Refactor NsdManagerTest

Refactor the test to use Kotlin, and move some repeated code to
submethods.

Bug: 190249673
Test: atest NsdManagerTest
Change-Id: Iee7273080d5d29f1d364ac0a77e017edf9b36051
diff --git a/tests/cts/net/src/android/net/cts/NsdManagerTest.java b/tests/cts/net/src/android/net/cts/NsdManagerTest.java
deleted file mode 100644
index 2bcfdc3..0000000
--- a/tests/cts/net/src/android/net/cts/NsdManagerTest.java
+++ /dev/null
@@ -1,594 +0,0 @@
-/*
- * Copyright (C) 2012 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.cts;
-
-import android.content.Context;
-import android.net.nsd.NsdManager;
-import android.net.nsd.NsdServiceInfo;
-import android.platform.test.annotations.AppModeFull;
-import android.test.AndroidTestCase;
-import android.util.Log;
-
-import java.io.IOException;
-import java.net.ServerSocket;
-import java.util.Arrays;
-import java.util.Random;
-import java.util.List;
-import java.util.ArrayList;
-
-@AppModeFull(reason = "Socket cannot bind in instant app mode")
-public class NsdManagerTest extends AndroidTestCase {
-
-    private static final String TAG = "NsdManagerTest";
-    private static final String SERVICE_TYPE = "_nmt._tcp";
-    private static final int TIMEOUT = 2000;
-
-    private static final boolean DBG = false;
-
-    NsdManager mNsdManager;
-
-    NsdManager.RegistrationListener mRegistrationListener;
-    NsdManager.DiscoveryListener mDiscoveryListener;
-    NsdManager.ResolveListener mResolveListener;
-    private NsdServiceInfo mResolvedService;
-
-    public NsdManagerTest() {
-        initRegistrationListener();
-        initDiscoveryListener();
-        initResolveListener();
-    }
-
-    private void initRegistrationListener() {
-        mRegistrationListener = new NsdManager.RegistrationListener() {
-            @Override
-            public void onRegistrationFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                setEvent("onRegistrationFailed", errorCode);
-            }
-
-            @Override
-            public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                setEvent("onUnregistrationFailed", errorCode);
-            }
-
-            @Override
-            public void onServiceRegistered(NsdServiceInfo serviceInfo) {
-                setEvent("onServiceRegistered", serviceInfo);
-            }
-
-            @Override
-            public void onServiceUnregistered(NsdServiceInfo serviceInfo) {
-                setEvent("onServiceUnregistered", serviceInfo);
-            }
-        };
-    }
-
-    private void initDiscoveryListener() {
-        mDiscoveryListener = new NsdManager.DiscoveryListener() {
-            @Override
-            public void onStartDiscoveryFailed(String serviceType, int errorCode) {
-                setEvent("onStartDiscoveryFailed", errorCode);
-            }
-
-            @Override
-            public void onStopDiscoveryFailed(String serviceType, int errorCode) {
-                setEvent("onStopDiscoveryFailed", errorCode);
-            }
-
-            @Override
-            public void onDiscoveryStarted(String serviceType) {
-                NsdServiceInfo info = new NsdServiceInfo();
-                info.setServiceType(serviceType);
-                setEvent("onDiscoveryStarted", info);
-            }
-
-            @Override
-            public void onDiscoveryStopped(String serviceType) {
-                NsdServiceInfo info = new NsdServiceInfo();
-                info.setServiceType(serviceType);
-                setEvent("onDiscoveryStopped", info);
-            }
-
-            @Override
-            public void onServiceFound(NsdServiceInfo serviceInfo) {
-                setEvent("onServiceFound", serviceInfo);
-            }
-
-            @Override
-            public void onServiceLost(NsdServiceInfo serviceInfo) {
-                setEvent("onServiceLost", serviceInfo);
-            }
-        };
-    }
-
-    private void initResolveListener() {
-        mResolveListener = new NsdManager.ResolveListener() {
-            @Override
-            public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                setEvent("onResolveFailed", errorCode);
-            }
-
-            @Override
-            public void onServiceResolved(NsdServiceInfo serviceInfo) {
-                mResolvedService = serviceInfo;
-                setEvent("onServiceResolved", serviceInfo);
-            }
-        };
-    }
-
-
-
-    private final class EventData {
-        EventData(String callbackName, NsdServiceInfo info) {
-            mCallbackName = callbackName;
-            mSucceeded = true;
-            mErrorCode = 0;
-            mInfo = info;
-        }
-        EventData(String callbackName, int errorCode) {
-            mCallbackName = callbackName;
-            mSucceeded = false;
-            mErrorCode = errorCode;
-            mInfo = null;
-        }
-        private final String mCallbackName;
-        private final boolean mSucceeded;
-        private final int mErrorCode;
-        private final NsdServiceInfo mInfo;
-    }
-
-    private final List<EventData> mEventCache = new ArrayList<EventData>();
-
-    private void setEvent(String callbackName, int errorCode) {
-        if (DBG) Log.d(TAG, callbackName + " failed with " + String.valueOf(errorCode));
-        EventData eventData = new EventData(callbackName, errorCode);
-        synchronized (mEventCache) {
-            mEventCache.add(eventData);
-            mEventCache.notify();
-        }
-    }
-
-    private void setEvent(String callbackName, NsdServiceInfo info) {
-        if (DBG) Log.d(TAG, "Received event " + callbackName + " for " + info.getServiceName());
-        EventData eventData = new EventData(callbackName, info);
-        synchronized (mEventCache) {
-            mEventCache.add(eventData);
-            mEventCache.notify();
-        }
-    }
-
-    void clearEventCache() {
-        synchronized(mEventCache) {
-            mEventCache.clear();
-        }
-    }
-
-    int eventCacheSize() {
-        synchronized(mEventCache) {
-            return mEventCache.size();
-        }
-    }
-
-    private int mWaitId = 0;
-    private EventData waitForCallback(String callbackName) {
-
-        synchronized(mEventCache) {
-
-            mWaitId ++;
-            if (DBG) Log.d(TAG, "Waiting for " + callbackName + ", id=" + String.valueOf(mWaitId));
-
-            try {
-                long startTime = android.os.SystemClock.uptimeMillis();
-                long elapsedTime = 0;
-                int index = 0;
-                while (elapsedTime < TIMEOUT ) {
-                    // first check if we've received that event
-                    for (; index < mEventCache.size(); index++) {
-                        EventData e = mEventCache.get(index);
-                        if (e.mCallbackName.equals(callbackName)) {
-                            if (DBG) Log.d(TAG, "exiting wait id=" + String.valueOf(mWaitId));
-                            return e;
-                        }
-                    }
-
-                    // Not yet received, just wait
-                    mEventCache.wait(TIMEOUT - elapsedTime);
-                    elapsedTime = android.os.SystemClock.uptimeMillis() - startTime;
-                }
-                // we exited the loop because of TIMEOUT; fail the call
-                if (DBG) Log.d(TAG, "timed out waiting id=" + String.valueOf(mWaitId));
-                return null;
-            } catch (InterruptedException e) {
-                return null;                       // wait timed out!
-            }
-        }
-    }
-
-    private EventData waitForNewEvents() throws InterruptedException {
-        if (DBG) Log.d(TAG, "Waiting for a bit, id=" + String.valueOf(mWaitId));
-
-        long startTime = android.os.SystemClock.uptimeMillis();
-        long elapsedTime = 0;
-        synchronized (mEventCache) {
-            int index = mEventCache.size();
-            while (elapsedTime < TIMEOUT ) {
-                // first check if we've received that event
-                for (; index < mEventCache.size(); index++) {
-                    EventData e = mEventCache.get(index);
-                    return e;
-                }
-
-                // Not yet received, just wait
-                mEventCache.wait(TIMEOUT - elapsedTime);
-                elapsedTime = android.os.SystemClock.uptimeMillis() - startTime;
-            }
-        }
-
-        return null;
-    }
-
-    private String mServiceName;
-
-    @Override
-    public void setUp() throws Exception {
-        super.setUp();
-        if (DBG) Log.d(TAG, "Setup test ...");
-        mNsdManager = (NsdManager) getContext().getSystemService(Context.NSD_SERVICE);
-
-        Random rand = new Random();
-        mServiceName = new String("NsdTest");
-        for (int i = 0; i < 4; i++) {
-            mServiceName = mServiceName + String.valueOf(rand.nextInt(10));
-        }
-    }
-
-    @Override
-    public void tearDown() throws Exception {
-        if (DBG) Log.d(TAG, "Tear down test ...");
-        super.tearDown();
-    }
-
-    public void testNDSManager() throws Exception {
-        EventData lastEvent = null;
-
-        if (DBG) Log.d(TAG, "Starting test ...");
-
-        NsdServiceInfo si = new NsdServiceInfo();
-        si.setServiceType(SERVICE_TYPE);
-        si.setServiceName(mServiceName);
-
-        byte testByteArray[] = new byte[] {-128, 127, 2, 1, 0, 1, 2};
-        String String256 = "1_________2_________3_________4_________5_________6_________" +
-                 "7_________8_________9_________10________11________12________13________" +
-                 "14________15________16________17________18________19________20________" +
-                 "21________22________23________24________25________123456";
-
-        // Illegal attributes
-        try {
-            si.setAttribute(null, (String) null);
-            fail("Could set null key");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute("", (String) null);
-            fail("Could set empty key");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute(String256, (String) null);
-            fail("Could set key with 255 characters");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute("key", String256.substring(3));
-            fail("Could set key+value combination with more than 255 characters");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute("key", String256.substring(4));
-            fail("Could set key+value combination with 255 characters");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute(new String(new byte[]{0x19}), (String) null);
-            fail("Could set key with invalid character");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute("=", (String) null);
-            fail("Could set key with invalid character");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        try {
-            si.setAttribute(new String(new byte[]{0x7F}), (String) null);
-            fail("Could set key with invalid character");
-        } catch (IllegalArgumentException e) {
-            // expected
-        }
-
-        // Allowed attributes
-        si.setAttribute("booleanAttr", (String) null);
-        si.setAttribute("keyValueAttr", "value");
-        si.setAttribute("keyEqualsAttr", "=");
-        si.setAttribute(" whiteSpaceKeyValueAttr ", " value ");
-        si.setAttribute("binaryDataAttr", testByteArray);
-        si.setAttribute("nullBinaryDataAttr", (byte[]) null);
-        si.setAttribute("emptyBinaryDataAttr", new byte[]{});
-        si.setAttribute("longkey", String256.substring(9));
-
-        ServerSocket socket;
-        int localPort;
-
-        try {
-            socket = new ServerSocket(0);
-            localPort = socket.getLocalPort();
-            si.setPort(localPort);
-        } catch (IOException e) {
-            if (DBG) Log.d(TAG, "Could not open a local socket");
-            assertTrue(false);
-            return;
-        }
-
-        if (DBG) Log.d(TAG, "Port = " + String.valueOf(localPort));
-
-        clearEventCache();
-
-        mNsdManager.registerService(si, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
-        lastEvent = waitForCallback("onServiceRegistered");                 // id = 1
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-        assertTrue(eventCacheSize() == 1);
-
-        // We may not always get the name that we tried to register;
-        // This events tells us the name that was registered.
-        String registeredName = lastEvent.mInfo.getServiceName();
-        si.setServiceName(registeredName);
-
-        clearEventCache();
-
-        mNsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
-                mDiscoveryListener);
-
-        // Expect discovery started
-        lastEvent = waitForCallback("onDiscoveryStarted");                  // id = 2
-
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-
-        // Remove this event, so accounting becomes easier later
-        synchronized (mEventCache) {
-            mEventCache.remove(lastEvent);
-        }
-
-        // Expect a service record to be discovered (and filter the ones
-        // that are unrelated to this test)
-        boolean found = false;
-        for (int i = 0; i < 32; i++) {
-
-            lastEvent = waitForCallback("onServiceFound");                  // id = 3
-            if (lastEvent == null) {
-                // no more onServiceFound events are being reported!
-                break;
-            }
-
-            assertTrue(lastEvent.mSucceeded);
-
-            if (DBG) Log.d(TAG, "id = " + String.valueOf(mWaitId) + ": ServiceName = " +
-                    lastEvent.mInfo.getServiceName());
-
-            if (lastEvent.mInfo.getServiceName().equals(registeredName)) {
-                // Save it, as it will get overwritten with new serviceFound events
-                si = lastEvent.mInfo;
-                found = true;
-            }
-
-            // Remove this event from the event cache, so it won't be found by subsequent
-            // calls to waitForCallback
-            synchronized (mEventCache) {
-                mEventCache.remove(lastEvent);
-            }
-        }
-
-        assertTrue(found);
-
-        // We've removed all serviceFound events, and we've removed the discoveryStarted
-        // event as well, so now the event cache should be empty!
-        assertTrue(eventCacheSize() == 0);
-
-        // Resolve the service
-        clearEventCache();
-        mNsdManager.resolveService(si, mResolveListener);
-        lastEvent = waitForCallback("onServiceResolved");                   // id = 4
-
-        assertNotNull(mResolvedService);
-
-        // Check Txt attributes
-        assertEquals(8, mResolvedService.getAttributes().size());
-        assertTrue(mResolvedService.getAttributes().containsKey("booleanAttr"));
-        assertNull(mResolvedService.getAttributes().get("booleanAttr"));
-        assertEquals("value", new String(mResolvedService.getAttributes().get("keyValueAttr")));
-        assertEquals("=", new String(mResolvedService.getAttributes().get("keyEqualsAttr")));
-        assertEquals(" value ", new String(mResolvedService.getAttributes()
-                .get(" whiteSpaceKeyValueAttr ")));
-        assertEquals(String256.substring(9), new String(mResolvedService.getAttributes()
-                .get("longkey")));
-        assertTrue(Arrays.equals(testByteArray,
-                mResolvedService.getAttributes().get("binaryDataAttr")));
-        assertTrue(mResolvedService.getAttributes().containsKey("nullBinaryDataAttr"));
-        assertNull(mResolvedService.getAttributes().get("nullBinaryDataAttr"));
-        assertTrue(mResolvedService.getAttributes().containsKey("emptyBinaryDataAttr"));
-        assertNull(mResolvedService.getAttributes().get("emptyBinaryDataAttr"));
-
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-
-        if (DBG) Log.d(TAG, "id = " + String.valueOf(mWaitId) + ": Port = " +
-                String.valueOf(lastEvent.mInfo.getPort()));
-
-        assertTrue(lastEvent.mInfo.getPort() == localPort);
-        assertTrue(eventCacheSize() == 1);
-
-        checkForAdditionalEvents();
-        clearEventCache();
-
-        // Unregister the service
-        mNsdManager.unregisterService(mRegistrationListener);
-        lastEvent = waitForCallback("onServiceUnregistered");               // id = 5
-
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-
-        // Expect a callback for service lost
-        lastEvent = waitForCallback("onServiceLost");                       // id = 6
-
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mInfo.getServiceName().equals(registeredName));
-
-        // Register service again to see if we discover it
-        checkForAdditionalEvents();
-        clearEventCache();
-
-        si = new NsdServiceInfo();
-        si.setServiceType(SERVICE_TYPE);
-        si.setServiceName(mServiceName);
-        si.setPort(localPort);
-
-        // Create a new registration listener and register same service again
-        initRegistrationListener();
-
-        mNsdManager.registerService(si, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
-
-        lastEvent = waitForCallback("onServiceRegistered");                 // id = 7
-
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-
-        registeredName = lastEvent.mInfo.getServiceName();
-
-        // Expect a record to be discovered
-        // Expect a service record to be discovered (and filter the ones
-        // that are unrelated to this test)
-        found = false;
-        for (int i = 0; i < 32; i++) {
-
-            lastEvent = waitForCallback("onServiceFound");                  // id = 8
-            if (lastEvent == null) {
-                // no more onServiceFound events are being reported!
-                break;
-            }
-
-            assertTrue(lastEvent.mSucceeded);
-
-            if (DBG) Log.d(TAG, "id = " + String.valueOf(mWaitId) + ": ServiceName = " +
-                    lastEvent.mInfo.getServiceName());
-
-            if (lastEvent.mInfo.getServiceName().equals(registeredName)) {
-                // Save it, as it will get overwritten with new serviceFound events
-                si = lastEvent.mInfo;
-                found = true;
-            }
-
-            // Remove this event from the event cache, so it won't be found by subsequent
-            // calls to waitForCallback
-            synchronized (mEventCache) {
-                mEventCache.remove(lastEvent);
-            }
-        }
-
-        assertTrue(found);
-
-        // Resolve the service
-        clearEventCache();
-        mNsdManager.resolveService(si, mResolveListener);
-        lastEvent = waitForCallback("onServiceResolved");                   // id = 9
-
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-
-        if (DBG) Log.d(TAG, "id = " + String.valueOf(mWaitId) + ": ServiceName = " +
-                lastEvent.mInfo.getServiceName());
-
-        assertTrue(lastEvent.mInfo.getServiceName().equals(registeredName));
-
-        assertNotNull(mResolvedService);
-
-        // Check that we don't have any TXT records
-        assertEquals(0, mResolvedService.getAttributes().size());
-
-        checkForAdditionalEvents();
-        clearEventCache();
-
-        mNsdManager.stopServiceDiscovery(mDiscoveryListener);
-        lastEvent = waitForCallback("onDiscoveryStopped");                  // id = 10
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-        assertTrue(checkCacheSize(1));
-
-        checkForAdditionalEvents();
-        clearEventCache();
-
-        mNsdManager.unregisterService(mRegistrationListener);
-
-        lastEvent =  waitForCallback("onServiceUnregistered");              // id = 11
-        assertTrue(lastEvent != null);
-        assertTrue(lastEvent.mSucceeded);
-        assertTrue(checkCacheSize(1));
-    }
-
-    boolean checkCacheSize(int size) {
-        synchronized (mEventCache) {
-            int cacheSize = mEventCache.size();
-            if (cacheSize != size) {
-                Log.d(TAG, "id = " + mWaitId + ": event cache size = " + cacheSize);
-                for (int i = 0; i < cacheSize; i++) {
-                    EventData e = mEventCache.get(i);
-                    String sname = (e.mInfo != null) ? "(" + e.mInfo.getServiceName() + ")" : "";
-                    Log.d(TAG, "eventName is " + e.mCallbackName + sname);
-                }
-            }
-            return (cacheSize == size);
-        }
-    }
-
-    boolean checkForAdditionalEvents() {
-        try {
-            EventData e = waitForNewEvents();
-            if (e != null) {
-                String sname = (e.mInfo != null) ? "(" + e.mInfo.getServiceName() + ")" : "";
-                Log.d(TAG, "ignoring unexpected event " + e.mCallbackName + sname);
-            }
-            return (e == null);
-        }
-        catch (InterruptedException ex) {
-            return false;
-        }
-    }
-}
-
diff --git a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
new file mode 100644
index 0000000..8daf720
--- /dev/null
+++ b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
@@ -0,0 +1,422 @@
+/*
+ * Copyright (C) 2012 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.cts
+
+import android.net.nsd.NsdManager
+import android.net.nsd.NsdManager.DiscoveryListener
+import android.net.nsd.NsdManager.ResolveListener
+import android.net.nsd.NsdServiceInfo
+import android.os.SystemClock
+import android.platform.test.annotations.AppModeFull
+import android.util.Log
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.runner.AndroidJUnit4
+import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+import java.net.ServerSocket
+import java.nio.charset.StandardCharsets
+import java.util.Random
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+import kotlin.test.fail
+
+private const val TAG = "NsdManagerTest"
+private const val SERVICE_TYPE = "_nmt._tcp"
+private const val TIMEOUT = 2000
+private const val DBG = false
+
+@AppModeFull(reason = "Socket cannot bind in instant app mode")
+@RunWith(AndroidJUnit4::class)
+class NsdManagerTest {
+    private val context by lazy { InstrumentationRegistry.getInstrumentation().context }
+    private val nsdManager by lazy { context.getSystemService(NsdManager::class.java) }
+    private val serviceName = "NsdTest%04d".format(Random().nextInt(1000))
+
+    private val registrationListener = object : NsdManager.RegistrationListener {
+        override fun onRegistrationFailed(serviceInfo: NsdServiceInfo, errorCode: Int) {
+            setEvent("onRegistrationFailed", errorCode)
+        }
+
+        override fun onUnregistrationFailed(serviceInfo: NsdServiceInfo, errorCode: Int) {
+            setEvent("onUnregistrationFailed", errorCode)
+        }
+
+        override fun onServiceRegistered(serviceInfo: NsdServiceInfo) {
+            setEvent("onServiceRegistered", serviceInfo)
+        }
+
+        override fun onServiceUnregistered(serviceInfo: NsdServiceInfo) {
+            setEvent("onServiceUnregistered", serviceInfo)
+        }
+    }
+
+    private val discoveryListener = object : DiscoveryListener {
+        override fun onStartDiscoveryFailed(serviceType: String, errorCode: Int) {
+            setEvent("onStartDiscoveryFailed", errorCode)
+        }
+
+        override fun onStopDiscoveryFailed(serviceType: String, errorCode: Int) {
+            setEvent("onStopDiscoveryFailed", errorCode)
+        }
+
+        override fun onDiscoveryStarted(serviceType: String) {
+            val info = NsdServiceInfo()
+            info.serviceType = serviceType
+            setEvent("onDiscoveryStarted", info)
+        }
+
+        override fun onDiscoveryStopped(serviceType: String) {
+            val info = NsdServiceInfo()
+            info.serviceType = serviceType
+            setEvent("onDiscoveryStopped", info)
+        }
+
+        override fun onServiceFound(serviceInfo: NsdServiceInfo) {
+            setEvent("onServiceFound", serviceInfo)
+        }
+
+        override fun onServiceLost(serviceInfo: NsdServiceInfo) {
+            setEvent("onServiceLost", serviceInfo)
+        }
+    }
+
+    private inner class TestResolveListener : ResolveListener {
+        var resolvedService: NsdServiceInfo? = null
+        override fun onResolveFailed(serviceInfo: NsdServiceInfo, errorCode: Int) {
+            setEvent("onResolveFailed", errorCode)
+        }
+
+        override fun onServiceResolved(serviceInfo: NsdServiceInfo) {
+            resolvedService = serviceInfo
+            setEvent("onServiceResolved", serviceInfo)
+        }
+    }
+
+    private class EventData {
+        constructor(callbackName: String, info: NsdServiceInfo?) {
+            this.callbackName = callbackName
+            succeeded = true
+            errorCode = 0
+            this.info = info
+        }
+
+        constructor(callbackName: String, errorCode: Int) {
+            this.callbackName = callbackName
+            succeeded = false
+            this.errorCode = errorCode
+            info = null
+        }
+
+        val callbackName: String
+        val succeeded: Boolean
+        private val errorCode: Int
+        val info: NsdServiceInfo?
+    }
+
+    private val eventCache = ArrayList<EventData>()
+    private fun setEvent(callbackName: String, errorCode: Int) {
+        if (DBG) Log.d(TAG, "$callbackName failed with $errorCode")
+        val eventData = EventData(callbackName, errorCode)
+        synchronized(eventCache) {
+            eventCache.add(eventData)
+            eventCache.notify()
+        }
+    }
+
+    private fun setEvent(callbackName: String, info: NsdServiceInfo) {
+        if (DBG) Log.d(TAG, "Received event " + callbackName + " for " + info.serviceName)
+        val eventData = EventData(callbackName, info)
+        synchronized(eventCache) {
+            eventCache.add(eventData)
+            eventCache.notify()
+        }
+    }
+
+    fun clearEventCache() {
+        synchronized(eventCache) { eventCache.clear() }
+    }
+
+    fun eventCacheSize(): Int {
+        synchronized(eventCache) { return eventCache.size }
+    }
+
+    private var waitId = 0
+    private fun waitForCallback(callbackName: String): EventData? {
+        synchronized(eventCache) {
+            waitId++
+            if (DBG) Log.d(TAG, "Waiting for $callbackName, id=$waitId")
+            val startTime = SystemClock.uptimeMillis()
+            var elapsedTime = 0L
+            while (elapsedTime < TIMEOUT) {
+                // first check if we've received that event
+                eventCache.find { it.callbackName == callbackName }?.let {
+                    if (DBG) Log.d(TAG, "exiting wait id=$waitId")
+                    return it
+                }
+
+                // Not yet received, just wait
+                try {
+                    eventCache.wait(TIMEOUT - elapsedTime)
+                } catch (e: InterruptedException) {
+                    return null
+                }
+                elapsedTime = SystemClock.uptimeMillis() - startTime
+            }
+            // we exited the loop because of TIMEOUT; fail the call
+            if (DBG) Log.d(TAG, "timed out waiting id=$waitId")
+            return null
+        }
+    }
+
+    private fun waitForNewEvents(): EventData? {
+        if (DBG) Log.d(TAG, "Waiting for a bit, id=$waitId")
+        val startTime = SystemClock.uptimeMillis()
+        var elapsedTime = 0L
+        synchronized(eventCache) {
+            val index = eventCache.size
+            while (elapsedTime < TIMEOUT) {
+                // first check if we've received that event
+                if (index < eventCache.size) {
+                    return eventCache[index]
+                }
+
+                // Not yet received, just wait
+                eventCache.wait(TIMEOUT - elapsedTime)
+                elapsedTime = SystemClock.uptimeMillis() - startTime
+            }
+        }
+        return null
+    }
+
+    @Test
+    fun testNsdManager() {
+        val si = NsdServiceInfo()
+        si.serviceType = SERVICE_TYPE
+        si.serviceName = serviceName
+        val testByteArray = byteArrayOf(-128, 127, 2, 1, 0, 1, 2)
+        val string256 = "1_________2_________3_________4_________5_________6_________" +
+                "7_________8_________9_________10________11________12________13________" +
+                "14________15________16________17________18________19________20________" +
+                "21________22________23________24________25________123456"
+
+        // Illegal attributes
+        assertFailsWith<IllegalArgumentException>("Could set null key") {
+            si.setAttribute(null, null as String?)
+        }
+        assertFailsWith<IllegalArgumentException>("Could set empty key") {
+            si.setAttribute("", null as String?)
+        }
+        assertFailsWith<IllegalArgumentException>("Could set key with 255 characters") {
+            si.setAttribute(string256, null as String?)
+        }
+        assertFailsWith<IllegalArgumentException>(
+                "Could set key+value combination with more than 255 characters") {
+            si.setAttribute("key", string256.substring(3))
+        }
+        assertFailsWith<IllegalArgumentException>(
+                "Could set key+value combination with 255 characters") {
+            si.setAttribute("key", string256.substring(4))
+        }
+        assertFailsWith<IllegalArgumentException>("Could set key with invalid character") {
+            si.setAttribute("\u0019", null as String?)
+        }
+        assertFailsWith<IllegalArgumentException>("Could set key with invalid character") {
+            si.setAttribute("=", null as String?)
+        }
+        assertFailsWith<IllegalArgumentException>("Could set key with invalid character") {
+            si.setAttribute("\u007f", null as String?)
+        }
+
+        // Allowed attributes
+        si.setAttribute("booleanAttr", null as String?)
+        si.setAttribute("keyValueAttr", "value")
+        si.setAttribute("keyEqualsAttr", "=")
+        si.setAttribute(" whiteSpaceKeyValueAttr ", " value ")
+        si.setAttribute("binaryDataAttr", testByteArray)
+        si.setAttribute("nullBinaryDataAttr", null as ByteArray?)
+        si.setAttribute("emptyBinaryDataAttr", byteArrayOf())
+        si.setAttribute("longkey", string256.substring(9))
+        val socket = ServerSocket(0)
+        val localPort = socket.localPort
+        si.port = localPort
+        if (DBG) Log.d(TAG, "Port = $localPort")
+        clearEventCache()
+
+        val registeredName = registerService(si)
+
+        assertEquals(1, eventCacheSize())
+        clearEventCache()
+        nsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, discoveryListener)
+
+        // Expect discovery started
+        var lastEvent = waitForCallback("onDiscoveryStarted")
+        assertNotNull(lastEvent)
+        assertTrue(lastEvent.succeeded)
+
+        // Remove this event, so accounting becomes easier later
+        synchronized(eventCache) { eventCache.remove(lastEvent) }
+
+        // Expect a service record to be discovered
+        val foundInfo = waitForServiceDiscovered(registeredName)
+
+        // We've removed all serviceFound events, and we've removed the discoveryStarted
+        // event as well, so now the event cache should be empty!
+        assertEquals(0, eventCacheSize())
+
+        val resolvedService = resolveService(foundInfo)
+
+        // Check Txt attributes
+        assertEquals(8, resolvedService.attributes.size)
+        assertTrue(resolvedService.attributes.containsKey("booleanAttr"))
+        assertNull(resolvedService.attributes["booleanAttr"])
+        assertEquals("value", resolvedService.attributes["keyValueAttr"].utf8ToString())
+        assertEquals("=", resolvedService.attributes["keyEqualsAttr"].utf8ToString())
+        assertEquals(" value ",
+                resolvedService.attributes[" whiteSpaceKeyValueAttr "].utf8ToString())
+        assertEquals(string256.substring(9), resolvedService.attributes["longkey"].utf8ToString())
+        assertArrayEquals(testByteArray, resolvedService.attributes["binaryDataAttr"])
+        assertTrue(resolvedService.attributes.containsKey("nullBinaryDataAttr"))
+        assertNull(resolvedService.attributes["nullBinaryDataAttr"])
+        assertTrue(resolvedService.attributes.containsKey("emptyBinaryDataAttr"))
+        assertNull(resolvedService.attributes["emptyBinaryDataAttr"])
+        if (DBG) Log.d(TAG, "id = $waitId: Port = ${lastEvent.info?.port}")
+        assertEquals(localPort, resolvedService.port)
+        assertEquals(1, eventCacheSize())
+        checkForAdditionalEvents()
+        clearEventCache()
+
+        // Unregister the service
+        nsdManager.unregisterService(registrationListener)
+        lastEvent = waitForCallback("onServiceUnregistered")
+        assertNotNull(lastEvent)
+        assertTrue(lastEvent.succeeded)
+
+        // Expect a callback for service lost
+        lastEvent = waitForCallback("onServiceLost")
+        assertNotNull(lastEvent)
+        assertEquals(registeredName, lastEvent.info?.serviceName)
+
+        // Register service again to see if we discover it
+        checkForAdditionalEvents()
+        clearEventCache()
+        val si2 = NsdServiceInfo()
+        si2.serviceType = SERVICE_TYPE
+        si2.serviceName = serviceName
+        si2.port = localPort
+        val registeredName2 = registerService(si2)
+
+        // Expect a record to be discovered
+        // Expect a service record to be discovered (and filter the ones
+        // that are unrelated to this test)
+        val foundInfo2 = waitForServiceDiscovered(registeredName2)
+
+        // Resolve the service
+        clearEventCache()
+        val resolvedService2 = resolveService(foundInfo2)
+
+        // Check that we don't have any TXT records
+        assertEquals(0, resolvedService2.attributes.size)
+        checkForAdditionalEvents()
+        clearEventCache()
+        nsdManager.stopServiceDiscovery(discoveryListener)
+        lastEvent = waitForCallback("onDiscoveryStopped")
+        assertNotNull(lastEvent)
+        assertTrue(lastEvent.succeeded)
+        checkCacheSize(1)
+        checkForAdditionalEvents()
+        clearEventCache()
+        nsdManager.unregisterService(registrationListener)
+        lastEvent = waitForCallback("onServiceUnregistered")
+        assertNotNull(lastEvent)
+        assertTrue(lastEvent.succeeded)
+        checkCacheSize(1)
+    }
+
+    /**
+     * Register a service and return its registered name.
+     */
+    private fun registerService(si: NsdServiceInfo): String {
+        nsdManager.registerService(si, NsdManager.PROTOCOL_DNS_SD, registrationListener)
+
+        // We may not always get the name that we tried to register;
+        // This events tells us the name that was registered.
+        val cb = waitForCallback("onServiceRegistered")
+        assertNotNull(cb)
+        assertTrue(cb.succeeded)
+        return cb.info?.serviceName ?: fail("Missing event info")
+    }
+
+    private fun waitForServiceDiscovered(serviceName: String): NsdServiceInfo {
+        var foundInfo: NsdServiceInfo? = null
+        repeat(32) {
+            val event = waitForCallback("onServiceFound") ?: return@repeat
+            assertTrue(event.succeeded)
+            if (DBG) Log.d(TAG, "id = $waitId: ServiceName = ${event.info?.serviceName}")
+            if (event.info?.serviceName == serviceName) {
+                // Save it, as it will get overwritten with new serviceFound events
+                foundInfo = event.info
+            }
+
+            // Remove this event from the event cache, so it won't be found by subsequent
+            // calls to waitForCallback
+            synchronized(eventCache) { eventCache.remove(event) }
+        }
+        return foundInfo ?: fail("Service not discovered")
+    }
+
+    private fun resolveService(discoveredInfo: NsdServiceInfo): NsdServiceInfo {
+        val resolveListener = TestResolveListener()
+        nsdManager.resolveService(discoveredInfo, resolveListener)
+        val resolvedCb = waitForCallback("onServiceResolved")
+        assertNotNull(resolvedCb)
+        assertTrue(resolvedCb.succeeded)
+        if (DBG) Log.d(TAG, "id = $waitId: ServiceName = ${resolvedCb.info?.serviceName}")
+        assertEquals(discoveredInfo.serviceName, resolvedCb.info?.serviceName)
+
+        return resolveListener.resolvedService ?: fail("Missing resolved service")
+    }
+
+    fun checkCacheSize(size: Int) {
+        synchronized(eventCache) {
+            if (size != eventCache.size) {
+                fail("Expected size $size, found event list [${
+                    eventCache.joinToString(", ") {
+                        "eventName: ${it.callbackName}, serviceName ${it.info?.serviceName}"
+                    }
+                }]")
+            }
+        }
+    }
+
+    fun checkForAdditionalEvents(): Boolean {
+        val e = waitForNewEvents() ?: return true
+        Log.d(TAG, "ignoring unexpected event ${e.callbackName} (${e.info?.serviceName})")
+        return false
+    }
+}
+
+private fun ByteArray?.utf8ToString(): String {
+    if (this == null) return ""
+    return String(this, StandardCharsets.UTF_8)
+}
+
+// TODO: migrate legacy java-style implementation to newer utils like RecorderCallback
+private fun Any.wait(timeout: Long) = (this as Object).wait(timeout)
+private fun Any.notify() = (this as Object).notify()
\ No newline at end of file