package org.jgroups.demos;
import org.jgroups.JChannel;
import org.jgroups.blocks.locking.LockNotification;
import org.jgroups.blocks.locking.LockService;
import org.jgroups.jmx.JmxConfigurator;
import org.jgroups.util.Owner;
import org.jgroups.util.Util;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
/**
* Demos the LockService
*/
public class LockServiceDemo implements LockNotification {
protected String props;
protected JChannel ch;
protected LockService lock_service;
protected String name;
public LockServiceDemo(String props, String name) {
this.props=props;
this.name=name;
}
public void start() throws Exception {
ch=new JChannel(props);
if(name != null)
ch.setName(name);
lock_service=new LockService(ch);
lock_service.addLockListener(this);
ch.connect("lock-cluster");
JmxConfigurator.registerChannel(ch, Util.getMBeanServer(), "lock-service", ch.getClusterName(), true);
try {
loop();
}
catch(Exception e) {
e.printStackTrace();
}
finally {
Util.close(ch);
}
}
public void start(JChannel ch) throws Exception {
this.ch=ch;
lock_service=new LockService(ch);
lock_service.addLockListener(this);
ch.connect("lock-cluster");
JmxConfigurator.registerChannel(ch, Util.getMBeanServer(), "lock-service", ch.getClusterName(), true);
try {
loop();
}
catch(Exception e) {
e.printStackTrace();
}
finally {
Util.close(ch);
}
}
public void lockCreated(String name) {
}
public void lockDeleted(String name) {
}
public void locked(String lock_name, Owner owner) {
System.out.println("\"" + lock_name + "\" locked by " + owner);
}
public void unlocked(String lock_name, Owner owner) {
System.out.println("\"" + lock_name + "\" unlocked by " + owner);
}
public void awaiting(String lock_name, Owner owner) {
System.out.println("awaiting \"" + lock_name + "\" by " + owner);
}
public void awaited(String lock_name, Owner owner) {
System.out.println("awaited \"" + lock_name + "\" by " + owner);
}
protected void loop() throws Exception {
List<String> lock_names;
while(ch.isConnected()) {
String line=Util.readStringFromStdin(": ");
if(line.startsWith("quit") || line.startsWith("exit"))
break;
if(line.startsWith("lock")) {
lock_names=parseLockNames(line.substring("lock".length()).trim());
for(String lock_name: lock_names) {
Lock lock=lock_service.getLock(lock_name);
lock.lock();
}
}
else if(line.startsWith("trylock")) {
lock_names=parseLockNames(line.substring("trylock".length()).trim());
String tmp=lock_names.get(lock_names.size() -1);
Long timeout=(long)-1;
try {
timeout=Long.parseLong(tmp);
lock_names.remove(lock_names.size() -1);
}
catch(NumberFormatException e) {
}
for(String lock_name: lock_names) {
Lock lock=lock_service.getLock(lock_name);
boolean rc;
if(timeout < 0)
rc=lock.tryLock();
else
rc=lock.tryLock(timeout, TimeUnit.MILLISECONDS);
if(!rc)
System.err.println("Failed locking \"" + lock_name + "\"");
}
}
else if(line.startsWith("unlock")) {
lock_names=parseLockNames(line.substring("unlock".length()).trim());
for(String lock_name: lock_names) {
if(lock_name.equalsIgnoreCase("all")) {
lock_service.unlockAll();
break;
}
else {
Lock lock=lock_service.getLock(lock_name);
if(lock != null)
lock.unlock();
}
}
}
else if(line.startsWith("view"))
System.out.println("View: " + ch.getView());
else if(line.startsWith("help"))
help();
printLocks();
}
}
protected static List<String> parseLockNames(String line) {
List<String> lock_names=new ArrayList<String>();
if(line == null || line.isEmpty())
return lock_names;
StringTokenizer tokenizer=new StringTokenizer(line);
while(tokenizer.hasMoreTokens())
lock_names.add(tokenizer.nextToken());
return lock_names;
}
protected void printLocks() {
System.out.println("\n" + lock_service.printLocks());
}
public static void main(String[] args) throws Exception {
String props=null;
String name=null;
for(int i=0; i < args.length; i++) {
if(args[i].equals("-props")) {
props=args[++i];
continue;
}
if(args[i].equals("-name")) {
name=args[++i];
continue;
}
help();
return;
}
LockServiceDemo demo=new LockServiceDemo(props, name);
demo.start();
}
protected static void help() {
System.out.println("\nLockServiceDemo [-props properties] [-name name]\n" +
"Valid commands:\n\n" +
"lock (<lock name>)+\n" +
"unlock (<lock name> | \"ALL\")+\n" +
"trylock (<lock name>)+ [<timeout>]\n");
System.out.println("Example:\nlock lock lock2 lock3\nunlock all\ntrylock bela michelle 300");
}
}