You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@zookeeper.apache.org by "Patrick Hunt (Assigned) (JIRA)" <ji...@apache.org> on 2012/03/15 22:16:39 UTC
[jira] [Assigned] (ZOOKEEPER-1418) Just a bug in the tutorial code
on the website
[ https://issues.apache.org/jira/browse/ZOOKEEPER-1418?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Patrick Hunt reassigned ZOOKEEPER-1418:
---------------------------------------
Assignee: Joe Gamache
> Just a bug in the tutorial code on the website
> ----------------------------------------------
>
> Key: ZOOKEEPER-1418
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1418
> Project: ZooKeeper
> Issue Type: Bug
> Components: documentation
> Affects Versions: 3.4.3
> Reporter: Joe Gamache
> Assignee: Joe Gamache
> Priority: Minor
>
> When I ran the Queue example from here: http://zookeeper.apache.org/doc/trunk/zookeeperTutorial.html
> The producer created entries of the form: /app1/element0000000001...
> but the consumer tried to consume of the form: /app1/element1...
> I fixed the code, but don't see how to attach a file?? Ok, here is the code:
> import java.io.IOException;
> import java.net.InetAddress;
> import java.net.UnknownHostException;
> import java.nio.ByteBuffer;
> import java.util.List;
> import java.util.Random;
> import org.apache.zookeeper.CreateMode;
> import org.apache.zookeeper.KeeperException;
> import org.apache.zookeeper.WatchedEvent;
> import org.apache.zookeeper.Watcher;
> import org.apache.zookeeper.ZooKeeper;
> import org.apache.zookeeper.ZooDefs.Ids;
> import org.apache.zookeeper.data.Stat;
> public class SyncPrimitive implements Watcher {
> static ZooKeeper zk = null;
> static Integer mutex;
> String root;
> 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);
> }
> synchronized public void process(WatchedEvent event) {
> synchronized (mutex) {
> //System.out.println("Process: " + event.getType());
> mutex.notify();
> }
> }
> /**
> * Barrier
> */
> static public class Barrier extends SyncPrimitive {
> int size;
> String name;
> /**
> * Barrier constructor
> *
> * @param address
> * @param root
> * @param size
> */
> Barrier(String address, String root, int size) {
> super(address);
> this.root = root;
> this.size = size;
> // Create barrier node
> if (zk != null) {
> try {
> Stat s = zk.exists(root, false);
> if (s == null) {
> zk.create(root, new byte[0], Ids.OPEN_ACL_UNSAFE,
> CreateMode.PERSISTENT);
> }
> } catch (KeeperException e) {
> System.out
> .println("Keeper exception when instantiating queue: "
> + e.toString());
> } catch (InterruptedException e) {
> System.out.println("Interrupted exception");
> }
> }
> // My node name
> try {
> name = new String(InetAddress.getLocalHost().getCanonicalHostName().toString());
> } catch (UnknownHostException e) {
> System.out.println(e.toString());
> }
> }
> /**
> * Join barrier
> *
> * @return
> * @throws KeeperException
> * @throws InterruptedException
> */
> boolean enter() throws KeeperException, InterruptedException{
> zk.create(root + "/" + name, new byte[0], Ids.OPEN_ACL_UNSAFE,
> CreateMode.EPHEMERAL_SEQUENTIAL);
> while (true) {
> synchronized (mutex) {
> List<String> list = zk.getChildren(root, true);
> if (list.size() < size) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> }
> /**
> * Wait until all reach barrier
> *
> * @return
> * @throws KeeperException
> * @throws InterruptedException
> */
> boolean leave() throws KeeperException, InterruptedException{
> zk.delete(root + "/" + name, 0);
> while (true) {
> synchronized (mutex) {
> List<String> list = zk.getChildren(root, true);
> if (list.size() > 0) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> }
> }
> /**
> * Producer-Consumer queue
> */
> static public class Queue extends SyncPrimitive {
> /**
> * Constructor of producer-consumer queue
> *
> * @param address
> * @param name
> */
> Queue(String address, String name) {
> super(address);
> this.root = name;
> // Create ZK node name
> if (zk != null) {
> try {
> Stat s = zk.exists(root, false);
> if (s == null) {
> zk.create(root, new byte[0], Ids.OPEN_ACL_UNSAFE,
> CreateMode.PERSISTENT);
> }
> } catch (KeeperException e) {
> System.out
> .println("Keeper exception when instantiating queue: "
> + e.toString());
> } catch (InterruptedException e) {
> System.out.println("Interrupted exception");
> }
> }
> }
> /**
> * Add element to the queue.
> *
> * @param i
> * @return
> */
> boolean produce(int i) throws KeeperException, InterruptedException{
> ByteBuffer b = ByteBuffer.allocate(4);
> byte[] value;
> // Add child with value i
> b.putInt(i);
> value = b.array();
> zk.create(root + "/element", value, Ids.OPEN_ACL_UNSAFE,
> CreateMode.PERSISTENT_SEQUENTIAL);
> return true;
> }
> /**
> * Remove first element from the queue.
> *
> * @return
> * @throws KeeperException
> * @throws InterruptedException
> */
> int consume() throws KeeperException, InterruptedException{
> int retvalue = -1;
> Stat stat = null;
> // Get the first element available
> while (true) {
> synchronized (mutex) {
> List<String> list = zk.getChildren(root, true);
> if (list.size() == 0) {
> System.out.println("Going to wait");
> mutex.wait();
> } else {
> Integer min = new Integer(list.get(0).substring(7));
> for(String s : list){
> Integer tempValue = new Integer(s.substring(7));
> //System.out.println("Temporary value: " + tempValue);
> if(tempValue < min) min = tempValue;
> }
> StringBuilder nodeBuilder = new StringBuilder("/element");
> String min_string = "" + min;
> for (int most=10; most>min_string.length(); most--) {
> nodeBuilder.append("0");
> }
> nodeBuilder.append(min);
> String element = nodeBuilder.toString();
>
> System.out.println("Temporary value: " + root + element + min);
> byte[] b = zk.getData(root + element + min,
> false, stat);
> zk.delete(root + element + min, 0);
> ByteBuffer buffer = ByteBuffer.wrap(b);
> retvalue = buffer.getInt();
> return retvalue;
> }
> }
> }
> }
> }
> public static void main(String args[]) {
> if (args[0].equals("qTest"))
> queueTest(args);
> else
> barrierTest(args);
> }
> public static void queueTest(String args[]) {
> Queue q = new Queue(args[1], "/app1");
> System.out.println("Input: " + args[1]);
> int i;
> Integer max = new Integer(args[2]);
> if (args[3].equals("p")) {
> System.out.println("Producer");
> for (i = 0; i < max; i++)
> try{
> q.produce(10 + i);
> } catch (KeeperException e){
> } catch (InterruptedException e){
> }
> } else {
> System.out.println("Consumer");
> for (i = 0; i < max; i++) {
> try{
> int r = q.consume();
> System.out.println("Item: " + r);
> } catch (KeeperException e){
> i--;
> } catch (InterruptedException e){
> }
> }
> }
> }
> public static void barrierTest(String args[]) {
> Barrier b = new Barrier(args[1], "/b1", new Integer(args[2]));
> try{
> boolean flag = b.enter();
> System.out.println("Entered barrier: " + args[2]);
> if(!flag) System.out.println("Error when entering the barrier");
> } catch (KeeperException e){
> } catch (InterruptedException e){
> }
> // Generate random integer
> Random rand = new Random();
> int r = rand.nextInt(100);
> // Loop for rand iterations
> for (int i = 0; i < r; i++) {
> try {
> Thread.sleep(100);
> } catch (InterruptedException e) {
> }
> }
> try{
> b.leave();
> } catch (KeeperException e){
> } catch (InterruptedException e){
> }
> System.out.println("Left barrier");
> }
> }
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira