reader = null

      if (enqueuedClose && messageAndCloseQueue.isEmpty()) {
        // Close the writer on the writer's thread.
        val writerToClose = this.writer
        if (writerToClose != null) {
          this.writer = null
          taskQueue.execute("$name writer close", cancelable = false) {
            writerToClose.closeQuietly()
          }
        }