// Everything else wants a fresh connection.
            noNewExchangesEvent = !noNewExchanges
            noNewExchanges = true
            routeFailureCount++
          }
        }
      } else if (!isMultiplexed || e is ConnectionShutdownException) {
        noNewExchangesEvent = !noNewExchanges
        noNewExchanges = true

        // If this route hasn't completed a call, avoid it for new connections.

      if (connection.noNewExchanges) {
        assertThat(eventSequence).matchesPredicate { deque ->
          deque.any { it is NoNewExchanges && it.connection == connection }
        }
      }
    }

    logEvent(ConnectionEvent.ConnectionReleased(System.nanoTime(), connection, call))
  }

    return ChunkedSource(url)
  }

  private fun newUnknownLengthSource(): Source {
    check(state == STATE_OPEN_RESPONSE_BODY) { "state: $state" }
    state = STATE_READING_RESPONSE_BODY
    carrier.noNewExchanges()
    return UnknownLengthSource()
  }

  /**
   * Sets the delegate of `timeout` to [Timeout.NONE] and resets its underlying timeout

  }

  override fun connectionConnectionClosed(connection: RealConnection) {
    connection.connectionListener.connectionClosed(connection)
  }

  override fun noNewExchanges(connection: RealConnection) {
    connection.connectionListener.noNewExchanges(connection)
  }

  override fun doExtensiveHealthChecks(): Boolean {
    return chain.request.method != "GET"
  }

  override fun isCanceled(): Boolean {

    val toClose: Socket? =
      candidate.withLock {
        when {
          !healthy -> {
            noNewExchangesEvent = !candidate.noNewExchanges
            candidate.noNewExchanges = true
            connectionUser.releaseConnectionNoEvents()
          }
          candidate.noNewExchanges || !sameHostAndPort(candidate.route().address.url) -> {
            connectionUser.releaseConnectionNoEvents()
          }

          noNewExchangesEvent = !connection.noNewExchanges
          connection.noNewExchanges = true
          connectionUser.releaseConnectionNoEvents()
        }
      if (toClose != null) {
        toClose.closeQuietly()
        connectionListener.connectionClosed(connection)
      } else if (noNewExchangesEvent) {
        connectionListener.noNewExchanges(connection)
      }
    }
    return null
  }

   */
  open fun connectionReleased(
    connection: Connection,
    call: Call,
  ) {}

  /**
   * Invoked when a connection is marked for no new exchanges.
   */
  open fun noNewExchanges(connection: Connection) {}

  @ExperimentalOkHttpApi
  companion object {
    val NONE: ConnectionListener = object : ConnectionListener() {}
  }

    assertThat(server2.requestCount).isEqualTo(1)

    assertThat(clientTestRule.recordedConnectionEventTypes()).containsExactly(
      "ConnectStart",
      "ConnectEnd",
      "ConnectionAcquired",
      "NoNewExchanges",
      "ConnectionReleased",
      "ConnectionClosed",
      "ConnectStart",
      "ConnectEnd",
      "ConnectionAcquired",
      "ConnectionReleased",
    )
  }

  @Test

  fun connectionConnectionAcquired(connection: RealConnection)

  fun connectionConnectionReleased(connection: RealConnection)

  fun connectionConnectionClosed(connection: RealConnection)

  fun noNewExchanges(connection: RealConnection)

  fun doExtensiveHealthChecks(): Boolean

  fun isCanceled(): Boolean

  fun candidateConnection(): RealConnection?

  fun proxySelectStart(url: HttpUrl)

#### Per-Connection Locks

Each connection has its own lock. The connections in the pool are all in a `ConcurrentLinkedQueue`. Due to data races, iterators of this queue may return removed connections. Callers must check the connection's `noNewExchanges` property before using connections from the pool.

The connection lock is never held while doing I/O (even closing a socket) to prevent contention.