUtils.LIMIT_GLOBAL_ALERT;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_PERIODIC;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_DUMPSYS;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_FORCE_UPDATE;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_GLOBAL_ALERT;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_NETWORK_STATUS_CHANGED;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_OPEN_SESSION;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_RAT_CHANGED;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_REG_CALLBACK;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_REMOVE_UIDS;
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_UPSTREAM_CHANGED;
+import static com.android.server.net.NetworkStatsEventLogger.PollEvent;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -281,6 +292,8 @@
     static final String NETSTATS_IMPORT_ATTEMPTS_COUNTER_NAME = "import.attempts";
     static final String NETSTATS_IMPORT_SUCCESSES_COUNTER_NAME = "import.successes";
     static final String NETSTATS_IMPORT_FALLBACKS_COUNTER_NAME = "import.fallbacks";
+    static final String CONFIG_ENABLE_NETWORK_STATS_EVENT_LOGGER =
+            "enable_network_stats_event_logger";
 
     private final Context mContext;
     private final NetworkStatsFactory mStatsFactory;
@@ -441,6 +454,7 @@
      * Map from key {@code OpenSessionKey} to count of opened sessions. This is for recording
      * the caller of open session and it is only for debugging.
      */
+    // TODO: Move to NetworkStatsEventLogger to centralize event logging.
     @GuardedBy("mOpenSessionCallsLock")
     private final HashMap<OpenSessionKey, Integer> mOpenSessionCallsPerCaller = new HashMap<>();
 
@@ -513,20 +527,21 @@
         public void handleMessage(Message msg) {
             switch (msg.what) {
                 case MSG_PERFORM_POLL: {
-                    performPoll(FLAG_PERSIST_ALL);
+                    performPoll(FLAG_PERSIST_ALL, maybeCreatePollEvent((int) msg.obj));
                     break;
                 }
                 case MSG_NOTIFY_NETWORK_STATUS: {
                     synchronized (mStatsLock) {
                         // If no cached states, ignore.
                         if (mLastNetworkStateSnapshots == null) break;
-                        handleNotifyNetworkStatus(
-                                mDefaultNetworks, mLastNetworkStateSnapshots, mActiveIface);
+                        handleNotifyNetworkStatus(mDefaultNetworks, mLastNetworkStateSnapshots,
+                                mActiveIface, maybeCreatePollEvent((int) msg.obj));
                     }
                     break;
                 }
                 case MSG_PERFORM_POLL_REGISTER_ALERT: {
-                    performPoll(FLAG_PERSIST_NETWORK);
+                    performPoll(FLAG_PERSIST_NETWORK,
+                            maybeCreatePollEvent(POLL_REASON_GLOBAL_ALERT));
                     registerGlobalAlert();
                     break;
                 }
@@ -612,6 +627,13 @@
         mStatsMapB = mDeps.getStatsMapB();
         mAppUidStatsMap = mDeps.getAppUidStatsMap();
         mIfaceStatsMap = mDeps.getIfaceStatsMap();
+        // To prevent any possible races, the flag is not allowed to change until rebooting.
+        mSupportEventLogger = mDeps.supportEventLogger(mContext);
+        if (mSupportEventLogger) {
+            mEventLogger = new NetworkStatsEventLogger();
+        } else {
+            mEventLogger = null;
+        }
 
         // TODO: Remove bpfNetMaps creation and always start SkDestroyListener
         // Following code is for the experiment to verify the SkDestroyListener refactoring. Based
@@ -840,6 +862,14 @@
                 IBpfMap<CookieTagMapKey, CookieTagMapValue> cookieTagMap, Handler handler) {
             return new SkDestroyListener(cookieTagMap, handler, new SharedLog(TAG));
         }
+
+        /**
+         * Get whether event logger feature is supported.
+         */
+        public boolean supportEventLogger(Context ctx) {
+            return DeviceConfigUtils.isTetheringFeatureNotChickenedOut(
+                    ctx, CONFIG_ENABLE_NETWORK_STATS_EVENT_LOGGER);
+        }
     }
 
     /**
@@ -1432,7 +1462,7 @@
                 | NetworkStatsManager.FLAG_POLL_FORCE)) != 0) {
             final long ident = Binder.clearCallingIdentity();
             try {
-                performPoll(FLAG_PERSIST_ALL);
+                performPoll(FLAG_PERSIST_ALL, maybeCreatePollEvent(POLL_REASON_OPEN_SESSION));
             } finally {
                 Binder.restoreCallingIdentity(ident);
             }
@@ -1828,7 +1858,8 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            handleNotifyNetworkStatus(defaultNetworks, networkStates, activeIface);
+            handleNotifyNetworkStatus(defaultNetworks, networkStates, activeIface,
+                    maybeCreatePollEvent(POLL_REASON_NETWORK_STATUS_CHANGED));
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -1845,7 +1876,8 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            performPoll(FLAG_PERSIST_ALL);
+            // TODO: Log callstack for system server callers.
+            performPoll(FLAG_PERSIST_ALL, maybeCreatePollEvent(POLL_REASON_FORCE_UPDATE));
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -1902,7 +1934,8 @@
         }
 
         // Create baseline stats
-        mHandler.sendMessage(mHandler.obtainMessage(MSG_PERFORM_POLL));
+        mHandler.sendMessage(mHandler.obtainMessage(MSG_PERFORM_POLL,
+                POLL_REASON_REG_CALLBACK));
 
         return normalizedRequest;
    }
@@ -1999,7 +2032,8 @@
             new TetheringManager.TetheringEventCallback() {
                 @Override
                 public void onUpstreamChanged(@Nullable Network network) {
-                    performPoll(FLAG_PERSIST_NETWORK);
+                    performPoll(FLAG_PERSIST_NETWORK,
+                            maybeCreatePollEvent(POLL_REASON_UPSTREAM_CHANGED));
                 }
             };
 
@@ -2008,7 +2042,7 @@
         public void onReceive(Context context, Intent intent) {
             // on background handler thread, and verified UPDATE_DEVICE_STATS
             // permission above.
-            performPoll(FLAG_PERSIST_ALL);
+            performPoll(FLAG_PERSIST_ALL, maybeCreatePollEvent(POLL_REASON_PERIODIC));
 
             // verify that we're watching global alert
             registerGlobalAlert();
@@ -2072,19 +2106,20 @@
     public void handleOnCollapsedRatTypeChanged() {
         // Protect service from frequently updating. Remove pending messages if any.
         mHandler.removeMessages(MSG_NOTIFY_NETWORK_STATUS);
-        mHandler.sendMessageDelayed(
-                mHandler.obtainMessage(MSG_NOTIFY_NETWORK_STATUS), mSettings.getPollDelay());
+        mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_NOTIFY_NETWORK_STATUS,
+                        POLL_REASON_RAT_CHANGED), mSettings.getPollDelay());
     }
 
     private void handleNotifyNetworkStatus(
             Network[] defaultNetworks,
             NetworkStateSnapshot[] snapshots,
-            String activeIface) {
+            String activeIface,
+            @Nullable PollEvent event) {
         synchronized (mStatsLock) {
             mWakeLock.acquire();
             try {
                 mActiveIface = activeIface;
-                handleNotifyNetworkStatusLocked(defaultNetworks, snapshots);
+                handleNotifyNetworkStatusLocked(defaultNetworks, snapshots, event);
             } finally {
                 mWakeLock.release();
             }
@@ -2098,7 +2133,7 @@
      */
     @GuardedBy("mStatsLock")
     private void handleNotifyNetworkStatusLocked(@NonNull Network[] defaultNetworks,
-            @NonNull NetworkStateSnapshot[] snapshots) {
+            @NonNull NetworkStateSnapshot[] snapshots, @Nullable PollEvent event) {
         if (!mSystemReady) return;
         if (LOGV) Log.v(TAG, "handleNotifyNetworkStatusLocked()");
 
@@ -2108,7 +2143,7 @@
 
         // poll, but only persist network stats to keep codepath fast. UID stats
         // will be persisted during next alarm poll event.
-        performPollLocked(FLAG_PERSIST_NETWORK);
+        performPollLocked(FLAG_PERSIST_NETWORK, event);
 
         // Rebuild active interfaces based on connected networks
         mActiveIfaces.clear();
@@ -2325,12 +2360,12 @@
         }
     }
 
-    private void performPoll(int flags) {
+    private void performPoll(int flags, @Nullable PollEvent event) {
         synchronized (mStatsLock) {
             mWakeLock.acquire();
 
             try {
-                performPollLocked(flags);
+                performPollLocked(flags, event);
             } finally {
                 mWakeLock.release();
             }
@@ -2342,11 +2377,15 @@
      * {@link NetworkStatsHistory}.
      */
     @GuardedBy("mStatsLock")
-    private void performPollLocked(int flags) {
+    private void performPollLocked(int flags, @Nullable PollEvent event) {
         if (!mSystemReady) return;
         if (LOGV) Log.v(TAG, "performPollLocked(flags=0x" + Integer.toHexString(flags) + ")");
         Trace.traceBegin(TRACE_TAG_NETWORK, "performPollLocked");
 
+        if (mSupportEventLogger) {
+            mEventLogger.logPollEvent(flags, event);
+        }
+
         final boolean persistNetwork = (flags & FLAG_PERSIST_NETWORK) != 0;
         final boolean persistUid = (flags & FLAG_PERSIST_UID) != 0;
         final boolean persistForce = (flags & FLAG_PERSIST_FORCE) != 0;
@@ -2546,7 +2585,7 @@
         if (LOGV) Log.v(TAG, "removeUidsLocked() for UIDs " + Arrays.toString(uids));
 
         // Perform one last poll before removing
-        performPollLocked(FLAG_PERSIST_ALL);
+        performPollLocked(FLAG_PERSIST_ALL, maybeCreatePollEvent(POLL_REASON_REMOVE_UIDS));
 
         mUidRecorder.removeUidsLocked(uids);
         mUidTagRecorder.removeUidsLocked(uids);
@@ -2629,7 +2668,8 @@
             }
 
             if (poll) {
-                performPollLocked(FLAG_PERSIST_ALL | FLAG_PERSIST_FORCE);
+                performPollLocked(FLAG_PERSIST_ALL | FLAG_PERSIST_FORCE,
+                        maybeCreatePollEvent(POLL_REASON_DUMPSYS));
                 pw.println("Forced poll");
                 return;
             }
@@ -2689,6 +2729,7 @@
                     pw.println("(failed to dump platform legacy stats import counters)");
                 }
             }
+            pw.println(CONFIG_ENABLE_NETWORK_STATS_EVENT_LOGGER + ": " + mSupportEventLogger);
 
             pw.decreaseIndent();
 
@@ -2746,6 +2787,10 @@
             pw.decreaseIndent();
             pw.println();
 
+            if (mSupportEventLogger) {
+                mEventLogger.dump(pw);
+            }
+
             pw.println("Stats Providers:");
             pw.increaseIndent();
             invokeForAllStatsProviderCallbacks((cb) -> {
@@ -3215,6 +3260,22 @@
         }
     }
 
+    private final boolean mSupportEventLogger;
+    @GuardedBy("mStatsLock")
+    @Nullable
+    private final NetworkStatsEventLogger mEventLogger;
+
+    /**
+     * Create a PollEvent instance if the feature is enabled.
+     */
+    @Nullable
+    public PollEvent maybeCreatePollEvent(@NetworkStatsEventLogger.PollReason int reason) {
+        if (mSupportEventLogger) {
+            return new PollEvent(reason);
+        }
+        return null;
+    }
+
     private class DropBoxNonMonotonicObserver implements NonMonotonicObserver<String> {
         @Override
         public void foundNonMonotonic(NetworkStats left, int leftIndex, NetworkStats right,
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index c559fa3..c4cb4c7 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -1538,9 +1538,9 @@
         /**
          * Get BPF program Id from CGROUP. See {@link BpfUtils#getProgramId}.
          */
-        public int getBpfProgramId(final int attachType, @NonNull final String cgroupPath)
+        public int getBpfProgramId(final int attachType)
                 throws IOException {
-            return BpfUtils.getProgramId(attachType, cgroupPath);
+            return BpfUtils.getProgramId(attachType);
         }
 
         /**
@@ -3274,15 +3274,15 @@
         pw.increaseIndent();
         try {
             pw.print("CGROUP_INET_INGRESS: ");
-            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET_INGRESS, BpfUtils.CGROUP_PATH));
+            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET_INGRESS));
             pw.print("CGROUP_INET_EGRESS: ");
-            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET_EGRESS, BpfUtils.CGROUP_PATH));
+            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET_EGRESS));
             pw.print("CGROUP_INET_SOCK_CREATE: ");
-            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET_SOCK_CREATE, BpfUtils.CGROUP_PATH));
+            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET_SOCK_CREATE));
             pw.print("CGROUP_INET4_BIND: ");
-            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET4_BIND, BpfUtils.CGROUP_PATH));
+            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET4_BIND));
             pw.print("CGROUP_INET6_BIND: ");
-            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET6_BIND, BpfUtils.CGROUP_PATH));
+            pw.println(mDeps.getBpfProgramId(BPF_CGROUP_INET6_BIND));
         } catch (IOException e) {
             pw.println("  IOException");
         }
@@ -10816,7 +10816,7 @@
                         // If type can't be parsed, this throws NumberFormatException, which
                         // is passed back to adb who prints it.
                         final int type = Integer.parseInt(getNextArg());
-                        final int ret = BpfUtils.getProgramId(type, BpfUtils.CGROUP_PATH);
+                        final int ret = BpfUtils.getProgramId(type);
                         pw.println(ret);
                         return 0;
                     }
diff --git a/staticlibs/device/com/android/net/module/util/BpfMap.java b/staticlibs/device/com/android/net/module/util/BpfMap.java
index d45cace..595ac74 100644
--- a/staticlibs/device/com/android/net/module/util/BpfMap.java
+++ b/staticlibs/device/com/android/net/module/util/BpfMap.java
@@ -187,12 +187,6 @@
         return nativeDeleteMapEntry(mMapFd.getFd(), key.writeToBytes());
     }
 
-    /** Returns {@code true} if this map contains no elements. */
-    @Override
-    public boolean isEmpty() throws ErrnoException {
-        return getFirstKey() == null;
-    }
-
     private K getNextKeyInternal(@Nullable K key) throws ErrnoException {
         byte[] rawKey = new byte[mKeySize];
 
@@ -245,49 +239,6 @@
         return Struct.parse(mValueClass, buffer);
     }
 
-    /**
-     * Iterate through the map and handle each key -> value retrieved base on the given BiConsumer.
-     * The given BiConsumer may to delete the passed-in entry, but is not allowed to perform any
-     * other structural modifications to the map, such as adding entries or deleting other entries.
-     * Otherwise, iteration will result in undefined behaviour.
-     */
-    @Override
-    public void forEach(ThrowingBiConsumer<K, V> action) throws ErrnoException {
-        @Nullable K nextKey = getFirstKey();
-
-        while (nextKey != null) {
-            @NonNull final K curKey = nextKey;
-            @NonNull final V value = getValue(curKey);
-
-            nextKey = getNextKey(curKey);
-            action.accept(curKey, value);
-        }
-    }
-
-    /* Empty implementation to implement AutoCloseable, so we can use BpfMaps
-     * with try with resources, but due to persistent FD cache, there is no actual
-     * need to close anything.  File descriptors will actually be closed when we
-     * unlock the BpfMap class and destroy the ParcelFileDescriptor objects.
-     */
-    @Override
-    public void close() throws IOException {
-    }
-
-    /**
-     * Clears the map. The map may already be empty.
-     *
-     * @throws ErrnoException if the map is already closed, if an error occurred during iteration,
-     *                        or if a non-ENOENT error occurred when deleting a key.
-     */
-    @Override
-    public void clear() throws ErrnoException {
-        K key = getFirstKey();
-        while (key != null) {
-            deleteEntry(key);  // ignores ENOENT.
-            key = getFirstKey();
-        }
-    }
-
     private static native int nativeBpfFdGet(String path, int mode, int keySize, int valueSize)
             throws ErrnoException, NullPointerException;
 
diff --git a/staticlibs/device/com/android/net/module/util/BpfUtils.java b/staticlibs/device/com/android/net/module/util/BpfUtils.java
index 6116a5f..10a8f60 100644
--- a/staticlibs/device/com/android/net/module/util/BpfUtils.java
+++ b/staticlibs/device/com/android/net/module/util/BpfUtils.java
@@ -41,49 +41,18 @@
     public static final String CGROUP_PATH = "/sys/fs/cgroup/";
 
     /**
-     * Attach BPF program to CGROUP
-     */
-    public static void attachProgram(int type, @NonNull String programPath,
-            @NonNull String cgroupPath, int flags) throws IOException {
-        native_attachProgramToCgroup(type, programPath, cgroupPath, flags);
-    }
-
-    /**
-     * Detach BPF program from CGROUP
-     */
-    public static void detachProgram(int type, @NonNull String cgroupPath)
-            throws IOException {
-        native_detachProgramFromCgroup(type, cgroupPath);
-    }
-
-    /**
      * Get BPF program Id from CGROUP.
      *
      * Note: This requires a 4.19 kernel which is only guaranteed on V+.
      *
      * @param attachType Bpf attach type. See bpf_attach_type in include/uapi/linux/bpf.h.
-     * @param cgroupPath Path of cgroup.
      * @return Positive integer for a Program Id. 0 if no program is attached.
      * @throws IOException if failed to open the cgroup directory or query bpf program.
      */
-    public static int getProgramId(int attachType, @NonNull String cgroupPath) throws IOException {
-        return native_getProgramIdFromCgroup(attachType, cgroupPath);
+    public static int getProgramId(int attachType) throws IOException {
+        return native_getProgramIdFromCgroup(attachType, CGROUP_PATH);
     }
 
-    /**
-     * Detach single BPF program from CGROUP
-     */
-    public static void detachSingleProgram(int type, @NonNull String programPath,
-            @NonNull String cgroupPath) throws IOException {
-        native_detachSingleProgramFromCgroup(type, programPath, cgroupPath);
-    }
-
-    private static native boolean native_attachProgramToCgroup(int type, String programPath,
-            String cgroupPath, int flags) throws IOException;
-    private static native boolean native_detachProgramFromCgroup(int type, String cgroupPath)
-            throws IOException;
-    private static native boolean native_detachSingleProgramFromCgroup(int type,
-            String programPath, String cgroupPath) throws IOException;
     private static native int native_getProgramIdFromCgroup(int type, String cgroupPath)
             throws IOException;
 }
diff --git a/staticlibs/device/com/android/net/module/util/IBpfMap.java b/staticlibs/device/com/android/net/module/util/IBpfMap.java
index 83ff875..ca56830 100644
--- a/staticlibs/device/com/android/net/module/util/IBpfMap.java
+++ b/staticlibs/device/com/android/net/module/util/IBpfMap.java
@@ -18,6 +18,7 @@
 import android.system.ErrnoException;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import java.io.IOException;
 import java.util.NoSuchElementException;
@@ -49,15 +50,17 @@
     /** Remove existing key from eBpf map. Return true if something was deleted. */
     boolean deleteEntry(K key) throws ErrnoException;
 
-    /** Returns {@code true} if this map contains no elements. */
-    boolean isEmpty() throws ErrnoException;
-
     /** Get the key after the passed-in key. */
     K getNextKey(@NonNull K key) throws ErrnoException;
 
     /** Get the first key of the eBpf map. */
     K getFirstKey() throws ErrnoException;
 
+    /** Returns {@code true} if this map contains no elements. */
+    default boolean isEmpty() throws ErrnoException {
+        return getFirstKey() == null;
+    }
+
     /** Check whether a key exists in the map. */
     boolean containsKey(@NonNull K key) throws ErrnoException;
 
@@ -70,13 +73,38 @@
 
     /**
      * Iterate through the map and handle each key -> value retrieved base on the given BiConsumer.
+     * The given BiConsumer may to delete the passed-in entry, but is not allowed to perform any
+     * other structural modifications to the map, such as adding entries or deleting other entries.
+     * Otherwise, iteration will result in undefined behaviour.
      */
-    void forEach(ThrowingBiConsumer<K, V> action) throws ErrnoException;
+    default public void forEach(ThrowingBiConsumer<K, V> action) throws ErrnoException {
+        @Nullable K nextKey = getFirstKey();
 
-    /** Clears the map. */
-    void clear() throws ErrnoException;
+        while (nextKey != null) {
+            @NonNull final K curKey = nextKey;
+            @NonNull final V value = getValue(curKey);
+
+            nextKey = getNextKey(curKey);
+            action.accept(curKey, value);
+        }
+    }
+
+    /**
+     * Clears the map. The map may already be empty.
+     *
+     * @throws ErrnoException if the map is already closed, if an error occurred during iteration,
+     *                        or if a non-ENOENT error occurred when deleting a key.
+     */
+    default public void clear() throws ErrnoException {
+        K key = getFirstKey();
+        while (key != null) {
+            deleteEntry(key);  // ignores ENOENT.
+            key = getFirstKey();
+        }
+    }
 
     /** Close for AutoCloseable. */
     @Override
-    void close() throws IOException;
+    default void close() throws IOException {
+    };
 }
diff --git a/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java b/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java
index ecdd440..b0f19e2 100644
--- a/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java
+++ b/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java
@@ -129,6 +129,10 @@
         return true;
     }
 
+    public IpPrefix getIpPrefix() {
+        return mIpPrefix;
+    }
+
     /**
      * Check whether or not IA Prefix option has 0 preferred and valid lifetimes.
      */
diff --git a/staticlibs/native/bpfutiljni/com_android_net_module_util_BpfUtils.cpp b/staticlibs/native/bpfutiljni/com_android_net_module_util_BpfUtils.cpp
index cf09379..bcc3ded 100644
--- a/staticlibs/native/bpfutiljni/com_android_net_module_util_BpfUtils.cpp
+++ b/staticlibs/native/bpfutiljni/com_android_net_module_util_BpfUtils.cpp
@@ -30,86 +30,6 @@
 
 using base::unique_fd;
 
-// If attach fails throw error and return false.
-static jboolean com_android_net_module_util_BpfUtil_attachProgramToCgroup(JNIEnv *env,
-        jclass clazz, jint type, jstring bpfProgPath, jstring cgroupPath, jint flags) {
-
-    ScopedUtfChars dirPath(env, cgroupPath);
-    unique_fd cg_fd(open(dirPath.c_str(), O_DIRECTORY | O_RDONLY | O_CLOEXEC));
-    if (cg_fd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "Failed to open the cgroup directory %s: %s",
-                             dirPath.c_str(), strerror(errno));
-        return false;
-    }
-
-    ScopedUtfChars bpfProg(env, bpfProgPath);
-    unique_fd bpf_fd(bpf::retrieveProgram(bpfProg.c_str()));
-    if (bpf_fd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "Failed to retrieve bpf program from %s: %s",
-                             bpfProg.c_str(), strerror(errno));
-        return false;
-    }
-    if (bpf::attachProgram((bpf_attach_type) type, bpf_fd, cg_fd, flags)) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "Failed to attach bpf program %s to %s: %s",
-                             bpfProg.c_str(), dirPath.c_str(), strerror(errno));
-        return false;
-    }
-    return true;
-}
-
-// If detach fails throw error and return false.
-static jboolean com_android_net_module_util_BpfUtil_detachProgramFromCgroup(JNIEnv *env,
-        jclass clazz, jint type, jstring cgroupPath) {
-
-    ScopedUtfChars dirPath(env, cgroupPath);
-    unique_fd cg_fd(open(dirPath.c_str(), O_DIRECTORY | O_RDONLY | O_CLOEXEC));
-    if (cg_fd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "Failed to open the cgroup directory %s: %s",
-                             dirPath.c_str(), strerror(errno));
-        return false;
-    }
-
-    if (bpf::detachProgram((bpf_attach_type) type, cg_fd)) {
-        jniThrowExceptionFmt(env, "Failed to detach bpf program from %s: %s",
-                dirPath.c_str(), strerror(errno));
-        return false;
-    }
-    return true;
-}
-
-// If detach single program fails throw error and return false.
-static jboolean com_android_net_module_util_BpfUtil_detachSingleProgramFromCgroup(JNIEnv *env,
-        jclass clazz, jint type, jstring bpfProgPath, jstring cgroupPath) {
-
-    ScopedUtfChars dirPath(env, cgroupPath);
-    unique_fd cg_fd(open(dirPath.c_str(), O_DIRECTORY | O_RDONLY | O_CLOEXEC));
-    if (cg_fd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "Failed to open the cgroup directory %s: %s",
-                             dirPath.c_str(), strerror(errno));
-        return false;
-    }
-
-    ScopedUtfChars bpfProg(env, bpfProgPath);
-    unique_fd bpf_fd(bpf::retrieveProgram(bpfProg.c_str()));
-    if (bpf_fd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "Failed to retrieve bpf program from %s: %s",
-                             bpfProg.c_str(), strerror(errno));
-        return false;
-    }
-    if (bpf::detachSingleProgram((bpf_attach_type) type, bpf_fd, cg_fd)) {
-        jniThrowExceptionFmt(env, "Failed to detach bpf program %s from %s: %s",
-                bpfProg.c_str(), dirPath.c_str(), strerror(errno));
-        return false;
-    }
-    return true;
-}
-
 static jint com_android_net_module_util_BpfUtil_getProgramIdFromCgroup(JNIEnv *env,
         jclass clazz, jint type, jstring cgroupPath) {
 
@@ -138,12 +58,6 @@
  */
 static const JNINativeMethod gMethods[] = {
     /* name, signature, funcPtr */
-    { "native_attachProgramToCgroup", "(ILjava/lang/String;Ljava/lang/String;I)Z",
-        (void*) com_android_net_module_util_BpfUtil_attachProgramToCgroup },
-    { "native_detachProgramFromCgroup", "(ILjava/lang/String;)Z",
-        (void*) com_android_net_module_util_BpfUtil_detachProgramFromCgroup },
-    { "native_detachSingleProgramFromCgroup", "(ILjava/lang/String;Ljava/lang/String;)Z",
-        (void*) com_android_net_module_util_BpfUtil_detachSingleProgramFromCgroup },
     { "native_getProgramIdFromCgroup", "(ILjava/lang/String;)I",
         (void*) com_android_net_module_util_BpfUtil_getProgramIdFromCgroup },
 };
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 194cec3..11cece1 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -2299,7 +2299,7 @@
         }
 
         @Override
-        public int getBpfProgramId(final int attachType, @NonNull final String cgroupPath) {
+        public int getBpfProgramId(final int attachType) {
             return 0;
         }
 
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsEventLoggerTest.kt b/tests/unit/java/com/android/server/net/NetworkStatsEventLoggerTest.kt
new file mode 100644
index 0000000..9f2d4d3
--- /dev/null
+++ b/tests/unit/java/com/android/server/net/NetworkStatsEventLoggerTest.kt
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2023 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.net
+
+import android.util.IndentingPrintWriter
+import com.android.server.net.NetworkStatsEventLogger.MAX_POLL_REASON
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_DUMPSYS
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_FORCE_UPDATE
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_GLOBAL_ALERT
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_NETWORK_STATUS_CHANGED
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_OPEN_SESSION
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_PERIODIC
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_RAT_CHANGED
+import com.android.server.net.NetworkStatsEventLogger.POLL_REASON_REG_CALLBACK
+import com.android.server.net.NetworkStatsEventLogger.PollEvent
+import com.android.server.net.NetworkStatsEventLogger.PollEvent.pollReasonNameOf
+import com.android.testutils.DevSdkIgnoreRunner
+import java.io.StringWriter
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+
+const val TEST_PERSIST_FLAG = 0x101
+
+@RunWith(DevSdkIgnoreRunner::class)
+class NetworkStatsEventLoggerTest {
+    val logger = NetworkStatsEventLogger()
+    val stringWriter = TestStringWriter()
+    val pw = IndentingPrintWriter(stringWriter)
+
+    @Test
+    fun testDump_invalid() {
+        // Verify it won't crash.
+        logger.dump(pw)
+        // Clear output buffer.
+        stringWriter.getOutputAndClear()
+
+        // Verify log invalid event throws. And nothing output in the dump.
+        val invalidReasons = listOf(-1, MAX_POLL_REASON + 1)
+        invalidReasons.forEach {
+            assertFailsWith<IllegalArgumentException> {
+                logger.logPollEvent(TEST_PERSIST_FLAG, PollEvent(it))
+            }
+            logger.dumpRecentPollEvents(pw)
+            val output = stringWriter.getOutputAndClear()
+            assertStringNotContains(output, pollReasonNameOf(it))
+        }
+    }
+
+    @Test
+    fun testDump_valid() {
+        // Choose arbitrary set of reasons for testing.
+        val loggedReasons = listOf(
+            POLL_REASON_GLOBAL_ALERT,
+            POLL_REASON_FORCE_UPDATE,
+            POLL_REASON_DUMPSYS,
+            POLL_REASON_PERIODIC,
+            POLL_REASON_RAT_CHANGED
+        )
+        val nonLoggedReasons = listOf(
+            POLL_REASON_NETWORK_STATUS_CHANGED,
+            POLL_REASON_OPEN_SESSION,
+            POLL_REASON_REG_CALLBACK)
+
+        // Add some valid records.
+        loggedReasons.forEach {
+            logger.logPollEvent(TEST_PERSIST_FLAG, PollEvent(it))
+        }
+
+        // Collect dumps.
+        logger.dumpRecentPollEvents(pw)
+        val outputRecentEvents = stringWriter.getOutputAndClear()
+        logger.dumpPollCountsPerReason(pw)
+        val outputCountsPerReason = stringWriter.getOutputAndClear()
+
+        // Verify the output contains at least necessary information.
+        loggedReasons.forEach {
+            // Verify all events are shown in the recent event dump.
+            val eventString = PollEvent(it).toString()
+            assertStringContains(outputRecentEvents, TEST_PERSIST_FLAG.toString())
+            assertStringContains(eventString, pollReasonNameOf(it))
+            assertStringContains(outputRecentEvents, eventString)
+            // Verify counts are 1 for each reason.
+            assertCountForReason(outputCountsPerReason, it, 1)
+        }
+
+        // Verify the output remains untouched for other reasons.
+        nonLoggedReasons.forEach {
+            assertStringNotContains(outputRecentEvents, PollEvent(it).toString())
+            assertCountForReason(outputCountsPerReason, it, 0)
+        }
+    }
+
+    @Test
+    fun testDump_maxEventLogs() {
+        // Choose arbitrary reason.
+        val reasonToBeTested = POLL_REASON_PERIODIC
+        val repeatCount = NetworkStatsEventLogger.MAX_EVENTS_LOGS * 2
+
+        // Collect baseline.
+        logger.dumpRecentPollEvents(pw)
+        val lineCountBaseLine = getLineCount(stringWriter.getOutputAndClear())
+
+        repeat(repeatCount) {
+            logger.logPollEvent(TEST_PERSIST_FLAG, PollEvent(reasonToBeTested))
+        }
+
+        // Collect dump.
+        logger.dumpRecentPollEvents(pw)
+        val lineCountAfterTest = getLineCount(stringWriter.getOutputAndClear())
+
+        // Verify line count increment is limited.
+        assertEquals(
+            NetworkStatsEventLogger.MAX_EVENTS_LOGS,
+            lineCountAfterTest - lineCountBaseLine
+        )
+
+        // Verify count per reason increased for the testing reason.
+        logger.dumpPollCountsPerReason(pw)
+        val outputCountsPerReason = stringWriter.getOutputAndClear()
+        for (reason in 0..MAX_POLL_REASON) {
+            assertCountForReason(
+                outputCountsPerReason,
+                reason,
+                if (reason == reasonToBeTested) repeatCount else 0
+            )
+        }
+    }
+
+    private fun getLineCount(multilineString: String) = multilineString.lines().size
+
+    private fun assertStringContains(got: String, want: String) {
+        assertTrue(got.contains(want), "Wanted: $want, but got: $got")
+    }
+
+    private fun assertStringNotContains(got: String, unwant: String) {
+        assertFalse(got.contains(unwant), "Unwanted: $unwant, but got: $got")
+    }
+
+    /**
+     * Assert the reason and the expected count are at the same line.
+     */
+    private fun assertCountForReason(dump: String, reason: Int, expectedCount: Int) {
+        // Matches strings like "GLOBAL_ALERT: 50" but not too strict since the format might change.
+        val regex = Regex(pollReasonNameOf(reason) + "[^0-9]+" + expectedCount)
+        assertEquals(
+            1,
+            regex.findAll(dump).count(),
+            "Unexpected output: $dump " + " for reason: " + pollReasonNameOf(reason)
+        )
+    }
+
+    class TestStringWriter : StringWriter() {
+        fun getOutputAndClear() = toString().also { buffer.setLength(0) }
+    }
+}
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
index 9453617..e8d5c66 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -64,6 +64,8 @@
 import static android.text.format.DateUtils.MINUTE_IN_MILLIS;
 import static android.text.format.DateUtils.WEEK_IN_MILLIS;
 
+import static com.android.server.net.NetworkStatsEventLogger.POLL_REASON_RAT_CHANGED;
+import static com.android.server.net.NetworkStatsEventLogger.PollEvent.pollReasonNameOf;
 import static com.android.server.net.NetworkStatsService.ACTION_NETWORK_STATS_POLL;
 import static com.android.server.net.NetworkStatsService.NETSTATS_IMPORT_ATTEMPTS_COUNTER_NAME;
 import static com.android.server.net.NetworkStatsService.NETSTATS_IMPORT_FALLBACKS_COUNTER_NAME;
@@ -525,6 +527,11 @@
                     IBpfMap<CookieTagMapKey, CookieTagMapValue> cookieTagMap, Handler handler) {
                 return mSkDestroyListener;
             }
+
+            @Override
+            public boolean supportEventLogger(@NonNull Context cts) {
+                return true;
+            }
         };
     }
 
@@ -2674,4 +2681,14 @@
         doReturn(null).when(mBpfInterfaceMapUpdater).getIfNameByIndex(10 /* index */);
         doTestDumpIfaceStatsMap("unknown");
     }
+
+    // Basic test to ensure event logger dump is called.
+    // Note that tests to ensure detailed correctness is done in the dedicated tests.
+    // See NetworkStatsEventLoggerTest.
+    @Test
+    public void testDumpEventLogger() {
+        setMobileRatTypeAndWaitForIdle(TelephonyManager.NETWORK_TYPE_UMTS);
+        final String dump = getDump();
+        assertDumpContains(dump, pollReasonNameOf(POLL_REASON_RAT_CHANGED));
+    }
 }
diff --git a/thread/TEST_MAPPING b/thread/TEST_MAPPING
index 17a74f6..3eaebfa 100644
--- a/thread/TEST_MAPPING
+++ b/thread/TEST_MAPPING
@@ -1,7 +1,5 @@
 {
-  // TODO (b/297729075): graduate this test to presubmit once it meets the SLO requirements.
-  // See go/test-mapping-slo-guide
-  "postsubmit": [
+  "presubmit": [
     {
       "name": "CtsThreadNetworkTestCases"
     }
diff --git a/thread/framework/java/android/net/thread/ThreadNetworkController.java b/thread/framework/java/android/net/thread/ThreadNetworkController.java
index 9db8132..7575757 100644
--- a/thread/framework/java/android/net/thread/ThreadNetworkController.java
+++ b/thread/framework/java/android/net/thread/ThreadNetworkController.java
@@ -34,7 +34,7 @@
 */
 @FlaggedApi(ThreadNetworkFlags.FLAG_THREAD_ENABLED)
 @SystemApi
-public class ThreadNetworkController {
+public final class ThreadNetworkController {
 
     /** Thread standard version 1.3. */
     public static final int THREAD_VERSION_1_3 = 4;
diff --git a/thread/framework/java/android/net/thread/ThreadNetworkManager.java b/thread/framework/java/android/net/thread/ThreadNetworkManager.java
index 3e8288c..c3bdbd7 100644
--- a/thread/framework/java/android/net/thread/ThreadNetworkManager.java
+++ b/thread/framework/java/android/net/thread/ThreadNetworkManager.java
@@ -38,7 +38,7 @@
 @FlaggedApi(ThreadNetworkFlags.FLAG_THREAD_ENABLED)
 @SystemApi
 @SystemService(ThreadNetworkManager.SERVICE_NAME)
-public class ThreadNetworkManager {
+public final class ThreadNetworkManager {
     /**
      * This value tracks {@link Context#THREAD_NETWORK_SERVICE}.
      *
diff --git a/thread/tests/unit/Android.bp b/thread/tests/unit/Android.bp
index 1f16ad1..3a087c7 100644
--- a/thread/tests/unit/Android.bp
+++ b/thread/tests/unit/Android.bp
@@ -38,7 +38,7 @@
         "framework-connectivity-t-pre-jarjar",
         "guava-android-testlib",
         "net-tests-utils",
-        "truth-prebuilt",
+        "truth",
     ],
     libs: [
         "android.test.base",