001: /* ====================================================================
002: * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
003: *
004: * Copyright (c) 1995-2002 Jcorporate Ltd. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * 1. Redistributions of source code must retain the above copyright
011: * notice, this list of conditions and the following disclaimer.
012: *
013: * 2. Redistributions in binary form must reproduce the above copyright
014: * notice, this list of conditions and the following disclaimer in
015: * the documentation and/or other materials provided with the
016: * distribution.
017: *
018: * 3. The end-user documentation included with the redistribution,
019: * if any, must include the following acknowledgment:
020: * "This product includes software developed by Jcorporate Ltd.
021: * (http://www.jcorporate.com/)."
022: * Alternately, this acknowledgment may appear in the software itself,
023: * if and wherever such third-party acknowledgments normally appear.
024: *
025: * 4. "Jcorporate" and product names such as "Expresso" must
026: * not be used to endorse or promote products derived from this
027: * software without prior written permission. For written permission,
028: * please contact info@jcorporate.com.
029: *
030: * 5. Products derived from this software may not be called "Expresso",
031: * or other Jcorporate product names; nor may "Expresso" or other
032: * Jcorporate product names appear in their name, without prior
033: * written permission of Jcorporate Ltd.
034: *
035: * 6. No product derived from this software may compete in the same
036: * market space, i.e. framework, without prior written permission
037: * of Jcorporate Ltd. For written permission, please contact
038: * partners@jcorporate.com.
039: *
040: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
041: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
042: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
043: * DISCLAIMED. IN NO EVENT SHALL JCORPORATE LTD OR ITS CONTRIBUTORS
044: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
045: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
046: * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
047: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
048: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
049: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
050: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
051: * SUCH DAMAGE.
052: * ====================================================================
053: *
054: * This software consists of voluntary contributions made by many
055: * individuals on behalf of the Jcorporate Ltd. Contributions back
056: * to the project(s) are encouraged when you make modifications.
057: * Please send them to support@jcorporate.com. For more information
058: * on Jcorporate Ltd. and its products, please see
059: * <http://www.jcorporate.com/>.
060: *
061: * Portions of this software are based upon other open source
062: * products and are subject to their respective licenses.
063: */
064:
065: package com.jcorporate.expresso.services.crontab;
066:
067: import com.jcorporate.expresso.core.registry.ExpressoThread;
068: import com.jcorporate.expresso.core.registry.MutableRequestRegistry;
069: import com.jcorporate.expresso.core.security.SuperUser;
070:
071: /**
072: * This class provides the thread for listening on various crontabs. It notifies
073: * the crontab when it's time to notify a listener.
074: *
075: * @author Mike Dubman
076: * @version 1.0
077: */
078: public class CronDaemon implements Runnable {
079:
080: protected Crontab mgr;
081: protected Thread thread;
082: private long sleepUntil = -1;
083: private boolean shutdown = false;
084:
085: public CronDaemon(Crontab mgr, boolean isDaemon, String waiterName) {
086: this .mgr = mgr;
087: thread = new ExpressoThread(this , waiterName);
088: thread.setDaemon(isDaemon);
089: thread.start();
090: }
091:
092: /**
093: * Updates the time it should sleep until
094: *
095: * @param sleepUntil absolute system time to sleep until
096: */
097: public synchronized void update(long sleepUntil) {
098: this .sleepUntil = sleepUntil;
099: notify();
100: }
101:
102: /**
103: * Restarts the cron daemon
104: *
105: * @param sleepUntil the absolute time to sleep until
106: */
107: public synchronized void restart(long sleepUntil) {
108: this .sleepUntil = sleepUntil;
109: notify();
110: }
111:
112: /**
113: * Stops the thread
114: */
115: public synchronized void stop() {
116: shutdown = true;
117: notify();
118: }
119:
120: public synchronized void run() {
121: //Set registry context.
122: new MutableRequestRegistry("default", SuperUser.SUPER_USER);
123:
124: while (!shutdown) {
125: try {
126:
127: // check if there's crontab entries here
128: if (sleepUntil <= 0) {
129:
130: // no crontab entry here. So wait for a new crontab entry to come along.
131: wait();
132: } else {
133:
134: // yes, there's an crontab entry here. Wait until the crontab entry is ready.
135: long timeout = sleepUntil
136: - System.currentTimeMillis();
137:
138: if (timeout > 0) {
139: wait(timeout);
140: }
141: }
142: // now that we've awakened again, check if an crontab entry is due (within
143: // 1 second)
144: if (sleepUntil >= 0
145: && (sleepUntil - System.currentTimeMillis() < 1000)) {
146:
147: // yes, an crontab entry is ready. Notify the listeners.
148: sleepUntil = -1;
149: mgr.notifyListeners();
150: }
151: } catch (InterruptedException e) {
152:
153: }
154: }
155: }
156: }
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