/* * Copyright (c) 2004, 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 { private static final boolean DEBUG = false; /** * 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; if (DEBUG) { System.err.println("computing timer delay: " + " oldInterval = " + oldInterval + " newInterval = " + newInterval + " samples = " + oldTask.executionCount() + " expired = " + expired); } /* * 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; } if (DEBUG) { System.err.println("rescheduling sampler task: interval = " + newInterval + " delay = " + delay); } timer.schedule(newTask, delay, newInterval); }}
/*
* Copyright (c) 2004, 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 {
private static final boolean DEBUG = false;
/**
* 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;
if (DEBUG) {
System.err.println("computing timer delay: "
+ " oldInterval = " + oldInterval
+ " newInterval = " + newInterval
+ " samples = " + oldTask.executionCount()
+ " expired = " + expired);
}
/*
* 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;
}
if (DEBUG) {
System.err.println("rescheduling sampler task: interval = "
+ newInterval
+ " delay = " + delay);
}
timer.schedule(newTask, delay, newInterval);
}
}