Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.wake.time;
020
021
022import org.apache.reef.tang.annotations.DefaultImplementation;
023import org.apache.reef.tang.annotations.Name;
024import org.apache.reef.tang.annotations.NamedParameter;
025import org.apache.reef.wake.EventHandler;
026import org.apache.reef.wake.impl.LoggingEventHandler;
027import org.apache.reef.wake.impl.MissingStartHandlerHandler;
028import org.apache.reef.wake.time.event.Alarm;
029import org.apache.reef.wake.time.event.StartTime;
030import org.apache.reef.wake.time.event.StopTime;
031import org.apache.reef.wake.time.runtime.RuntimeClock;
032import org.apache.reef.wake.time.runtime.event.IdleClock;
033import org.apache.reef.wake.time.runtime.event.RuntimeStart;
034import org.apache.reef.wake.time.runtime.event.RuntimeStop;
035
036import java.util.Set;
037
038/**
039 * Represents a clock.
040 */
041@DefaultImplementation(RuntimeClock.class)
042public interface Clock extends Runnable, AutoCloseable {
043
044  /**
045   * Schedule a TimerEvent at the given future offset.
046   *
047   * @param handler to be called
048   * @param offset  into the future
049   * @throws IllegalStateException when the clock has been already closed
050   */
051  void scheduleAlarm(final int offset, final EventHandler<Alarm> handler);
052
053  /**
054   * This will stop the clock after all client alarms
055   * finish executing.
056   */
057  @Override
058  void close();
059
060  /**
061   * This stops the clock immediately, without waiting for
062   * client alarms to finish.
063   */
064  void stop();
065
066  /**
067   * This stops the clock immediately, without waiting for
068   * client alarms to finish. Stops with an exception that
069   * is propagated to RuntimeStopHandlers.
070   */
071  void stop(final Throwable exception);
072
073  /**
074   * Clock is idle if it has no future Alarms set.
075   *
076   * @return true if idle, otherwise false
077   */
078  boolean isIdle();
079
080  /**
081   * Bind this to an event handler to statically subscribe to the StartTime Event.
082   */
083  @NamedParameter(default_class = MissingStartHandlerHandler.class, doc = "Will be called upon the start event")
084  class StartHandler implements Name<Set<EventHandler<StartTime>>> {
085  }
086
087  /**
088   * Bind this to an event handler to statically subscribe to the StopTime Event.
089   */
090  @NamedParameter(default_class = LoggingEventHandler.class, doc = "Will be called upon the stop event")
091  class StopHandler implements Name<Set<EventHandler<StopTime>>> {
092  }
093
094  /**
095   * Bind this to an event handler to statically subscribe to the RuntimeStart Event.
096   */
097  @NamedParameter(default_class = LoggingEventHandler.class, doc = "Will be called upon the runtime start event")
098  class RuntimeStartHandler implements Name<Set<EventHandler<RuntimeStart>>> {
099  }
100
101  /**
102   * Bind this to an event handler to statically subscribe to the RuntimeStart Event.
103   */
104  @NamedParameter(default_class = LoggingEventHandler.class, doc = "Will be called upon the runtime stop event")
105  class RuntimeStopHandler implements Name<Set<EventHandler<RuntimeStop>>> {
106  }
107
108  /**
109   * Bind this to an event handler to statically subscribe to the IdleClock Event.
110   */
111  @NamedParameter(default_class = LoggingEventHandler.class, doc = "Will be called upon the Idle event")
112  class IdleHandler implements Name<Set<EventHandler<IdleClock>>> {
113  }
114}