// Scala source: ./examples/Reference.scala
import concurrency;
class Reference[a](x: a) with {
  val monitor$0 = new scala.Monitor;
  var status$0 = 0;
  val value$queue = new join.Queue[(scala.Unit, join.SyncVar[a])];
  val update$queue = new join.Queue[(a, join.SyncVar[Unit])];
  val state$queue = new join.Queue[a];
  def rule$0(param$0: scala.Unit, value$cont: join.SyncVar[a], x: a): scala.Unit = spawn.$less(value$cont.set(x)).$bar(state(x)).$greater;
  def rule$1(x: a, update$cont: join.SyncVar[Unit], y: a): scala.Unit = spawn.$less(update$cont.set(())).$bar(state(x)).$greater;
  def value: a = {
    val value$cont = new join.SyncVar[a];
    monitor$0.synchronized(if (status$0.$amp(1).$bang$eq(0))
        value$queue.put(((), value$cont))
      else
         status$0.match({
            case 4 => {
              val arg$0 = state$queue.get;
              if (state$queue.isEmpty)
                status$0 = status$0.$minus(4)
              ;
              scala.Predef.fork(rule$0((), value$cont, arg$0));
              ()
            }
            case _ => {
              status$0 = status$0.$plus(1);
              value$queue.put(((), value$cont))
            }
          }));
    value$cont.get
  };
  def update(x: a): Unit = {
    val update$cont = new join.SyncVar[Unit];
    monitor$0.synchronized(if (status$0.$amp(2).$bang$eq(0))
        update$queue.put((x, update$cont))
      else
         status$0.match({
            case 4 => {
              val arg$1 = state$queue.get;
              if (state$queue.isEmpty)
                status$0 = status$0.$minus(4)
              ;
              scala.Predef.fork(rule$1(x, update$cont, arg$1));
              ()
            }
            case _ => {
              status$0 = status$0.$plus(2);
              update$queue.put((x, update$cont))
            }
          }));
    update$cont.get
  };
  private def state(x: a): scala.Unit = monitor$0.synchronized(if (status$0.$amp(4).$bang$eq(0))
      state$queue.put(x)
    else
       status$0.match({
          case 1 => {
            val (arg$2, arg$3) = value$queue.get;
            if (value$queue.isEmpty)
              status$0 = status$0.$minus(1)
            ;
            scala.Predef.fork(rule$0(arg$2, arg$3, x));
            ()
          }
          case 2 => {
            val (arg$4, arg$5) = update$queue.get;
            if (update$queue.isEmpty)
              status$0 = status$0.$minus(2)
            ;
            scala.Predef.fork(rule$1(arg$4, arg$5, x));
            ()
          }
          case 3 => {
            val (arg$6, arg$7) = value$queue.get;
            if (value$queue.isEmpty)
              status$0 = status$0.$minus(1)
            ;
            scala.Predef.fork(rule$0(arg$6, arg$7, x));
            ()
          }
          case _ => {
            status$0 = status$0.$plus(4);
            state$queue.put(x)
          }
        }));
  ();
  state(x)
};
module refTest with {
  def main(args: Array[String]): Unit = {
    val v = new Reference(5);
    System.out.println("value = ".$plus(v.value));
    v.update(42);
    System.out.println("value = ".$plus(v.value));
    System.out.println("value = ".$plus(v.value));
    v.update(23);
    System.out.println("value = ".$plus(v.value));
    System.out.println("value = ".$plus(v.value))
  }
};