/**
* SAMOA - PROTOCOL FRAMEWORK
* Copyright (C) 2005 Olivier Rütti (EPFL) (olivier.rutti@a3.epfl.ch)
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package seqSamoa.protocols.fd;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import uka.transport.Transportable;
import framework.PID;
import framework.Constants;
import framework.GroupCommEventArgs;
import framework.GroupCommException;
import framework.libraries.Timer;
import framework.libraries.Trigger;
import framework.libraries.serialization.TSet;
import framework.libraries.serialization.TBoolean;
import framework.libraries.serialization.TMap;
import seqSamoa.AtomicTask;
import seqSamoa.ProtocolModule;
import seqSamoa.ProtocolStack;
import seqSamoa.Message;
import seqSamoa.ServiceCallOrResponse;
import seqSamoa.exceptions.AlreadyExistingProtocolModuleException;
import seqSamoa.exceptions.NotScheduledTaskException;
import seqSamoa.services.fd.FDSe;
import seqSamoa.services.fd.FDSeCallParameters;
import seqSamoa.services.fd.FDSeResponseParameters;
import seqSamoa.services.udp.UDP;
import seqSamoa.services.udp.UDPCallParameters;
/**
* This class implement a Protocol that detect distant process failure. It
* implement the failure detector needed by the consensus protocol described by
* Chandra and Toueg.
*
* This Protocol need a Protocol that implements UDP transport.
*
* The service implemented is FDSe (described in util/Services.java)
*/
public class ProtocolFDSe extends ProtocolModule implements Trigger, Timer {
final static int MAX_PROCESSES = 7;
// Service provided
private FDSe fdse;
// Service required
private UDP udp;
// The object containing the FDSe algorithm
static_recovery.common.fd.FDSe handlers = null;
// Is the Protocol Closed
boolean closed;
// Timers scheduled
Map<Transportable, AtomicTask> timers = null;
// The Executer
// It start to monitor the processes in parameters
protected FDSe.Executer fdSeExecuter;
// The Listener
// It wait for UDP message
protected UDP.Listener udpListener;
// The COR for call to fdse
private ServiceCallOrResponse fdSeCallCOR;
/**
* Constructor.
*
* @param name
* String identifier of the protocol
* @param stack
* The stack in which the module will be
* @param sendTimeOut
* The default sendTimeOut in ms.
* @param suspectRetries
* The number of timeout before suspecting a process
* @param storage
* The storage for recovery
* @param fdse
* Instance of service FDSe
* @param udp
* Instance of service UDP
*/
public ProtocolFDSe(String name, ProtocolStack stack, int sendTimeOut, int suspectRetries, FDSe fdse, UDP udp) throws AlreadyExistingProtocolModuleException {
super(name, stack);
this.fdse = fdse;
this.udp = udp;
this.fdSeCallCOR = ServiceCallOrResponse.createServiceCallOrResponse(this.fdse, true);
handlers = new static_recovery.common.fd.FDSe(this, this, stack.getStorage(),
sendTimeOut, suspectRetries, stack.getPID());
timers = new HashMap<Transportable, AtomicTask>();
LinkedList<ServiceCallOrResponse> initiatedFDSe = new LinkedList<ServiceCallOrResponse>();
for (int i=0;i<MAX_PROCESSES;i++)
initiatedFDSe.add(ServiceCallOrResponse.createServiceCallOrResponse(udp, true));
initiatedFDSe.add(ServiceCallOrResponse.createServiceCallOrResponse(fdse, false));
fdSeExecuter = fdse.new Executer(this, initiatedFDSe) {
public void evaluate(FDSeCallParameters params, Message dmessage) {
synchronized (this.parent) {
GroupCommEventArgs ga = new GroupCommEventArgs();
ga.addLast(params.startMonitoring);
ga.addLast(params.stopMonitoring);
try {
handlers.handleStartStopMonitor(ga);
} catch (GroupCommException ex) {
throw new RuntimeException("ProtocolFDSe: fdExecuter: "
+ ex.getMessage());
}
}
}
};
LinkedList<ServiceCallOrResponse> initiatedUdp = new LinkedList<ServiceCallOrResponse>();
initiatedUdp.add(ServiceCallOrResponse.createServiceCallOrResponse(udp, true));
initiatedUdp.add(ServiceCallOrResponse.createServiceCallOrResponse(fdse, false));
udpListener = udp.new Listener(this, initiatedUdp) {
public void evaluate(Object infos, Transportable response) {
synchronized (this.parent) {
GroupCommEventArgs ga = new GroupCommEventArgs();
ga.addLast(response);
handlers.handleUDPReceive(ga);
}
}
};
}
synchronized public void recovery(boolean recovery) {
GroupCommEventArgs e = new GroupCommEventArgs();
e.add(new TBoolean(recovery));
try {
handlers.handleRecovery(e);
} catch (GroupCommException ex) {
throw new RuntimeException("ProtocolFDSe: Recovery: "
+ ex.getMessage());
}
}
synchronized public void close() {
closed = true;
super.close();
}
synchronized public void dump(OutputStream os) {
handlers.dump(os);
}
/**
* Manage the triggering of the events
*/
public void trigger(int type, GroupCommEventArgs l) {
switch (type) {
case Constants.TRUST_SE:
FDSeResponseParameters infos = new FDSeResponseParameters((TSet) l
.remove(0), (TMap) l.remove(0));
fdse.response(infos, null);
break;
case Constants.UDPSEND:
Transportable message = l.remove(0);
UDPCallParameters params = new UDPCallParameters((PID) l.remove(0));
udp.call(params, new Message(message, udpListener));
break;
default:
throw new RuntimeException("ProtocolFDSe: trigger: "
+ "Trying to send an unknown event type: " + type);
}
}
private synchronized void timeout(Object o) {
GroupCommEventArgs args = new GroupCommEventArgs();
final Transportable key = (Transportable) o;
if (!timers.containsKey(key))
// Timer was canceled
return;
args.add(key);
handlers.handleTimeOut(args);
}
// Interface for the timers
synchronized public void schedule(final Transportable key,
boolean periodic, int time) {
if (!periodic) {
throw new RuntimeException("ProtocolFDSe: schedule: "
+ "Non-periodic timers not supported!!!");
}
if (timers.containsKey(key))
throw new RuntimeException(
"ProtocolFDSe: schedule: Task already scheduled!");
// There is no entry in the map
// Create the entry and start the timer
AtomicTask trigger = new AtomicTask() {
public void execute() {
timeout(key);
}
public ServiceCallOrResponse getCOR(){
return fdSeCallCOR;
}
};
timers.put(key, trigger);
stack.getScheduler().schedule(trigger, periodic, time);
}
synchronized public void cancel(Transportable key) {
try {
stack.getScheduler().cancel(timers.remove(key));
} catch (NotScheduledTaskException ex) {
throw new RuntimeException("ProtocolPing: cancel: The task is not"
+ " currently scheduled");
}
}
synchronized public void reset(Transportable key) {
try {
stack.getScheduler().reset(timers.get(key));
} catch (NotScheduledTaskException ex) {
throw new RuntimeException("ProtocolPing: reset: The task is not"
+ " currently scheduled");
}
}
}