gistfile1.java

public class Test {
    private static final TestingServer server;
    private static final CuratorFramework client;
    static
    {
        TestingServer localServer = null;
        CuratorFramework localClient = null;
        try
        {
            localServer = new TestingServer();
            localClient = CuratorFrameworkFactory.newClient(localServer.getConnectString(), new ExponentialBackoffRetry(10, 5));
        }
        catch ( Exception e )
        {
            e.printStackTrace();
            System.exit(0);
        }

        server = localServer;
        client = localClient;
    }

    public static void main(String[] args) {
        client.start();
        int numLocks = 50000;
        int numThreads = 200;
        String[] keyPool = new String[numLocks];
        for (int i = 1; i <= numLocks; i++) {
            keyPool[i - 1] = String.valueOf(100 + i);
        }
        for (int i = 0; i < numThreads; i++) {
            Thread t = new Thread(new Job(numLocks, keyPool));
            t.setName("T" + (i + 1));
            t.start();
        }
    }

    private static class Job implements Runnable {
        private int      numLocks;
        private String[] keyPool;

        public Job(int numLocks, String[] keyPool) {
            this.numLocks = numLocks;
            this.keyPool = keyPool;
        }

        @Override
        public void run() {
            while (true) {
                int l = 0;
                int h = numLocks;
                String lockKey = keyPool[(new Random().nextInt(h - l) + l)];
                InterProcessMutex lock = new InterProcessMutex(client, "/"+lockKey);
                boolean acquired = false;
                String threadName = Thread.currentThread().getName();
                try {
                    long start = System.currentTimeMillis();
                    acquired = lock.acquire(0, TimeUnit.NANOSECONDS);
                    if (acquired) {
                        long end = System.currentTimeMillis();
                        System.out.println("lock acquired in "+ (end - start) + " ms");
                    } else {
                        System.out.println("failed to get lock");
                    }
                } catch (Exception e) {
                    System.out.println(e);
                } finally {
                    if (acquired) {
                        long start = System.currentTimeMillis();
                        try
                        {
                            lock.release();
                        }
                        catch ( Exception e )
                        {
                            System.err.println("Couldn't release lock");
                        }
                        long end = System.currentTimeMillis();
                        System.out.println("lock released in "+(end - start)+" ms");
                    }
                }
            }
        }
    }
}

@Randgalt The performance is terrible using a vanilla installation of ZooKeeper. Locks take anywhere from 80ms to 300ms to be acquired.