Clock.jr

import java.util.*;
import edu.ucdavis.jr.*;

public class Clock {

  public op MyTime getTime();
  public op void setAlarm(cap void() ch, MyTime t);
  public op void setAlarmEndTime(cap void() ch);
  public op void shutdown();

  private op void tick();

  private MyTime currentTime;
  private int ms;
  private Map<MyTime, Set<cap void()>> alarms = new HashMap<MyTime, Set<cap void()>>();
  public MyTime endTime;

  private op void stopTicker();

  public Clock(int ms, MyTime endTime) {
    currentTime = new MyTime(0, 0 ,0);
    this.ms = ms;
    this.endTime = endTime;
    alarms.put(endTime, new HashSet<cap void()>());
  }

  private process loop {
    boolean run = true;
    while (run) {
      inni void tick() {
        // Send current alarms
        Set<cap void()> chs = alarms.remove(currentTime);
        if (chs!=null)
          for(Object ch : chs)
          send ((cap void())ch)();
        // Increment time
        currentTime.increment();
      }
      [] MyTime getTime() {
        return ((MyTime)currentTime.clone());
      }
      [] void setAlarm(cap void() ch, MyTime t) {
        MyTime at = ((MyTime)currentTime.clone()).add(t);
        Set<cap void()> chs = alarms.remove(at);
        if (chs == null)
          chs = new HashSet<cap void()>();
        chs.add(ch);
        alarms.put(at, chs);
      }
      [] void setAlarmEndTime(cap void() ch) {
        Set<cap void()> chs = alarms.remove(endTime);
        if (chs == null)
          send ch();
        else {
          chs.add(ch);
          alarms.put(endTime, chs);
        }
      }
      [] void shutdown() {
        run = false;
      }
    }
    send stopTicker();
    if (alarms.size() > 0)
      System.err.println("Some alarms left: "+alarms);
  }

  private process ticker {
    boolean run = true;
    long next = System.currentTimeMillis();
    long w;
    do {
      inni void stopTicker() {
        run = false;
      }
      else {
        next += ms;
        w = Math.max(0,next-System.currentTimeMillis());
        edu.ucdavis.jr.JR.nap(w);
        send tick();
      }
      } while (run);
    }

  }