From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libjava/classpath/java/util/TimerTask.java | 145 +++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) create mode 100644 libjava/classpath/java/util/TimerTask.java (limited to 'libjava/classpath/java/util/TimerTask.java') diff --git a/libjava/classpath/java/util/TimerTask.java b/libjava/classpath/java/util/TimerTask.java new file mode 100644 index 000000000..b03118ad0 --- /dev/null +++ b/libjava/classpath/java/util/TimerTask.java @@ -0,0 +1,145 @@ +/* TimerTask.java -- Task that can be run at a later time if given to a Timer. + Copyright (C) 2000 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.util; + +/** + * Task that can be run at a later time if given to a Timer. + * The TimerTask must implement a run method that will be called by the + * Timer when the task is scheduled for execution. The task can check when + * it should have been scheduled and cancel itself when no longer needed. + *

+ * Example: + * 

+ *  Timer timer = new Timer();
+ *  TimerTask task = new TimerTask() {
+ *      public void run() {
+ *      if (this.scheduledExecutionTime() < System.currentTimeMillis() + 500)
+ *          // Do something
+ *      else
+ *          // Complain: We are more then half a second late!
+ *      if (someStopCondition)
+ *          this.cancel(); // This was our last execution
+ *  };
+ *  timer.scheduleAtFixedRate(task, 1000, 1000); // schedule every second
+ *
+ *

+ * Note that a TimerTask object is a one shot object and can only given once + * to a Timer. (The Timer will use the TimerTask object for bookkeeping, + * in this implementation). + *

+ * This class also implements Runnable to make it possible to + * give a TimerTask directly as a target to a Thread. + * + * @see Timer + * @since 1.3 + * @author Mark Wielaard (mark@klomp.org) + */ +public abstract class TimerTask implements Runnable +{ + /** + * If positive the next time this task should be run. + * If negative this TimerTask is canceled or executed for the last time. + */ + long scheduled; + + /** + * If positive the last time this task was run. + * If negative this TimerTask has not yet been scheduled. + */ + long lastExecutionTime; + + /** + * If positive the number of milliseconds between runs of this task. + * If -1 this task doesn't have to be run more then once. + */ + long period; + + /** + * If true the next time this task should be run is relative to + * the last scheduled time, otherwise it can drift in time. + */ + boolean fixed; + + /** + * Creates a TimerTask and marks it as not yet scheduled. + */ + protected TimerTask() + { + this.scheduled = 0; + this.lastExecutionTime = -1; + } + + /** + * Marks the task as canceled and prevents any further execution. + * Returns true if the task was scheduled for any execution in the future + * and this cancel operation prevents that execution from happening. + *

+ * A task that has been canceled can never be scheduled again. + *

+ * In this implementation the TimerTask it is possible that the Timer does + * keep a reference to the TimerTask until the first time the TimerTask + * is actually scheduled. But the reference will disappear immediatly when + * cancel is called from within the TimerTask run method. + */ + public boolean cancel() + { + boolean prevented_execution = (this.scheduled >= 0); + this.scheduled = -1; + return prevented_execution; + } + + /** + * Method that is called when this task is scheduled for execution. + */ + public abstract void run(); + + /** + * Returns the last time this task was scheduled or (when called by the + * task from the run method) the time the current execution of the task + * was scheduled. When the task has not yet run the return value is + * undefined. + *

+ * Can be used (when the task is scheduled at fixed rate) to see the + * difference between the requested schedule time and the actual time + * that can be found with System.currentTimeMillis(). + */ + public long scheduledExecutionTime() + { + return lastExecutionTime; + } +} -- cgit v1.2.3