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/*
* Copyright (c) 2008 Paul C. Buetow, vs@dev.buetow.org
*
* This program 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
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* All icons of the icons/ folder are under a Creative Commons
* Attribution-Noncommercial-Share Alike License a CC-by-nc-sa.
*
* The icon's homepage is http://code.google.com/p/ultimate-gnome/
*/
package protocols.implementations;
import java.util.ArrayList;
import java.util.Vector;
import protocols.VSAbstractProtocol;
import core.VSMessage;
/**
* The class VSOnePhaseCommitProtocol, an implementation of the one phase
* commit protocol.
*
* @author Paul C. Buetow
*/
public class VSOnePhaseCommitProtocol extends VSAbstractProtocol {
/** The serial version uid */
private static final long serialVersionUID = 1L;
/* Server variables */
private boolean ackSent;
/**
* Instantiates a one phase commit protocol.
*/
public VSOnePhaseCommitProtocol() {
super(VSAbstractProtocol.HAS_ON_SERVER_START);
setClassname(getClass().toString());
}
/* (non-Javadoc)
* @see events.VSAbstractProtocol#onServerInit()
*/
public void onServerInit() {
/* Can be changed via GUI variables editor of each process */
Vector<Integer> vec = new Vector<Integer>();
vec.add(1);
vec.add(3);
initVector("pids", vec, "PIDs beteiligter Prozesse");
initLong("timeout", 2500, "Zeit bis erneute Anfrage", "ms");
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onServerReset()
*/
public void onServerReset() {
if (pids != null) {
pids.clear();
pids.addAll(getVector("pids"));
}
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onServerStart()
*/
public void onServerStart() {
if (pids == null) {
pids = new ArrayList<Integer>();
pids.addAll(getVector("pids"));
}
if (pids.size() != 0) {
long timeout = getLong("timeout") + process.getTime();
/* Will run onServerSchedule() at the specified local time */
scheduleAt(timeout);
VSMessage message = new VSMessage();
message.setBoolean("wantAck", true);
sendMessage(message);
}
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onServerRecv(core.VSMessage)
*/
public void onServerRecv(VSMessage recvMessage) {
if (pids.size() == 0)
return;
if (recvMessage.getBoolean("isAck")) {
Integer pid = recvMessage.getIntegerObj("pid");
if (pids.contains(pid))
pids.remove(pid);
else
return;
log("ACK von Prozess " + pid + " erhalten!");
if (pids.size() == 0) {
log("ACKs von allen beteiligten Prozessen erhalten! " +
"Festgeschrieben!");
/* Remove the active schedule which has been created in the
onServerStart method */
removeSchedules();
}
}
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onServerSchedule()
*/
public void onServerSchedule() {
onServerStart();
}
/* Client variables, coordinator */
private ArrayList<Integer> pids;
/* (non-Javadoc)
* @see events.VSAbstractProtocol#onClientInit()
*/
public void onClientInit() {
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onClientReset()
*/
public void onClientReset() {
ackSent = false;
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onClientRecv(core.VSMessage)
*/
public void onClientRecv(VSMessage recvMessage) {
if (ackSent)
return;
VSMessage message = new VSMessage();
message.setBoolean("isAck", true);
message.setInteger("pid", process.getProcessID());
sendMessage(message);
ackSent = true;
log("Festgeschrieben");
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#onClientSchedule()
*/
public void onClientSchedule() {
}
/* (non-Javadoc)
* @see protocols.VSAbstractProtocol#toString()
*/
public String toString() {
return super.toString();
}
}
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