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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.tuscany.sca.guardian;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.osoa.sca.annotations.Scope;
import org.apache.tuscany.sca.guardian.exceptions.*;
import org.osoa.sca.annotations.Service;
@Service(GuardianGroup.class)
@Scope("COMPOSITE")
public class GuardianGroupImpl implements GuardianGroup {
List<GuardianMember> guardianMembers;
public GuardianGroupImpl() {
guardianMembers = new LinkedList<GuardianMember>();
}
public void addGuardianMember(GuardianMember guardianMember) {
guardianMembers.add(guardianMember);
guardianMember.setUniqueParticipantID(guardianMembers.size() - 1);
}
public void enableContext(Context context) {
throw new UnsupportedOperationException("Not supported yet.");
}
public void removeContext() {
throw new UnsupportedOperationException("Not supported yet.");
}
public void gthrow(GlobalException ex, List<String> participantList) {
//1)Ivoked by a GuardianMember instance through the gthrow method
//2)Notify all participants about the exception (FIFO atomic broadcast model) - it will cause the suspension of all participants
// 2.1)Invoke the gthrow of the guardian members associated with the participants on participantList
//Sends a message representing the exception to the other guardian members
if (participantList == null) {
for (GuardianMember g : guardianMembers) {
if (!g.getParticipantIdentifier().equals(ex.getSignalingParticipant())) {
//g.gthrow(ex, participantList);
g.gthrow(null, null);
}
}
} else {
for (GuardianMember g : guardianMembers) {
if (participantList.contains(g.getCurrentContext())) {
//g.gthrow(ex, participantList);
g.gthrow(null, null);
}
}
}
//Check if the participants are blocked
List<Integer> flags = new ArrayList<Integer>(guardianMembers.size());
for (int i = 0; i < guardianMembers.size(); i++) {
if (guardianMembers.get(i).getService().isBlocked()) {
flags.add(i, 1);
} else {
flags.add(i, 0);
}
}
//Wait until all participants are blocked
while (flags.contains(0)) {
try {
Thread.sleep(5000);
} catch (InterruptedException ex1) {
Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex1);
}
}
//3)Once ALL required participants are SUSPENDED (suspended point), invoke the defined Recovery Rules
for (GuardianMember g : guardianMembers) {
g.addException(new SuspendException());
}
// 3.1) recovery_rules < signaled exceptions + context information of all participant > target context + exception to raise
//Simpleste Recovery Rule: broadcast the exception for all participants - FIXME: hardcoded
// for (GuardianMemberImpl g : guardianMembers) {
// ex.setTargetContext(Context.CURRENT_CONTEXT);
// g.addException(ex);
// }
//HARDCODED - SERVER-BACKUP EXAMPLE
//Rule 1
if (ex instanceof JoinException) {
if (guardianMembers.size() > 1) {
PrimaryExistsException primaryExists = new PrimaryExistsException();
primaryExists.setTargetContext(new Context("MAIN"));
BackupJoinedException backupJoined = new BackupJoinedException();
backupJoined.setTargetContext(new Context("PRIMARY"));
for (GuardianMember g : guardianMembers) {
//let p = JoinException.signaler
if (g.getParticipantIdentifier().equals(ex.getSignalingParticipant())) {
g.addException(primaryExists);
System.out.println("adding PrimaryExistsException to " + g.getParticipantIdentifier());
} else {
g.addException(backupJoined);
System.out.println("adding BackupJoinedException to " + g.getParticipantIdentifier());
}
}
}
} //Rule 2
else if (ex instanceof PrimaryFailedException) {
PrimaryFailedException primaryFailedInit = new PrimaryFailedException();
primaryFailedInit.setTargetContext(Context.INIT_CONTEXT);
PrimaryFailedException primaryFailedMain = new PrimaryFailedException();
primaryFailedMain.setTargetContext(new Context("MAIN"));
for (GuardianMember g : guardianMembers) {
if (g.getCurrentContext().getName().equals("PRIMARY")) {
System.out.println("adding PrimaryFailedException to " + g.getParticipantIdentifier());
g.addException(primaryFailedInit);
} else if (g.getCurrentContext().getName().equals("BACKUP")) {
System.out.println("adding PrimaryFailedException to " + g.getParticipantIdentifier());
g.addException(primaryFailedMain);
}
}
} //Rule 3
else if (ex instanceof BackupFailedException) {
BackupFailedException backupFailedPrimary = new BackupFailedException();
backupFailedPrimary.setTargetContext(new Context("PRIMARY"));
BackupFailedException backupFailedInit = new BackupFailedException();
backupFailedInit.setTargetContext(Context.INIT_CONTEXT);
for (GuardianMember g : guardianMembers) {
if (g.getCurrentContext().getName().equals("PRIMARY")) {
System.out.println("adding BackupFailedException to " + g.getParticipantIdentifier());
g.addException(backupFailedPrimary);
} else if (g.getCurrentContext().getName().equals("BACKUP")) {
System.out.println("adding BackupFailedException to " + g.getParticipantIdentifier());
g.addException(backupFailedInit);
}
}
}
}
public boolean propagate(GlobalException ex) {
throw new UnsupportedOperationException("Not supported yet.");
}
public void checkExceptionStatus() {
throw new UnsupportedOperationException("Not supported yet.");
}
public boolean removeGuardianMember(GuardianMember guardianMember) {
return this.guardianMembers.remove(guardianMember);
}
}
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