Call.addEventListener (#9181)

* Call.addEventListener Use this to install listeners after-the-fact, such as in Interceptors or other EventListeners. * apiDump * Make eventListener updates atomic * Fix
2026-01-12 10:23:16 +03:00 · 2025-11-05 13:28:35 -05:00
parent c3f052fd94
commit e6b7eeee4b
11 changed files with 274 additions and 93 deletions
--- a/okhttp-testing-support/src/main/kotlin/okhttp3/EventListenerRelay.kt
+++ b/okhttp-testing-support/src/main/kotlin/okhttp3/EventListenerRelay.kt
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2025 Square, Inc.
+ *
+ * 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 okhttp3
+
+/**
+ * A special [EventListener] for testing the mechanics of event listeners.
+ *
+ * Each instance processes a single event on [call], and then adds a successor [EventListenerRelay]
+ * on the same [call] to process the next event.
+ *
+ * By forcing the list of listeners to change after every event, we can detect if buggy code caches
+ * a stale [EventListener] in a field or local variable.
+ */
+class EventListenerRelay(
+  val call: Call,
+  val eventRecorder: EventRecorder,
+) {
+  private val eventListenerAdapter =
+    EventListenerAdapter()
+      .apply {
+        listeners += ::onEvent
+      }
+
+  val eventListener: EventListener
+    get() = eventListenerAdapter
+
+  var eventCount = 0
+
+  private fun onEvent(callEvent: CallEvent) {
+    if (eventCount++ == 0) {
+      eventRecorder.logEvent(callEvent)
+      val next = EventListenerRelay(call, eventRecorder)
+      call.addEventListener(next.eventListener)
+    }
+  }
+}
--- a/okhttp-testing-support/src/main/kotlin/okhttp3/EventRecorder.kt
+++ b/okhttp-testing-support/src/main/kotlin/okhttp3/EventRecorder.kt
@@ -120,7 +120,7 @@ open class EventRecorder(
    }
  }

-  private fun logEvent(e: CallEvent) {
+  internal fun logEvent(e: CallEvent) {
    for (lock in forbiddenLocks) {
      assertThat(Thread.holdsLock(lock), lock.toString()).isFalse()
    }
--- a/okhttp-testing-support/src/main/kotlin/okhttp3/FailingCall.kt
+++ b/okhttp-testing-support/src/main/kotlin/okhttp3/FailingCall.kt
@@ -33,6 +33,8 @@ open class FailingCall : Call {

  override fun timeout(): Timeout = error("unexpected")

+  override fun addEventListener(eventListener: EventListener) = error("unexpected")
+
  override fun <T : Any> tag(type: KClass<T>): T? = error("unexpected")

  override fun <T> tag(type: Class<out T>): T? = error("unexpected")
--- a/okhttp/api/android/okhttp.api
+++ b/okhttp/api/android/okhttp.api
@@ -119,6 +119,7 @@ public final class okhttp3/CacheControl$Companion {
 }

 public abstract interface class okhttp3/Call : java/lang/Cloneable {
+	public abstract fun addEventListener (Lokhttp3/EventListener;)V
 	public abstract fun cancel ()V
 	public abstract fun clone ()Lokhttp3/Call;
 	public abstract fun enqueue (Lokhttp3/Callback;)V
--- a/okhttp/api/jvm/okhttp.api
+++ b/okhttp/api/jvm/okhttp.api
@@ -119,6 +119,7 @@ public final class okhttp3/CacheControl$Companion {
 }

 public abstract interface class okhttp3/Call : java/lang/Cloneable {
+	public abstract fun addEventListener (Lokhttp3/EventListener;)V
 	public abstract fun cancel ()V
 	public abstract fun clone ()Lokhttp3/Call;
 	public abstract fun enqueue (Lokhttp3/Callback;)V
--- a/okhttp/src/commonJvmAndroid/kotlin/okhttp3/Call.kt
+++ b/okhttp/src/commonJvmAndroid/kotlin/okhttp3/Call.kt
@@ -88,6 +88,19 @@ interface Call : Cloneable {
   */
  fun timeout(): Timeout

+  /**
+   * Configure this call to publish all future events to [eventListener], in addition to the
+   * listeners configured by [OkHttpClient.Builder.eventListener] and other calls to this function.
+   *
+   * If this call is later [cloned][clone], [eventListener] will not be notified of its events.
+   *
+   * There is no mechanism to remove an event listener. Implementations should instead ignore events
+   * that they are not interested in.
+   *
+   * @see EventListener for semantics and restrictions on listener implementations.
+   */
+  fun addEventListener(eventListener: EventListener)
+
  /**
   * Returns the tag attached with [type] as a key, or null if no tag is attached with that key.
   *
@@ -161,6 +174,9 @@ interface Call : Cloneable {
   *   copy.tag(MyTag.class, () -> myTag);
   * }
   * ```
+   *
+   * If any event listeners were installed on this call with [addEventListener], they will not be
+   * installed on this copy.
   */
  public override fun clone(): Call

--- a/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/cache/CacheInterceptor.kt
+++ b/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/cache/CacheInterceptor.kt
@@ -21,7 +21,6 @@ import java.net.HttpURLConnection.HTTP_GATEWAY_TIMEOUT
 import java.net.HttpURLConnection.HTTP_NOT_MODIFIED
 import java.util.concurrent.TimeUnit.MILLISECONDS
 import okhttp3.Cache
-import okhttp3.EventListener
 import okhttp3.Headers
 import okhttp3.Interceptor
 import okhttp3.Protocol
@@ -42,11 +41,11 @@ import okio.buffer

 /** Serves requests from the cache and writes responses to the cache. */
 class CacheInterceptor(
+  internal val call: RealCall,
  internal val cache: Cache?,
 ) : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {
-    val call = chain.call()
    val cacheCandidate = cache?.get(chain.request().requestForCache())

    val now = System.currentTimeMillis()
@@ -56,7 +55,6 @@ class CacheInterceptor(
    val cacheResponse = strategy.cacheResponse

    cache?.trackResponse(strategy)
-    val listener = (call as? RealCall)?.eventListener ?: EventListener.NONE

    if (cacheCandidate != null && cacheResponse == null) {
      // The cache candidate wasn't applicable. Close it.
@@ -75,7 +73,7 @@ class CacheInterceptor(
        .receivedResponseAtMillis(System.currentTimeMillis())
        .build()
        .also {
-          listener.satisfactionFailure(call, it)
+          call.eventListener.satisfactionFailure(call, it)
        }
    }

@@ -86,14 +84,14 @@ class CacheInterceptor(
        .cacheResponse(cacheResponse.stripBody())
        .build()
        .also {
-          listener.cacheHit(call, it)
+          call.eventListener.cacheHit(call, it)
        }
    }

    if (cacheResponse != null) {
-      listener.cacheConditionalHit(call, cacheResponse)
+      call.eventListener.cacheConditionalHit(call, cacheResponse)
    } else if (cache != null) {
-      listener.cacheMiss(call)
+      call.eventListener.cacheMiss(call)
    }

    var networkResponse: Response? = null
@@ -126,7 +124,7 @@ class CacheInterceptor(
        cache!!.trackConditionalCacheHit()
        cache.update(cacheResponse, response)
        return response.also {
-          listener.cacheHit(call, it)
+          call.eventListener.cacheHit(call, it)
        }
      } else {
        cacheResponse.body.closeQuietly()
@@ -149,7 +147,7 @@ class CacheInterceptor(
        return cacheWritingResponse(cacheRequest, response).also {
          if (cacheResponse != null) {
            // This will log a conditional cache miss only.
-            listener.cacheMiss(call)
+            call.eventListener.cacheMiss(call)
          }
        }
      }
--- a/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/Exchange.kt
+++ b/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/Exchange.kt
@@ -38,7 +38,6 @@ import okio.buffer
 */
 class Exchange(
  internal val call: RealCall,
-  internal val eventListener: EventListener,
  internal val finder: ExchangeFinder,
  private val codec: ExchangeCodec,
 ) {
@@ -59,11 +58,11 @@ class Exchange(
  @Throws(IOException::class)
  fun writeRequestHeaders(request: Request) {
    try {
-      eventListener.requestHeadersStart(call)
+      call.eventListener.requestHeadersStart(call)
      codec.writeRequestHeaders(request)
-      eventListener.requestHeadersEnd(call, request)
+      call.eventListener.requestHeadersEnd(call, request)
    } catch (e: IOException) {
-      eventListener.requestFailed(call, e)
+      call.eventListener.requestFailed(call, e)
      trackFailure(e)
      throw e
    }
@@ -76,7 +75,7 @@ class Exchange(
  ): Sink {
    this.isDuplex = duplex
    val contentLength = request.body!!.contentLength()
-    eventListener.requestBodyStart(call)
+    call.eventListener.requestBodyStart(call)
    val rawRequestBody = codec.createRequestBody(request, contentLength)
    return RequestBodySink(
      delegate = rawRequestBody,
@@ -90,7 +89,7 @@ class Exchange(
    try {
      codec.flushRequest()
    } catch (e: IOException) {
-      eventListener.requestFailed(call, e)
+      call.eventListener.requestFailed(call, e)
      trackFailure(e)
      throw e
    }
@@ -101,14 +100,14 @@ class Exchange(
    try {
      codec.finishRequest()
    } catch (e: IOException) {
-      eventListener.requestFailed(call, e)
+      call.eventListener.requestFailed(call, e)
      trackFailure(e)
      throw e
    }
  }

  fun responseHeadersStart() {
-    eventListener.responseHeadersStart(call)
+    call.eventListener.responseHeadersStart(call)
  }

  @Throws(IOException::class)
@@ -118,14 +117,14 @@ class Exchange(
      result?.initExchange(this)
      return result
    } catch (e: IOException) {
-      eventListener.responseFailed(call, e)
+      call.eventListener.responseFailed(call, e)
      trackFailure(e)
      throw e
    }
  }

  fun responseHeadersEnd(response: Response) {
-    eventListener.responseHeadersEnd(call, response)
+    call.eventListener.responseHeadersEnd(call, response)
  }

  @Throws(IOException::class)
@@ -142,7 +141,7 @@ class Exchange(
        )
      return RealResponseBody(contentType, contentLength, source.buffer())
    } catch (e: IOException) {
-      eventListener.responseFailed(call, e)
+      call.eventListener.responseFailed(call, e)
      trackFailure(e)
      throw e
    }
@@ -217,16 +216,16 @@ class Exchange(
    }
    if (requestDone) {
      if (e != null) {
-        eventListener.requestFailed(call, e)
+        call.eventListener.requestFailed(call, e)
      } else {
-        eventListener.requestBodyEnd(call, bytesRead)
+        call.eventListener.requestBodyEnd(call, bytesRead)
      }
    }
    if (responseDone) {
      if (e != null) {
-        eventListener.responseFailed(call, e)
+        call.eventListener.responseFailed(call, e)
      } else {
-        eventListener.responseBodyEnd(call, bytesRead)
+        call.eventListener.responseBodyEnd(call, bytesRead)
      }
    }
    return call.messageDone(
@@ -273,7 +272,7 @@ class Exchange(
      try {
        if (invokeStartEvent) {
          invokeStartEvent = false
-          eventListener.requestBodyStart(call)
+          call.eventListener.requestBodyStart(call)
        }
        super.write(source, byteCount)
        this.bytesReceived += byteCount
@@ -347,7 +346,7 @@ class Exchange(

        if (invokeStartEvent) {
          invokeStartEvent = false
-          eventListener.responseBodyStart(call)
+          call.eventListener.responseBodyStart(call)
        }

        if (read == -1L) {
@@ -390,7 +389,7 @@ class Exchange(
      // If the body is closed without reading any bytes send a responseBodyStart() now.
      if (e == null && invokeStartEvent) {
        invokeStartEvent = false
-        eventListener.responseBodyStart(call)
+        call.eventListener.responseBodyStart(call)
      }
      return bodyComplete(
        bytesRead = bytesReceived,
--- a/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/RealCall.kt
+++ b/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/RealCall.kt
@@ -26,6 +26,7 @@ import java.util.concurrent.TimeUnit.MILLISECONDS
 import java.util.concurrent.atomic.AtomicBoolean
 import java.util.concurrent.atomic.AtomicInteger
 import java.util.concurrent.atomic.AtomicReference
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater
 import kotlin.reflect.KClass
 import okhttp3.Call
 import okhttp3.Callback
@@ -70,7 +71,8 @@ class RealCall(
  Lockable {
  private val connectionPool: RealConnectionPool = client.connectionPool.delegate

-  internal val eventListener: EventListener = client.eventListenerFactory.create(this)
+  @Volatile
+  internal var eventListener: EventListener = client.eventListenerFactory.create(this)

  private val timeout =
    object : AsyncTimeout() {
@@ -126,6 +128,13 @@ class RealCall(

  override fun timeout(): Timeout = timeout

+  override fun addEventListener(eventListener: EventListener) {
+    // Atomically replace the current eventListener with a composite one.
+    do {
+      val previous = this.eventListener
+    } while (!eventListenerUpdater.compareAndSet(this, previous, previous + eventListener))
+  }
+
  override fun <T : Any> tag(type: KClass<T>): T? = type.java.cast(tags.get()[type])

  override fun <T> tag(type: Class<out T>): T? = tag(type.kotlin)
@@ -202,7 +211,7 @@ class RealCall(
    interceptors += client.interceptors
    interceptors += RetryAndFollowUpInterceptor(client)
    interceptors += BridgeInterceptor(client.cookieJar)
-    interceptors += CacheInterceptor(client.cache)
+    interceptors += CacheInterceptor(this, client.cache)
    interceptors += ConnectInterceptor
    if (!forWebSocket) {
      interceptors += client.networkInterceptors
@@ -297,7 +306,7 @@ class RealCall(
    val exchangeFinder = this.exchangeFinder!!
    val connection = exchangeFinder.find()
    val codec = connection.newCodec(client, chain)
-    val result = Exchange(this, eventListener, exchangeFinder, codec)
+    val result = Exchange(this, exchangeFinder, codec)
    this.interceptorScopedExchange = result
    this.exchange = result
    withLock {
@@ -608,4 +617,13 @@ class RealCall(
     */
    val callStackTrace: Any?,
  ) : WeakReference<RealCall>(referent)
+
+  private companion object {
+    val eventListenerUpdater: AtomicReferenceFieldUpdater<RealCall, EventListener> =
+      AtomicReferenceFieldUpdater.newUpdater(
+        RealCall::class.java,
+        EventListener::class.java,
+        "eventListener",
+      )
+  }
 }
--- a/okhttp/src/jvmTest/kotlin/okhttp3/EventListenerTest.kt
+++ b/okhttp/src/jvmTest/kotlin/okhttp3/EventListenerTest.kt
@@ -15,6 +15,7 @@
 */
 package okhttp3

+import app.cash.burst.Burst
 import assertk.all
 import assertk.assertThat
 import assertk.assertions.contains
@@ -25,6 +26,7 @@ import assertk.assertions.isEqualTo
 import assertk.assertions.isFalse
 import assertk.assertions.isIn
 import assertk.assertions.isInstanceOf
+import assertk.assertions.isNotEmpty
 import assertk.assertions.isNotNull
 import assertk.assertions.isNull
 import assertk.assertions.isSameAs
@@ -95,6 +97,7 @@ import org.hamcrest.Description
 import org.hamcrest.Matcher
 import org.hamcrest.MatcherAssert
 import org.junit.Assume.assumeThat
+import org.junit.Assume.assumeTrue
 import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Tag
@@ -105,7 +108,10 @@ import org.junit.jupiter.api.extension.RegisterExtension
@Flaky // STDOUT logging enabled for test
@Timeout(30)
@Tag("Slow")
-class EventListenerTest {
+@Burst
+class EventListenerTest(
+  val listenerInstalledOn: ListenerInstalledOn = ListenerInstalledOn.Client,
+) {
  @RegisterExtension
  val platform = PlatformRule()

@@ -120,8 +126,11 @@ class EventListenerTest {
  private var client =
    clientTestRule
      .newClientBuilder()
-      .eventListenerFactory(clientTestRule.wrap(eventRecorder))
-      .build()
+      .apply {
+        if (listenerInstalledOn == ListenerInstalledOn.Client) {
+          eventListenerFactory(clientTestRule.wrap(eventRecorder))
+        }
+      }.build()
  private var socksProxy: SocksProxy? = null
  private var cache: Cache? = null

@@ -151,7 +160,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -192,7 +201,7 @@ class EventListenerTest {
    )
    val ipAddress = InetAddress.getLoopbackAddress().hostAddress
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(
@@ -235,7 +244,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -296,7 +305,7 @@ class EventListenerTest {
        .readTimeout(Duration.ofMillis(250))
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -345,7 +354,7 @@ class EventListenerTest {
        .readTimeout(Duration.ofMillis(250))
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -383,7 +392,7 @@ class EventListenerTest {
  @Test
  fun canceledCallEventSequence() {
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -411,7 +420,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -446,7 +455,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -462,7 +471,7 @@ class EventListenerTest {
    emptyBody: Boolean = false,
  ) {
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -520,7 +529,7 @@ class EventListenerTest {
    server.enqueue(MockResponse())
    server.enqueue(MockResponse())
    client
-      .newCall(
+      .newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -529,7 +538,7 @@ class EventListenerTest {
      .close()
    eventRecorder.removeUpToEvent<CallEnd>()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -703,7 +712,7 @@ class EventListenerTest {
  fun successfulDnsLookup() {
    server.enqueue(MockResponse())
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -728,7 +737,7 @@ class EventListenerTest {

    // Seed the pool.
    val call1 =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -739,7 +748,7 @@ class EventListenerTest {
    response1.body.close()
    eventRecorder.clearAllEvents()
    val call2 =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -772,7 +781,7 @@ class EventListenerTest {
        .dns(dns)
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url("http://fakeurl:" + server.port)
@@ -795,7 +804,7 @@ class EventListenerTest {
        .dns(FakeDns())
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url("http://fakeurl/")
@@ -819,7 +828,7 @@ class EventListenerTest {
        .dns(emptyDns)
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url("http://fakeurl/")
@@ -840,7 +849,7 @@ class EventListenerTest {
  fun successfulConnect() {
    server.enqueue(MockResponse())
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -855,7 +864,7 @@ class EventListenerTest {
    assertThat(connectStart.call).isSameAs(call)
    assertThat(connectStart.inetSocketAddress).isEqualTo(expectedAddress)
    assertThat(connectStart.proxy).isEqualTo(Proxy.NO_PROXY)
-    val connectEnd = eventRecorder.removeUpToEvent<ConnectEnd>()
+    val connectEnd = eventRecorder.removeUpToEvent<CallEvent.ConnectEnd>()
    assertThat(connectEnd.call).isSameAs(call)
    assertThat(connectEnd.inetSocketAddress).isEqualTo(expectedAddress)
    assertThat(connectEnd.protocol).isEqualTo(Protocol.HTTP_1_1)
@@ -871,7 +880,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -909,7 +918,7 @@ class EventListenerTest {
        .dns(DoubleInetAddressDns())
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -933,7 +942,7 @@ class EventListenerTest {
        .proxy(server.proxyAddress)
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url("http://www.fakeurl")
@@ -969,7 +978,7 @@ class EventListenerTest {
        .proxy(proxy)
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url("http://" + SocksProxy.HOSTNAME_THAT_ONLY_THE_PROXY_KNOWS + ":" + server.port)
@@ -1019,7 +1028,7 @@ class EventListenerTest {
        .proxyAuthenticator(RecordingOkAuthenticator("password", "Basic"))
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1040,7 +1049,7 @@ class EventListenerTest {
    enableTlsWithTunnel()
    server.enqueue(MockResponse())
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1066,7 +1075,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1098,7 +1107,7 @@ class EventListenerTest {
        .proxy(server.proxyAddress)
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1130,7 +1139,7 @@ class EventListenerTest {
        .dns(DoubleInetAddressDns())
        .build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1158,7 +1167,7 @@ class EventListenerTest {

    // Seed the pool.
    val call1 =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1169,7 +1178,7 @@ class EventListenerTest {
    response1.body.close()
    eventRecorder.clearAllEvents()
    val call2 =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1187,7 +1196,7 @@ class EventListenerTest {
  fun successfulConnectionFound() {
    server.enqueue(MockResponse())
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1217,7 +1226,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1237,7 +1246,7 @@ class EventListenerTest {

    // Seed the pool.
    val call1 =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1249,7 +1258,7 @@ class EventListenerTest {
    val connectionAcquired1 = eventRecorder.removeUpToEvent<ConnectionAcquired>()
    eventRecorder.clearAllEvents()
    val call2 =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1281,7 +1290,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1324,7 +1333,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1354,7 +1363,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1393,7 +1402,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1433,7 +1442,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1491,7 +1500,7 @@ class EventListenerTest {
    )
    val request = NonCompletingRequestBody()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1564,7 +1573,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1665,7 +1674,7 @@ class EventListenerTest {
            .setLevel(HttpLoggingInterceptor.Level.BODY),
        ).build()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1709,7 +1718,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1761,7 +1770,7 @@ class EventListenerTest {
    // Warm up the client so the timing part of the test gets a pooled connection.
    server.enqueue(MockResponse())
    val warmUpCall =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1796,7 +1805,7 @@ class EventListenerTest {

    // Create a request body with artificial delays.
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -1868,7 +1877,7 @@ class EventListenerTest {
        .build(),
    )
    server.enqueue(MockResponse())
-    val call = client.newCall(Request.Builder().url(server.url("/")).build())
+    val call = client.newCallWithListener(Request.Builder().url(server.url("/")).build())
    call.execute()
    assertThat(eventRecorder.recordedEventTypes()).containsExactly(
      CallStart::class,
@@ -1913,7 +1922,7 @@ class EventListenerTest {
        .build(),
    )
    otherServer.enqueue(MockResponse())
-    val call = client.newCall(Request.Builder().url(server.url("/")).build())
+    val call = client.newCallWithListener(Request.Builder().url(server.url("/")).build())
    call.execute()
    assertThat(eventRecorder.recordedEventTypes()).containsExactly(
      CallStart::class,
@@ -1970,7 +1979,7 @@ class EventListenerTest {
            chain.proceed(chain.request())
          },
        ).build()
-    val call = client.newCall(Request.Builder().url(server.url("/")).build())
+    val call = client.newCallWithListener(Request.Builder().url(server.url("/")).build())
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("b")
    assertThat(eventRecorder.recordedEventTypes()).containsExactly(
@@ -2020,7 +2029,7 @@ class EventListenerTest {
              .build()
          },
        ).build()
-    val call = client.newCall(Request.Builder().url(server.url("/")).build())
+    val call = client.newCallWithListener(Request.Builder().url(server.url("/")).build())
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("a")
    assertThat(eventRecorder.recordedEventTypes())
@@ -2043,7 +2052,7 @@ class EventListenerTest {
        .header("Expect", "100-continue")
        .post("abc".toRequestBody("text/plain".toMediaType()))
        .build()
-    val call = client.newCall(request)
+    val call = client.newCallWithListener(request)
    call.execute()
    assertThat(eventRecorder.recordedEventTypes()).containsExactly(
      CallStart::class,
@@ -2085,7 +2094,7 @@ class EventListenerTest {
        .header("Expect", "100-continue")
        .post("abc".toRequestBody("text/plain".toMediaType()))
        .build()
-    val call = client.newCall(request)
+    val call = client.newCallWithListener(request)
    call
      .execute()
      .use { response -> assertThat(response.body.string()).isEqualTo("") }
@@ -2105,7 +2114,7 @@ class EventListenerTest {
        .build(),
    )
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -2154,7 +2163,7 @@ class EventListenerTest {
        .build(),
    )
    var call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -2164,7 +2173,7 @@ class EventListenerTest {
    assertThat(response.code).isEqualTo(200)
    response.close()
    eventRecorder.clearAllEvents()
-    call = call.clone()
+    call = call.cloneWithListener()
    response = call.execute()
    assertThat(response.code).isEqualTo(200)
    assertThat(response.body.string()).isEqualTo("abc")
@@ -2205,7 +2214,7 @@ class EventListenerTest {
        .build(),
    )
    var call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -2215,7 +2224,7 @@ class EventListenerTest {
    assertThat(response.code).isEqualTo(200)
    response.close()
    eventRecorder.clearAllEvents()
-    call = call.clone()
+    call = call.cloneWithListener()
    response = call.execute()
    assertThat(response.code).isEqualTo(200)
    assertThat(response.body.string()).isEqualTo("abd")
@@ -2241,7 +2250,7 @@ class EventListenerTest {
  fun satisfactionFailure() {
    enableCache()
    val call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -2274,7 +2283,7 @@ class EventListenerTest {
        .build(),
    )
    var call =
-      client.newCall(
+      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
@@ -2285,7 +2294,7 @@ class EventListenerTest {
    assertThat(response.body.string()).isEqualTo("abc")
    response.close()
    eventRecorder.clearAllEvents()
-    call = call.clone()
+    call = call.cloneWithListener()
    response = call.execute()
    assertThat(response.code).isEqualTo(200)
    assertThat(response.body.string()).isEqualTo("abc")
@@ -2374,6 +2383,60 @@ class EventListenerTest {
    }
  }

+  /** Listeners added with [Call.addEventListener] don't exist on clones of that call. */
+  @Test
+  fun clonedCallDoesNotHaveAddedEventListeners() {
+    assumeTrue(listenerInstalledOn != ListenerInstalledOn.Client)
+
+    server.enqueue(
+      MockResponse
+        .Builder()
+        .body("abc")
+        .build(),
+    )
+    val call =
+      client.newCallWithListener(
+        Request
+          .Builder()
+          .url(server.url("/"))
+          .build(),
+      )
+    val clone = call.clone() // Not cloneWithListener.
+
+    val response = clone.execute()
+    assertThat(response.code).isEqualTo(200)
+    assertThat(response.body.string()).isEqualTo("abc")
+    response.body.close()
+    assertThat(eventRecorder.recordedEventTypes()).isEmpty()
+  }
+
+  /** Listeners added with [OkHttpClient.Builder.eventListener] are also added to clones. */
+  @Test
+  fun clonedCallHasClientEventListeners() {
+    assumeTrue(listenerInstalledOn == ListenerInstalledOn.Client)
+
+    server.enqueue(
+      MockResponse
+        .Builder()
+        .body("abc")
+        .build(),
+    )
+    val call =
+      client.newCallWithListener(
+        Request
+          .Builder()
+          .url(server.url("/"))
+          .build(),
+      )
+    val clone = call.clone() // Not cloneWithListener().
+
+    val response = clone.execute()
+    assertThat(response.code).isEqualTo(200)
+    assertThat(response.body.string()).isEqualTo("abc")
+    response.body.close()
+    assertThat(eventRecorder.recordedEventTypes()).isNotEmpty()
+  }
+
  /**
   * Returns a map with sample values for each possible parameter of an [EventListener] function
   * parameter.
@@ -2433,6 +2496,38 @@ class EventListenerTest {
    return Cache(cacheDir, (1024 * 1024).toLong())
  }

+  private fun OkHttpClient.newCallWithListener(request: Request): Call =
+    newCall(request)
+      .apply {
+        addEventRecorder(eventRecorder)
+      }
+
+  private fun Call.cloneWithListener(): Call =
+    clone()
+      .apply {
+        addEventRecorder(eventRecorder)
+      }
+
+  private fun Call.addEventRecorder(eventRecorder: EventRecorder) {
+    when (listenerInstalledOn) {
+      ListenerInstalledOn.Call -> {
+        addEventListener(eventRecorder.eventListener)
+      }
+
+      ListenerInstalledOn.Relay -> {
+        addEventListener(EventListenerRelay(this, eventRecorder).eventListener)
+      }
+
+      ListenerInstalledOn.Client -> {} // listener is added elsewhere.
+    }
+  }
+
+  enum class ListenerInstalledOn {
+    Client,
+    Call,
+    Relay,
+  }
+
  companion object {
    val anyResponse = CoreMatchers.any(Response::class.java)
  }
--- a/okhttp/src/jvmTest/kotlin/okhttp3/KotlinSourceModernTest.kt
+++ b/okhttp/src/jvmTest/kotlin/okhttp3/KotlinSourceModernTest.kt
@@ -202,6 +202,8 @@ class KotlinSourceModernTest {

        override fun timeout(): Timeout = TODO()

+        override fun addEventListener(eventListener: EventListener) = TODO()
+
        override fun <T : Any> tag(type: KClass<T>): T? = TODO()

        override fun <T> tag(type: Class<out T>): T? = TODO()