Comment utiliser les verrous distribués en Java pour réaliser la synchronisation des systèmes distribués ?

import org.apache.zookeeper.*; import java.io.IOException; import java.util.Collections; import java.util.List; public class ZooKeeperDistributedLock implements Watcher { private ZooKeeper zooKeeper; private String lockPath; private String currentPath; private String waitPath; public ZooKeeperDistributedLock(String connectString, int sessionTimeout, String lockPath) throws IOException { zooKeeper = new ZooKeeper(connectString, sessionTimeout, this); this.lockPath = lockPath; } public void lock() throws KeeperException, InterruptedException { if (tryLock()) { return; } while (true) { List children = zooKeeper.getChildren(lockPath, false); Collections.sort(children); int index = children.indexOf(currentPath.substring(lockPath.length() + 1)); if (index == 0) { return; } waitPath = lockPath + "/" + children.get(index - 1); zooKeeper.exists(waitPath, true); synchronized (this) { wait(); } } } public void unlock() throws KeeperException, InterruptedException { zooKeeper.delete(currentPath, -1); } private boolean tryLock() throws KeeperException, InterruptedException { currentPath = zooKeeper.create(lockPath + "/lock", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL); List children = zooKeeper.getChildren(lockPath, false); Collections.sort(children); if (currentPath.endsWith(children.get(0))) { return true; } String currentPathName = currentPath.substring(lockPath.length() + 1); int index = children.indexOf(currentPathName); if (index < 0) { throw new IllegalStateException("Node " + currentPathName + " no longer exists."); } else { waitPath = lockPath + "/" + children.get(index - 1); zooKeeper.exists(waitPath, true); synchronized (this) { wait(); } return false; } } @Override public void process(WatchedEvent event) { if (waitPath != null && event.getType() == Event.EventType.NodeDeleted && event.getPath().equals(waitPath)) { synchronized (this) { notifyAll(); } } } }

import redis.clients.jedis.Jedis; public class RedisDistributedLock { private Jedis jedis; private String lockKey; private String requestId; public RedisDistributedLock(String host, int port, String password, String lockKey, String requestId) { jedis = new Jedis(host, port); jedis.auth(password); this.lockKey = lockKey; this.requestId = requestId; } public boolean lock(long expireTimeMillis) { String result = jedis.set(lockKey, requestId, "NX", "PX", expireTimeMillis); return "OK".equals(result); } public boolean unlock() { Long result = (Long) jedis.eval( "if redis.call('get', KEYS[1]) == ARGV[1] then " + "return redis.call('del', KEYS[1]) " + "else " + "return 0 " + "end", 1, lockKey, requestId); return result != null && result == 1; } }