* share the same [Address] may share a [Connection]. This class implements the policy
 * of which connections to keep open for future use.
 *
 * @constructor Create a new connection pool with tuning parameters appropriate for a single-user
 * application. The tuning parameters in this pool are subject to change in future OkHttp releases.
 * Currently this pool holds up to 5 idle connections which will be evicted after 5 minutes of
 * inactivity.
 */

) : ConnectionListener() {
  val eventSequence: Deque<ConnectionEvent> = ConcurrentLinkedDeque()

  private val forbiddenLocks = mutableSetOf<Any>()

  /** The timestamp of the last taken event, used to measure elapsed time between events. */
  private var lastTimestampNs: Long? = null

  /** Confirm that the thread does not hold a lock on `lock` during the callback. */
  fun forbidLock(lock: Any) {
    forbiddenLocks.add(lock)

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

### Availability

     * fail. Use a custom [HostnameVerifier] to ignore such problems.
     *
     * Other TLS features are still used but provide no security benefits in absence of the above
     * gaps. For example, an insecure TLS connection is capable of negotiating HTTP/2 with ALPN and
     * it also has a regular-looking handshake.
     *
     * **This feature is not supported on Android API levels less than 24.** Prior releases lacked

      )
    }

    client.routeDatabase.failed(failedRoute)
  }

  /**
   * Track a failure using this connection. This may prevent both the connection and its route from
   * being used for future exchanges.
   */
  override fun trackFailure(
    call: RealCall,
    e: IOException?,
  ) {
    var noNewExchangesEvent = false
    lock.withLock {
      if (e is StreamResetException) {

   * bodies may only be used with HTTP/2. Calls to HTTP/1 servers will fail before the HTTP request
   * is transmitted. If you cannot ensure that your client and server both support HTTP/2, do not
   * use this feature.
   *
   * ### Duplex APIs
   *
   * With regular request bodies it is not legal to write bytes to the sink passed to
   * [RequestBody.writeTo] after that method returns. For duplex requests bodies that condition is

Code Cleanup
------------

IntelliJ and Android Studio offer a **Code Cleanup** feature that will automatically update
deprecated APIs with their replacements. Access this feature from the _Search Anywhere_ dialog
(double-press shift) or under the _Analyze_ menu.

We’ve included deprecated APIs in OkHttp 4.0 because they make migration easy. We will remove them
in a future release! If you’re skipping releases, it’ll be much easier if you upgrade to OkHttp 4.0

 *  **Fix: Lazily initialize the response cache.** This avoids strict mode
    warnings when initializing OkHttp on Android‘s main thread.

 *  **Fix: Disable ALPN on Android 4.4.** That release of the feature was
    unstable and prone to native crashes in the underlying OpenSSL code.
 *  Fix: Don't send both `If-None-Match` and `If-Modified-Since` cache headers
    when both are applicable.

import java.net.InetSocketAddress
import java.net.ServerSocket
import java.security.PrivateKey
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors
import java.util.concurrent.Future
import javax.net.ServerSocketFactory
import javax.net.SocketFactory
import javax.net.ssl.SSLSocket
import okhttp3.Handshake
import okhttp3.Handshake.Companion.handshake
import okhttp3.TestUtil.threadFactory

   * currently-executing task unless it is also scheduled for future execution.
   */
  val scheduledTasks: List<Task>
    get() = taskRunner.lock.withLock { futureTasks.toList() }

  /**
   * Schedules [task] for execution in [delayNanos]. A task may only have one future execution
   * scheduled. If the task is already in the queue, the earliest execution time is used.
   *