Synchronous primitive in zk

Laboratory structure

• Every instance is a watcher, when event be triggered
  process method will be callback.

  public class SyncPrimitive implements Watcher

• Properties

  // share zk client
  static ZooKeeper zk = null;
  // share lock mointor
  static Integer mutex;
  // instance zk path
  String root;

• Constructor

  SyncPrimitive(String address) {
      if(zk == null){
          try {
              System.out.println("Starting ZK:");
              zk = new ZooKeeper(address, 3000, this);
              mutex = new Integer(-1);
              System.out.println("Finished starting ZK: " + zk);
          } catch (IOException e) {
              System.out.println(e.toString());
              zk = null;
          }
      }
      // else mutex = new Integer(-1);
  }

  1. if the common zk client not exists, create one
  2. create the lock monitor by the way
  3. if not init the propertiy mutex is 0.

• Implements abstract method

synchronized public void process(WatchedEvent event) {
    synchronized (mutex) {
        mutex.notify();
    }
}

If the thread have monitor, call one another.
If not, wait for monitor mutex unlock.