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.examples.pool; 020 021import org.apache.reef.tang.annotations.Parameter; 022import org.apache.reef.task.Task; 023 024import javax.inject.Inject; 025import java.util.logging.Level; 026import java.util.logging.Logger; 027 028/** 029 * Sleep for delay seconds and quit. 030 */ 031public final class SleepTask implements Task { 032 033 /** 034 * Standard java logger. 035 */ 036 private static final Logger LOG = Logger.getLogger(SleepTask.class.getName()); 037 038 /** 039 * Number of milliseconds to sleep. 040 */ 041 private final int delay; 042 043 /** 044 * Task constructor. Parameters are injected automatically by TANG. 045 * 046 * @param delay number of seconds to sleep. 047 */ 048 @Inject 049 private SleepTask(@Parameter(Launch.Delay.class) final Integer delay) { 050 this.delay = delay * 1000; 051 } 052 053 /** 054 * Sleep for delay milliseconds and return. 055 * 056 * @param memento ignored. 057 * @return null. 058 */ 059 @Override 060 public byte[] call(final byte[] memento) { 061 LOG.log(Level.FINE, "Task started: sleep for: {0} msec.", this.delay); 062 final long ts = System.currentTimeMillis(); 063 for (long period = this.delay; period > 0; period -= System.currentTimeMillis() - ts) { 064 try { 065 Thread.sleep(period); 066 } catch (final InterruptedException ex) { 067 LOG.log(Level.FINEST, "Interrupted: {0}", ex); 068 } 069 } 070 LOG.log(Level.FINE, "Task finished after {0} msec.", System.currentTimeMillis() - ts); 071 return null; 072 } 073}