Class GenericTimer

server/src/main/java/com/linbit/timer/GenericTimer.java:23–370

Implements a timer that runs Actions at a predefined point in time or after a specified delay @param Type of the Action's unique identifier @param Type (e.g., subclass) of Action instances used by this timer @author Robert Altnoeder <robert.altnoeder@linbit.com>

 * @author Robert Altnoeder <robert.altnoeder@linbit.com>
 */
public class GenericTimer<K extends Comparable<K>, V extends Action<K>>
    implements Timer<K, V>, SystemService
{
    private static final ServiceName SERVICE_NAME;
    private static final String SERVICE_INFO = "Timed actions scheduler";

    // Maps interrupt time value to action id & action object
    private final TreeMap<Long, TreeMap<K, V>> timerMap;

    // Maps action id to interrupt time value
    private final TreeMap<K, Long> actionMap;

    private boolean stopFlag = false;

    private long schedWakeupTime = 0;

    private @Nullable ActionScheduler<K, V> sched;

    private ServiceName serviceInstanceName;

    static
    {
        try
        {
            SERVICE_NAME = new ServiceName("TimerEventService");
        }
        catch (InvalidNameException nameExc)
        {
            throw new ImplementationError(
                String.format(
                    "%s class contains an invalid name constant",
                    GenericTimer.class.getName()
                ),
                nameExc
            );
        }
    }

    /**
     * Constructs a new timer instance
     */
    public GenericTimer()
    {
        timerMap = new TreeMap<>();
        actionMap = new TreeMap<>();
        sched = null;
        serviceInstanceName = SERVICE_NAME;
    }

    /**
     * Adds an action to perform after a delay
     *
     * Note that actions are performed asynchronously and that a newly added action may
     * be performed before this method returns.
     *
     * Actions with a delay of zero are performed immediately in the context of the thread that called
     * the addDelayedAction() method.
     *