![Events Diagram](../assets/images/******@****.***)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java
class PrintingEventListener extends EventListener {
  private long callStartNanos;

    calls and that can receive data faster than they can process it. Previously, OkHttp limited
    HTTP/2 to 16 MiB of unacknowledged data per connection. With this fix there is a limit of 16 MiB
    of unacknowledged data per stream and no per-connection limit.

 *  Fix: Don't operate on a connection after it's been returned to the pool. This race occurred
    on failed web socket connection attempts.

    // client has received the response.
    Thread.sleep(500)
    val response2 = getResponse(newRequest("/b"))
    response1.body.source().timeout().timeout(100, TimeUnit.MILLISECONDS)
    assertContent("This comes after a busted connection", response2)

    // Check that a fresh connection was created, either immediately or after attempting reuse.

If you, however, don't use R8 you have to apply the rules from [this file][okhttp3_pro]. You might
also need rules from [Okio][okio] which is a dependency of this library.

 [okhttp3_pro]: https://raw.githubusercontent.com/square/okhttp/master/okhttp/src/main/resources/META-INF/proguard/okhttp3.pro

  font-size: 25px;
  line-height: 40px;
  padding: 3px 10px;
  display: inline-block;
  border-radius: 6px;
  color: #f0f0f0;
  margin: 5px 0;
  width: auto;
}

.logo {
  text-align: center;
  margin-top: 150px;

     * found, the existing values are replaced.
     */
    operator fun set(
      name: String,
      value: String,
    ) = commonSet(name, value)

    /** Equivalent to `build().get(name)`, but potentially faster. */
    operator fun get(name: String): String? = commonGet(name)

    fun build(): Headers = commonBuild()
  }

  companion object {
    /**

        this.maxIntermediateCas = maxIntermediateCas
      }

    /**
     * Configure the certificate to generate a 256-bit ECDSA key, which provides about 128 bits of
     * security. ECDSA keys are noticeably faster than RSA keys.
     *
     * This is the default configuration and has been since this API was introduced in OkHttp
     * 3.11.0. Note that the default may change in future releases.
     */
    fun ecdsa256() =

 * [sslengine]: https://developer.android.com/reference/javax/net/ssl/SSLEngine.html
 * [oracle_providers]: https://docs.oracle.com/javase/10/security/oracle-providers.htm
 * [conscrypt_providers]: https://github.com/google/conscrypt/blob/master/common/src/main/java/org/conscrypt/NativeCrypto.java
 */
class CipherSuite private constructor(
  /**
   * Returns the Java name of this cipher suite. For some older cipher suites the Java name has the

  value: String,
) = apply {
  headersCheckName(name)
  headersCheckValue(value, name)
  removeAll(name)
  commonAddLenient(name, value)
}

/** Equivalent to `build().get(name)`, but potentially faster. */
internal fun Headers.Builder.commonGet(name: String): String? {
  for (i in namesAndValues.size - 2 downTo 0 step 2) {
    if (name.equals(namesAndValues[i], ignoreCase = true)) {
      return namesAndValues[i + 1]

URLs that share the same address may also share the same underlying TCP socket connection. Sharing a connection has substantial performance benefits: lower latency, higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-pool/) that automatically reuses HTTP/1.x connections and multiplexes HTTP/2 connections.