## Version 4.3.0

_2019-12-31_

 *  Fix: Degrade HTTP/2 connections after a timeout. When an HTTP/2 stream times out it may impact
    the stream only or the entire connection. With this fix OkHttp will now send HTTP/2 pings after
    a stream timeout to determine whether the connection should remain eligible for pooling.

 *  Fix: Don't call `EventListener.responseHeadersStart()` or `responseBodyStart()` until bytes have

  // These properties are only accessed by the thread executing the call.

  /** Initialized in [callStart]. */
  private var callStackTrace: Any? = null

  /** Finds an exchange to send the next request and receive the next response. */
  private var exchangeFinder: ExchangeFinder? = null

  var connection: RealConnection? = null
    private set
  private var timeoutEarlyExit = false

  /**

          return tunnelResult
        }
      }

      if (route.address.sslSocketFactory != null) {
        // Assume the server won't send a TLS ServerHello until we send a TLS ClientHello. If
        // that happens, then we will have buffered bytes that are needed by the SSLSocket!
        // This check is imperfect: it doesn't tell us whether a handshake will succeed, just

    @JvmField val TLS_RSA_WITH_SEED_CBC_SHA = init("TLS_RSA_WITH_SEED_CBC_SHA", 0x0096)

    // @JvmField val TLS_DH_DSS_WITH_SEED_CBC_SHA = init("TLS_DH_DSS_WITH_SEED_CBC_SHA", 0x0097)
    // @JvmField val TLS_DH_RSA_WITH_SEED_CBC_SHA = init("TLS_DH_RSA_WITH_SEED_CBC_SHA", 0x0098)
    // @JvmField val TLS_DHE_DSS_WITH_SEED_CBC_SHA = init("TLS_DHE_DSS_WITH_SEED_CBC_SHA", 0x0099)

import okio.BufferedSource
import okio.ForwardingTimeout
import okio.Sink
import okio.Source
import okio.Timeout

/**
 * A socket connection that can be used to send HTTP/1.1 messages. This class strictly enforces the
 * following lifecycle:
 *
 *  1. [Send request headers][writeRequest].
 *  2. Open a sink to write the request body. Either [known][newKnownLengthSink] or
 *     [chunked][newChunkedSink].

 *    cache.
 *
 * Sometimes a request will result in a conditional cache hit. If the cache contains a stale copy of
 * the response, the client will issue a conditional `GET`. The server will then send either
 * the updated response if it has changed, or a short 'not modified' response if the client's copy
 * is still valid. Such responses increment both the network count and hit count.
 *

    taskFaker.runTasks()
    client.listener.assertFailure(IOException::class.java, "source is closed")
    assertThat(client.webSocket!!.send("Hello!")).isFalse()
  }

  @Test
  fun socketClosedDuringMessageKillsWebSocket() {
    client2Server.source.close()
    assertThat(client.webSocket!!.send("Hello!")).isTrue()
    taskFaker.runTasks()
    client.listener.assertFailure(IOException::class.java, "source is closed")

    server.send(message3)
    clientListener.assertTextMessage(message3)

    // Empty client to server message.
    val message4 = ""
    client.send(message4)
    serverListener.assertTextMessage(message4)

    // Server to client message that shares context with message1.
    val message5 = message1 + message1
    server.send(message5)
    clientListener.assertTextMessage(message5)

  @Throws(IOException::class)
  fun connectionPreface() {
    this.withLock {
      if (closed) throw IOException("closed")
      if (!client) return // Nothing to write; servers don't send connection headers!
      if (logger.isLoggable(FINE)) {
        logger.fine(format(">> CONNECTION ${CONNECTION_PREFACE.hex()}"))
      }
      sink.write(CONNECTION_PREFACE)
      sink.flush()
    }
  }

import okio.Buffer
import okio.BufferedSource
import okio.ByteString
import okio.Source
import okio.Timeout

/**
 * Reads HTTP/2 transport frames.
 *
 * This implementation assumes we do not send an increased [frame][Settings.getMaxFrameSize] to the
 * peer. Hence, we expect all frames to have a max length of [Http2.INITIAL_MAX_FRAME_SIZE].
 */
class Http2Reader(