Class ProcessHandler

shell/src/main/java/org/crsh/console/ProcessHandler.java:36–185

A process execution state machine. @author Julien Viet

 * @author Julien Viet
 */
class ProcessHandler extends Plugin implements ShellProcessContext {

  /**
   * A thread reading a line.
   */
  class Reader {
    final Thread thread;
    final Editor editor;
    final ArrayBlockingQueue<String> line;
    Reader(Thread thread, boolean echo) {
      this.thread = thread;
      this.editor = new Editor(console, echo);
      this.line = new ArrayBlockingQueue<String>(1);
    }
  }

  /** . */
  final Console console;

  /** . */
  final ShellProcess process;

  /** Weather or not a thread is reading a line callback. */
  final AtomicReference<Reader> editor;

  ProcessHandler(Console console, ShellProcess process) {
    this.console = console;
    this.process = process;
    this.editor = new AtomicReference<Reader>();
  }

  @Override
  public boolean takeAlternateBuffer() throws IOException {
    return console.driver.takeAlternateBuffer();
  }

  @Override
  public boolean releaseAlternateBuffer() throws IOException {
    return console.driver.releaseAlternateBuffer();
  }

  @Override
  public String getProperty(String propertyName) {
    return null;
  }

  @Override
  public String readLine(String msg, boolean echo) throws IOException, InterruptedException {
    Reader waiter = new Reader(Thread.currentThread(), echo);
    if (editor.compareAndSet(null, waiter)) {
      if (msg != null && msg.length() > 0) {
        console.driver.write(msg);
        console.driver.flush();
      }
      console.iterate();
      try {
        return waiter.line.take();
      } finally {