withLock {
      readBytes.update(total = read)
      val readBytesToAcknowledge = readBytes.unacknowledged
      if (readBytesToAcknowledge >= okHttpSettings.initialWindowSize / 2) {
        writeWindowUpdateLater(0, readBytesToAcknowledge)
        readBytes.update(acknowledged = readBytesToAcknowledge)
      }
      flowControlListener.receivingConnectionWindowChanged(readBytes)
    }
  }

  /**