var flushHeaders = flushHeaders
    this.withLock {
      this.hasResponseHeaders = true
      if (outFinished) {
        this.sink.finished = true
        condition.signalAll() // Because doReadTimeout() may have changed.
      }
    }

    // Only DATA frames are subject to flow-control. Transmit the HEADER frame if the connection
    // flow-control window is fully depleted.
    if (!flushHeaders) {
      this.withLock {