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8054834: Modular Source Code
Co-authored-by: Alan Bateman <alan.bateman@oracle.com> Co-authored-by: Alex Buckley <alex.buckley@oracle.com> Co-authored-by: Erik Joelsson <erik.joelsson@oracle.com> Co-authored-by: Jonathan Gibbons <jonathan.gibbons@oracle.com> Co-authored-by: Karen Kinnear <karen.kinnear@oracle.com> Co-authored-by: Magnus Ihse Bursie <magnus.ihse.bursie@oracle.com> Co-authored-by: Mandy Chung <mandy.chung@oracle.com> Co-authored-by: Mark Reinhold <mark.reinhold@oracle.com> Co-authored-by: Paul Sandoz <paul.sandoz@oracle.com> Reviewed-by: alanb, chegar, ihse, mduigou
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12567 changed files with 5941 additions and 5903 deletions
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jdk/src/java.base/share/classes/java/util/TimerTask.java
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jdk/src/java.base/share/classes/java/util/TimerTask.java
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/*
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* Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.util;
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/**
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* A task that can be scheduled for one-time or repeated execution by a Timer.
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*
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* @author Josh Bloch
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* @see Timer
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* @since 1.3
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*/
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public abstract class TimerTask implements Runnable {
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/**
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* This object is used to control access to the TimerTask internals.
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*/
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final Object lock = new Object();
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/**
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* The state of this task, chosen from the constants below.
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*/
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int state = VIRGIN;
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/**
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* This task has not yet been scheduled.
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*/
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static final int VIRGIN = 0;
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/**
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* This task is scheduled for execution. If it is a non-repeating task,
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* it has not yet been executed.
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*/
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static final int SCHEDULED = 1;
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/**
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* This non-repeating task has already executed (or is currently
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* executing) and has not been cancelled.
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*/
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static final int EXECUTED = 2;
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/**
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* This task has been cancelled (with a call to TimerTask.cancel).
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*/
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static final int CANCELLED = 3;
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/**
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* Next execution time for this task in the format returned by
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* System.currentTimeMillis, assuming this task is scheduled for execution.
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* For repeating tasks, this field is updated prior to each task execution.
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*/
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long nextExecutionTime;
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/**
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* Period in milliseconds for repeating tasks. A positive value indicates
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* fixed-rate execution. A negative value indicates fixed-delay execution.
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* A value of 0 indicates a non-repeating task.
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*/
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long period = 0;
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/**
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* Creates a new timer task.
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*/
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protected TimerTask() {
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}
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/**
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* The action to be performed by this timer task.
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*/
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public abstract void run();
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/**
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* Cancels this timer task. If the task has been scheduled for one-time
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* execution and has not yet run, or has not yet been scheduled, it will
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* never run. If the task has been scheduled for repeated execution, it
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* will never run again. (If the task is running when this call occurs,
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* the task will run to completion, but will never run again.)
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*
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* <p>Note that calling this method from within the <tt>run</tt> method of
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* a repeating timer task absolutely guarantees that the timer task will
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* not run again.
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*
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* <p>This method may be called repeatedly; the second and subsequent
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* calls have no effect.
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*
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* @return true if this task is scheduled for one-time execution and has
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* not yet run, or this task is scheduled for repeated execution.
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* Returns false if the task was scheduled for one-time execution
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* and has already run, or if the task was never scheduled, or if
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* the task was already cancelled. (Loosely speaking, this method
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* returns <tt>true</tt> if it prevents one or more scheduled
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* executions from taking place.)
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*/
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public boolean cancel() {
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synchronized(lock) {
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boolean result = (state == SCHEDULED);
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state = CANCELLED;
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return result;
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}
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}
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/**
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* Returns the <i>scheduled</i> execution time of the most recent
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* <i>actual</i> execution of this task. (If this method is invoked
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* while task execution is in progress, the return value is the scheduled
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* execution time of the ongoing task execution.)
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*
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* <p>This method is typically invoked from within a task's run method, to
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* determine whether the current execution of the task is sufficiently
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* timely to warrant performing the scheduled activity:
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* <pre>{@code
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* public void run() {
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* if (System.currentTimeMillis() - scheduledExecutionTime() >=
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* MAX_TARDINESS)
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* return; // Too late; skip this execution.
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* // Perform the task
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* }
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* }</pre>
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* This method is typically <i>not</i> used in conjunction with
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* <i>fixed-delay execution</i> repeating tasks, as their scheduled
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* execution times are allowed to drift over time, and so are not terribly
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* significant.
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*
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* @return the time at which the most recent execution of this task was
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* scheduled to occur, in the format returned by Date.getTime().
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* The return value is undefined if the task has yet to commence
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* its first execution.
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* @see Date#getTime()
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*/
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public long scheduledExecutionTime() {
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synchronized(lock) {
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return (period < 0 ? nextExecutionTime + period
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: nextExecutionTime - period);
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}
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}
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}
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