| /* |
| * Copyright (c) 2004, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.jvmstat.perfdata.monitor; |
| |
| import java.util.*; |
| |
| /** |
| * Utility methods for use with {@link CountedTimerTask} instances. |
| * |
| * @author Brian Doherty |
| * @since 1.5 |
| */ |
| public class CountedTimerTaskUtils { |
| |
| // 8028357 removed old, inefficient debug logging |
| |
| /** |
| * Reschedule a CountedTimeTask at a different interval. Probably not |
| * named correctly. This method cancels the old task and computes the |
| * delay for starting the new task based on the new interval and the |
| * time at which the old task was last executed. |
| * |
| * @param timer the Timer for the task |
| * @param oldTask the old Task |
| * @param newTask the new Task |
| * @param oldInterval the old interval; use for debugging output |
| * purposes only. |
| * @param newInterval scheduling interval in milliseconds |
| */ |
| public static void reschedule(Timer timer, CountedTimerTask oldTask, |
| CountedTimerTask newTask, int oldInterval, |
| int newInterval) { |
| |
| long now = System.currentTimeMillis(); |
| long lastRun = oldTask.scheduledExecutionTime(); |
| long expired = now - lastRun; |
| |
| /* |
| * check if original task ever ran - if not, then lastRun is |
| * undefined and we simply set the delay to 0. |
| */ |
| long delay = 0; |
| if (oldTask.executionCount() > 0) { |
| long remainder = newInterval - expired; |
| delay = remainder >= 0 ? remainder : 0; |
| } |
| |
| timer.schedule(newTask, delay, newInterval); |
| } |
| } |