Prompt line rendering incorrectly on asynchronous writes.

[ghost]

I am trying to write to a console and read from it asynchronously using jline.console.ConsoleReader#print and jline.console.ConsoleReader#readLine methods.

Every write to the console is handlet by following instructions:

private void stashLine() {
    stashed = reader.getCursorBuffer().copy();
    try {
        reader.getOutput().write("\u001b[1G\u001b[K");
        reader.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }
}


private void unstashLine() {
    try {
        reader.resetPromptLine(reader.getPrompt(), stashed.toString(), stashed.cursor);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

@Override
protected void subAppend(E event) {
    if (this.isStarted()) {
        try {
            if (event instanceof DeferredProcessingAware) {
                ((DeferredProcessingAware) event).prepareForDeferredProcessing();
            }

            this.lock.lock();

            try {
                this.writeOut(event);
                if (reader != null) {
                    ByteArrayOutputStream stream = ((ByteArrayOutputStream) getOutputStream());
                    stream.flush();
                    stashLine();
                    reader.print(ConsoleReader.RESET_LINE + stream.toString(encoding) + Ansi.ansi().reset().toString());
                    unstashLine();
                    reader.drawLine();
                    reader.flush();
                    stream.reset();
                }
            } finally {
                this.lock.unlock();
            }
        } catch (IOException var6) {
            this.started = false;
            this.addStatus(new ErrorStatus("IO failure in appender", this, var6));
        }
    }
}

while every read from a console is handled in separate thread using:

public void start() {

    String command;

    try {
        while (Clockwork.getServer().isRunning() && (command = reader.readLine("> ")) != null) {
            logger.info("User input: {}", command);
        }
    } catch (IOException e) {
        logger.error("An exception occurred while processing console input.", e);
    }
}

I would like to achieve such begaviour that the prompt line is always located at the most bottom line of the console. This behaviour works as long as only one thread reads and writes to the console, however, whenever one thread is reading and another one tries to write to the console, the prompt line goes blank, even though I'm trying to reset it after writing (see methods like 'stashLine' and 'unstashLine' in provided source code).

I'm using Java 8 on Windows 7 alongside with JLine version 2.13. I've also tried JLine versions 2.7 and 2.12 where the same issue was reproduced.