Exemple #1
0
  private static String lock(String lock) {
    String realPath = "";
    String parent = "/lock";
    String lockName = parent + "/" + lock;

    logger.debug("Getting lock " + lockName);

    try {
      if (zkInstance.exists(parent, false) == null)
        zkInstance.create(parent, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.fromFlag(0));
    } catch (Exception E) {
      logger.error("Error creating lock node: " + E.toString());
      return null;
    }

    List<String> children = new LinkedList<String>();
    try {
      // List <ACL> ACLList = zkInstance.getACL(lockName, zkInstance.exists(lock, false));

      realPath =
          zkInstance.create(
              lockName, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
      // children = zkInstance.getChildren(realPath, false);
      checkLock:
      while (true) {
        children = zkInstance.getChildren(parent, false);
        for (String curChild : children) {
          String child = parent + "/" + curChild;
          // System.out.println(child + " " + realPath + " " +
          // Integer.toString(child.compareTo(realPath)));
          if (child.compareTo(realPath) < 0
              && child.length() == realPath.length()
              && curChild.startsWith(lock)) {
            // System.out.println(child + " cmp to " + realPath);
            Thread.sleep(300);
            continue checkLock;
          }
        }
        logger.info("Got lock " + lockName);
        return realPath;
      }
    } catch (Exception E) {
      logger.error("Exception while trying to get lock " + lockName + " :" + E.toString());
      E.printStackTrace();
      return null;
    }
  }
Exemple #2
0
 private static boolean unlock(String lock) {
   logger.info("Releasing lock " + lock);
   try {
     zkInstance.delete(lock, -1);
   } catch (Exception E) {
     logger.debug("Error releasing lock: " + E.toString());
     return true;
   }
   return true;
 }