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Posted to commits@zookeeper.apache.org by an...@apache.org on 2018/07/17 08:38:43 UTC

[03/10] zookeeper git commit: ZOOKEEPER-3033: branch-3.4 - MAVEN MIGRATION - Step 1.2 - zk-recipes

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/src/c/tests/zkServer.sh
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diff --git a/zookeeper-recipes/lock/src/c/tests/zkServer.sh b/zookeeper-recipes/lock/src/c/tests/zkServer.sh
new file mode 100755
index 0000000..a22fd30
--- /dev/null
+++ b/zookeeper-recipes/lock/src/c/tests/zkServer.sh
@@ -0,0 +1,75 @@
+#!/bin/bash
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+if [ "x$1" == "x" ]
+then
+	echo "USAGE: $0 startClean|start|stop hostPorts"
+	exit 2
+fi
+
+if [ "x$1" == "xstartClean" ]
+then
+	rm -rf /tmp/zkdata
+fi
+
+# Make sure nothing is left over from before
+if [ -r "/tmp/zk.pid" ]
+then
+pid=`cat /tmp/zk.pid`
+kill -9 $pid
+rm -f /tmp/zk.pid
+fi
+
+base_dir="../../../../.."
+
+CLASSPATH="$CLASSPATH:${base_dir}/build/classes"
+CLASSPATH="$CLASSPATH:${base_dir}/conf"
+
+for f in "${base_dir}"/zookeeper-*.jar
+do
+    CLASSPATH="$CLASSPATH:$f"
+done
+
+for i in "${base_dir}"/build/lib/*.jar
+do
+    CLASSPATH="$CLASSPATH:$i"
+done
+
+for i in "${base_dir}"/src/java/lib/*.jar
+do
+    CLASSPATH="$CLASSPATH:$i"
+done
+
+CLASSPATH="$CLASSPATH:${CLOVER_HOME}/lib/clover.jar"
+
+case $1 in
+start|startClean)
+	mkdir -p /tmp/zkdata
+	java -cp $CLASSPATH org.apache.zookeeper.server.ZooKeeperServerMain 22181 /tmp/zkdata &> /tmp/zk.log &
+        echo $! > /tmp/zk.pid
+        sleep 5
+	;;
+stop)
+	# Already killed above
+	;;
+*)
+	echo "Unknown command " + $1
+	exit 2
+esac
+

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/LockListener.java
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diff --git a/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/LockListener.java b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/LockListener.java
new file mode 100644
index 0000000..1c21ad6
--- /dev/null
+++ b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/LockListener.java
@@ -0,0 +1,38 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+/**
+ * This class has two methods which are call
+ * back methods when a lock is acquired and 
+ * when the lock is released.
+ *
+ */
+public interface LockListener {
+    /**
+     * call back called when the lock 
+     * is acquired
+     */
+    public void lockAcquired();
+    
+    /**
+     * call back called when the lock is 
+     * released.
+     */
+    public void lockReleased();
+}

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ProtocolSupport.java
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diff --git a/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ProtocolSupport.java b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ProtocolSupport.java
new file mode 100644
index 0000000..4efdb85
--- /dev/null
+++ b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ProtocolSupport.java
@@ -0,0 +1,193 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.ZooDefs;
+import org.apache.zookeeper.ZooKeeper;
+import org.apache.zookeeper.data.ACL;
+import org.apache.zookeeper.data.Stat;
+import org.apache.zookeeper.recipes.lock.ZooKeeperOperation;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * A base class for protocol implementations which provides a number of higher 
+ * level helper methods for working with ZooKeeper along with retrying synchronous
+ *  operations if the connection to ZooKeeper closes such as 
+ *  {@link #retryOperation(ZooKeeperOperation)}
+ *
+ */
+class ProtocolSupport {
+    private static final Logger LOG = LoggerFactory.getLogger(ProtocolSupport.class);
+
+    protected final ZooKeeper zookeeper;
+    private AtomicBoolean closed = new AtomicBoolean(false);
+    private long retryDelay = 500L;
+    private int retryCount = 10;
+    private List<ACL> acl = ZooDefs.Ids.OPEN_ACL_UNSAFE;
+
+    public ProtocolSupport(ZooKeeper zookeeper) {
+        this.zookeeper = zookeeper;
+    }
+
+    /**
+     * Closes this strategy and releases any ZooKeeper resources; but keeps the
+     *  ZooKeeper instance open
+     */
+    public void close() {
+        if (closed.compareAndSet(false, true)) {
+            doClose();
+        }
+    }
+    
+    /**
+     * return zookeeper client instance
+     * @return zookeeper client instance
+     */
+    public ZooKeeper getZookeeper() {
+        return zookeeper;
+    }
+
+    /**
+     * return the acl its using
+     * @return the acl.
+     */
+    public List<ACL> getAcl() {
+        return acl;
+    }
+
+    /**
+     * set the acl 
+     * @param acl the acl to set to
+     */
+    public void setAcl(List<ACL> acl) {
+        this.acl = acl;
+    }
+
+    /**
+     * get the retry delay in milliseconds
+     * @return the retry delay
+     */
+    public long getRetryDelay() {
+        return retryDelay;
+    }
+
+    /**
+     * Sets the time waited between retry delays
+     * @param retryDelay the retry delay
+     */
+    public void setRetryDelay(long retryDelay) {
+        this.retryDelay = retryDelay;
+    }
+
+    /**
+     * Allow derived classes to perform 
+     * some custom closing operations to release resources
+     */
+    protected void doClose() {
+    }
+
+
+    /**
+     * Perform the given operation, retrying if the connection fails
+     * @return object. it needs to be cast to the callee's expected 
+     * return type.
+     */
+    protected Object retryOperation(ZooKeeperOperation operation) 
+        throws KeeperException, InterruptedException {
+        KeeperException exception = null;
+        for (int i = 0; i < retryCount; i++) {
+            try {
+                return operation.execute();
+            } catch (KeeperException.SessionExpiredException e) {
+                LOG.warn("Session expired for: " + zookeeper + " so reconnecting due to: " + e, e);
+                throw e;
+            } catch (KeeperException.ConnectionLossException e) {
+                if (exception == null) {
+                    exception = e;
+                }
+                LOG.debug("Attempt " + i + " failed with connection loss so " +
+                		"attempting to reconnect: " + e, e);
+                retryDelay(i);
+            }
+        }
+        throw exception;
+    }
+
+    /**
+     * Ensures that the given path exists with no data, the current
+     * ACL and no flags
+     * @param path
+     */
+    protected void ensurePathExists(String path) {
+        ensureExists(path, null, acl, CreateMode.PERSISTENT);
+    }
+
+    /**
+     * Ensures that the given path exists with the given data, ACL and flags
+     * @param path
+     * @param acl
+     * @param flags
+     */
+    protected void ensureExists(final String path, final byte[] data,
+            final List<ACL> acl, final CreateMode flags) {
+        try {
+            retryOperation(new ZooKeeperOperation() {
+                public boolean execute() throws KeeperException, InterruptedException {
+                    Stat stat = zookeeper.exists(path, false);
+                    if (stat != null) {
+                        return true;
+                    }
+                    zookeeper.create(path, data, acl, flags);
+                    return true;
+                }
+            });
+        } catch (KeeperException e) {
+            LOG.warn("Caught: " + e, e);
+        } catch (InterruptedException e) {
+            LOG.warn("Caught: " + e, e);
+        }
+    }
+
+    /**
+     * Returns true if this protocol has been closed
+     * @return true if this protocol is closed
+     */
+    protected boolean isClosed() {
+        return closed.get();
+    }
+
+    /**
+     * Performs a retry delay if this is not the first attempt
+     * @param attemptCount the number of the attempts performed so far
+     */
+    protected void retryDelay(int attemptCount) {
+        if (attemptCount > 0) {
+            try {
+                Thread.sleep(attemptCount * retryDelay);
+            } catch (InterruptedException e) {
+                LOG.debug("Failed to sleep: " + e, e);
+            }
+        }
+    }
+}

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/WriteLock.java
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diff --git a/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/WriteLock.java b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/WriteLock.java
new file mode 100644
index 0000000..5caebee
--- /dev/null
+++ b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/WriteLock.java
@@ -0,0 +1,296 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.WatchedEvent;
+import org.apache.zookeeper.Watcher;
+import static org.apache.zookeeper.CreateMode.EPHEMERAL_SEQUENTIAL;
+import org.apache.zookeeper.ZooKeeper;
+import org.apache.zookeeper.data.ACL;
+import org.apache.zookeeper.data.Stat;
+
+import java.util.List;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+/**
+ * A <a href="package.html">protocol to implement an exclusive
+ *  write lock or to elect a leader</a>. <p/> You invoke {@link #lock()} to 
+ *  start the process of grabbing the lock; you may get the lock then or it may be 
+ *  some time later. <p/> You can register a listener so that you are invoked 
+ *  when you get the lock; otherwise you can ask if you have the lock
+ *  by calling {@link #isOwner()}
+ *
+ */
+public class WriteLock extends ProtocolSupport {
+    private static final Logger LOG = LoggerFactory.getLogger(WriteLock.class);
+
+    private final String dir;
+    private String id;
+    private ZNodeName idName;
+    private String ownerId;
+    private String lastChildId;
+    private byte[] data = {0x12, 0x34};
+    private LockListener callback;
+    private LockZooKeeperOperation zop;
+    
+    /**
+     * zookeeper contructor for writelock
+     * @param zookeeper zookeeper client instance
+     * @param dir the parent path you want to use for locking
+     * @param acls the acls that you want to use for all the paths, 
+     * if null world read/write is used.
+     */
+    public WriteLock(ZooKeeper zookeeper, String dir, List<ACL> acl) {
+        super(zookeeper);
+        this.dir = dir;
+        if (acl != null) {
+            setAcl(acl);
+        }
+        this.zop = new LockZooKeeperOperation();
+    }
+    
+    /**
+     * zookeeper contructor for writelock with callback
+     * @param zookeeper the zookeeper client instance
+     * @param dir the parent path you want to use for locking
+     * @param acl the acls that you want to use for all the paths
+     * @param callback the call back instance
+     */
+    public WriteLock(ZooKeeper zookeeper, String dir, List<ACL> acl, 
+            LockListener callback) {
+        this(zookeeper, dir, acl);
+        this.callback = callback;
+    }
+
+    /**
+     * return the current locklistener
+     * @return the locklistener
+     */
+    public LockListener getLockListener() {
+        return this.callback;
+    }
+    
+    /**
+     * register a different call back listener
+     * @param callback the call back instance
+     */
+    public void setLockListener(LockListener callback) {
+        this.callback = callback;
+    }
+
+    /**
+     * Removes the lock or associated znode if 
+     * you no longer require the lock. this also 
+     * removes your request in the queue for locking
+     * in case you do not already hold the lock.
+     * @throws RuntimeException throws a runtime exception
+     * if it cannot connect to zookeeper.
+     */
+    public synchronized void unlock() throws RuntimeException {
+        
+        if (!isClosed() && id != null) {
+            // we don't need to retry this operation in the case of failure
+            // as ZK will remove ephemeral files and we don't wanna hang
+            // this process when closing if we cannot reconnect to ZK
+            try {
+                
+                ZooKeeperOperation zopdel = new ZooKeeperOperation() {
+                    public boolean execute() throws KeeperException,
+                        InterruptedException {
+                        zookeeper.delete(id, -1);   
+                        return Boolean.TRUE;
+                    }
+                };
+                zopdel.execute();
+            } catch (InterruptedException e) {
+                LOG.warn("Caught: " + e, e);
+                //set that we have been interrupted.
+               Thread.currentThread().interrupt();
+            } catch (KeeperException.NoNodeException e) {
+                // do nothing
+            } catch (KeeperException e) {
+                LOG.warn("Caught: " + e, e);
+                throw (RuntimeException) new RuntimeException(e.getMessage()).
+                    initCause(e);
+            }
+            finally {
+                if (callback != null) {
+                    callback.lockReleased();
+                }
+                id = null;
+            }
+        }
+    }
+    
+    /** 
+     * the watcher called on  
+     * getting watch while watching 
+     * my predecessor
+     */
+    private class LockWatcher implements Watcher {
+        public void process(WatchedEvent event) {
+            // lets either become the leader or watch the new/updated node
+            LOG.debug("Watcher fired on path: " + event.getPath() + " state: " + 
+                    event.getState() + " type " + event.getType());
+            try {
+                lock();
+            } catch (Exception e) {
+                LOG.warn("Failed to acquire lock: " + e, e);
+            }
+        }
+    }
+    
+    /**
+     * a zoookeeper operation that is mainly responsible
+     * for all the magic required for locking.
+     */
+    private  class LockZooKeeperOperation implements ZooKeeperOperation {
+        
+        /** find if we have been created earler if not create our node
+         * 
+         * @param prefix the prefix node
+         * @param zookeeper teh zookeeper client
+         * @param dir the dir paretn
+         * @throws KeeperException
+         * @throws InterruptedException
+         */
+        private void findPrefixInChildren(String prefix, ZooKeeper zookeeper, String dir) 
+            throws KeeperException, InterruptedException {
+            List<String> names = zookeeper.getChildren(dir, false);
+            for (String name : names) {
+                if (name.startsWith(prefix)) {
+                    id = name;
+                    if (LOG.isDebugEnabled()) {
+                        LOG.debug("Found id created last time: " + id);
+                    }
+                    break;
+                }
+            }
+            if (id == null) {
+                id = zookeeper.create(dir + "/" + prefix, data, 
+                        getAcl(), EPHEMERAL_SEQUENTIAL);
+
+                if (LOG.isDebugEnabled()) {
+                    LOG.debug("Created id: " + id);
+                }
+            }
+
+        }
+        
+        /**
+         * the command that is run and retried for actually 
+         * obtaining the lock
+         * @return if the command was successful or not
+         */
+        public boolean execute() throws KeeperException, InterruptedException {
+            do {
+                if (id == null) {
+                    long sessionId = zookeeper.getSessionId();
+                    String prefix = "x-" + sessionId + "-";
+                    // lets try look up the current ID if we failed 
+                    // in the middle of creating the znode
+                    findPrefixInChildren(prefix, zookeeper, dir);
+                    idName = new ZNodeName(id);
+                }
+                if (id != null) {
+                    List<String> names = zookeeper.getChildren(dir, false);
+                    if (names.isEmpty()) {
+                        LOG.warn("No children in: " + dir + " when we've just " +
+                        "created one! Lets recreate it...");
+                        // lets force the recreation of the id
+                        id = null;
+                    } else {
+                        // lets sort them explicitly (though they do seem to come back in order ususally :)
+                        SortedSet<ZNodeName> sortedNames = new TreeSet<ZNodeName>();
+                        for (String name : names) {
+                            sortedNames.add(new ZNodeName(dir + "/" + name));
+                        }
+                        ownerId = sortedNames.first().getName();
+                        SortedSet<ZNodeName> lessThanMe = sortedNames.headSet(idName);
+                        if (!lessThanMe.isEmpty()) {
+                            ZNodeName lastChildName = lessThanMe.last();
+                            lastChildId = lastChildName.getName();
+                            if (LOG.isDebugEnabled()) {
+                                LOG.debug("watching less than me node: " + lastChildId);
+                            }
+                            Stat stat = zookeeper.exists(lastChildId, new LockWatcher());
+                            if (stat != null) {
+                                return Boolean.FALSE;
+                            } else {
+                                LOG.warn("Could not find the" +
+                                		" stats for less than me: " + lastChildName.getName());
+                            }
+                        } else {
+                            if (isOwner()) {
+                                if (callback != null) {
+                                    callback.lockAcquired();
+                                }
+                                return Boolean.TRUE;
+                            }
+                        }
+                    }
+                }
+            }
+            while (id == null);
+            return Boolean.FALSE;
+        }
+    };
+
+    /**
+     * Attempts to acquire the exclusive write lock returning whether or not it was
+     * acquired. Note that the exclusive lock may be acquired some time later after
+     * this method has been invoked due to the current lock owner going away.
+     */
+    public synchronized boolean lock() throws KeeperException, InterruptedException {
+        if (isClosed()) {
+            return false;
+        }
+        ensurePathExists(dir);
+
+        return (Boolean) retryOperation(zop);
+    }
+
+    /**
+     * return the parent dir for lock
+     * @return the parent dir used for locks.
+     */
+    public String getDir() {
+        return dir;
+    }
+
+    /**
+     * Returns true if this node is the owner of the
+     *  lock (or the leader)
+     */
+    public boolean isOwner() {
+        return id != null && ownerId != null && id.equals(ownerId);
+    }
+
+    /**
+     * return the id for this lock
+     * @return the id for this lock
+     */
+    public String getId() {
+       return this.id;
+    }
+}
+

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZNodeName.java
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diff --git a/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZNodeName.java b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZNodeName.java
new file mode 100644
index 0000000..2e32e59
--- /dev/null
+++ b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZNodeName.java
@@ -0,0 +1,112 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Represents an ephemeral znode name which has an ordered sequence number
+ * and can be sorted in order
+ *
+ */
+class ZNodeName implements Comparable<ZNodeName> {
+    private final String name;
+    private String prefix;
+    private int sequence = -1;
+    private static final Logger LOG = LoggerFactory.getLogger(ZNodeName.class);
+    
+    public ZNodeName(String name) {
+        if (name == null) {
+            throw new NullPointerException("id cannot be null");
+        }
+        this.name = name;
+        this.prefix = name;
+        int idx = name.lastIndexOf('-');
+        if (idx >= 0) {
+            this.prefix = name.substring(0, idx);
+            try {
+                this.sequence = Integer.parseInt(name.substring(idx + 1));
+                // If an exception occurred we misdetected a sequence suffix,
+                // so return -1.
+            } catch (NumberFormatException e) {
+                LOG.info("Number format exception for " + idx, e);
+            } catch (ArrayIndexOutOfBoundsException e) {
+               LOG.info("Array out of bounds for " + idx, e);
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        return name.toString();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        ZNodeName sequence = (ZNodeName) o;
+
+        if (!name.equals(sequence.name)) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        return name.hashCode() + 37;
+    }
+
+    /**
+     * Compare znodes based on their sequence number
+     * @param that other znode to compare to
+     * @return the difference between their sequence numbers: a positive value if this
+     *         znode has a larger sequence number, 0 if they have the same sequence number
+     *         or a negative number if this znode has a lower sequence number
+     */
+    public int compareTo(ZNodeName that) {
+        int answer = this.sequence - that.sequence;
+        if (answer == 0) {
+            return this.prefix.compareTo(that.prefix);
+        }
+        return answer;
+    }
+
+    /**
+     * Returns the name of the znode
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Returns the sequence number
+     */
+    public int getZNodeName() {
+        return sequence;
+    }
+
+    /**
+     * Returns the text prefix before the sequence number
+     */
+    public String getPrefix() {
+        return prefix;
+    }
+}

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZooKeeperOperation.java
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZooKeeperOperation.java b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZooKeeperOperation.java
new file mode 100644
index 0000000..54317ed
--- /dev/null
+++ b/zookeeper-recipes/lock/src/java/org/apache/zookeeper/recipes/lock/ZooKeeperOperation.java
@@ -0,0 +1,38 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+import org.apache.zookeeper.KeeperException;
+
+/**
+ * A callback object which can be used for implementing retry-able operations in the 
+ * {@link org.apache.zookeeper.recipes.lock.ProtocolSupport} class
+ *
+ */
+public interface ZooKeeperOperation {
+    
+    /**
+     * Performs the operation - which may be involved multiple times if the connection
+     * to ZooKeeper closes during this operation
+     *
+     * @return the result of the operation or null
+     * @throws KeeperException
+     * @throws InterruptedException
+     */
+    public boolean execute() throws KeeperException, InterruptedException;
+}

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/WriteLockTest.java
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/WriteLockTest.java b/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/WriteLockTest.java
new file mode 100644
index 0000000..52f9f57
--- /dev/null
+++ b/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/WriteLockTest.java
@@ -0,0 +1,156 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+import org.apache.zookeeper.ZooKeeper;
+import org.apache.zookeeper.test.ClientBase;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * test for writelock
+ */
+public class WriteLockTest extends ClientBase {
+    protected int sessionTimeout = 10 * 1000;
+    protected String dir = "/" + getClass().getName();
+    protected WriteLock[] nodes;
+    protected CountDownLatch latch = new CountDownLatch(1);
+    private boolean restartServer = true;
+    private boolean workAroundClosingLastZNodeFails = true;
+    private boolean killLeader = true;
+
+    @Test
+    public void testRun() throws Exception {
+        runTest(3);
+    }
+
+    class LockCallback implements LockListener {
+        public void lockAcquired() {
+            latch.countDown();
+        }
+
+        public void lockReleased() {
+            
+        }
+        
+    }
+    protected void runTest(int count) throws Exception {
+        nodes = new WriteLock[count];
+        for (int i = 0; i < count; i++) {
+            ZooKeeper keeper = createClient();
+            WriteLock leader = new WriteLock(keeper, dir, null);
+            leader.setLockListener(new LockCallback());
+            nodes[i] = leader;
+
+            leader.lock();
+        }
+
+        // lets wait for any previous leaders to die and one of our new
+        // nodes to become the new leader
+        latch.await(30, TimeUnit.SECONDS);
+
+        WriteLock first = nodes[0];
+        dumpNodes(count);
+
+        // lets assert that the first election is the leader
+        Assert.assertTrue("The first znode should be the leader " + first.getId(), first.isOwner());
+
+        for (int i = 1; i < count; i++) {
+            WriteLock node = nodes[i];
+            Assert.assertFalse("Node should not be the leader " + node.getId(), node.isOwner());
+        }
+
+        if (count > 1) {
+            if (killLeader) {
+            System.out.println("Now killing the leader");
+            // now lets kill the leader
+            latch = new CountDownLatch(1);
+            first.unlock();
+            latch.await(30, TimeUnit.SECONDS);
+            //Thread.sleep(10000);
+            WriteLock second = nodes[1];
+            dumpNodes(count);
+            // lets assert that the first election is the leader
+            Assert.assertTrue("The second znode should be the leader " + second.getId(), second.isOwner());
+
+            for (int i = 2; i < count; i++) {
+                WriteLock node = nodes[i];
+                Assert.assertFalse("Node should not be the leader " + node.getId(), node.isOwner());
+            }
+            }
+
+
+            if (restartServer) {
+                // now lets stop the server
+                System.out.println("Now stopping the server");
+                stopServer();
+                Thread.sleep(10000);
+
+                // TODO lets assert that we are no longer the leader
+                dumpNodes(count);
+
+                System.out.println("Starting the server");
+                startServer();
+                Thread.sleep(10000);
+
+                for (int i = 0; i < count - 1; i++) {
+                    System.out.println("Calling acquire for node: " + i);
+                    nodes[i].lock();
+                }
+                dumpNodes(count);
+                System.out.println("Now closing down...");
+            }
+        }
+    }
+
+    protected void dumpNodes(int count) {
+        for (int i = 0; i < count; i++) {
+            WriteLock node = nodes[i];
+            System.out.println("node: " + i + " id: " + 
+                    node.getId() + " is leader: " + node.isOwner());
+        }
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        if (nodes != null) {
+            for (int i = 0; i < nodes.length; i++) {
+                WriteLock node = nodes[i];
+                if (node != null) {
+                    System.out.println("Closing node: " + i);
+                    node.close();
+                    if (workAroundClosingLastZNodeFails && i == nodes.length - 1) {
+                        System.out.println("Not closing zookeeper: " + i + " due to bug!");
+                    } else {
+                        System.out.println("Closing zookeeper: " + i);
+                        node.getZookeeper().close();
+                        System.out.println("Closed zookeeper: " + i);
+                    }
+                }
+            }
+        }
+        System.out.println("Now lets stop the server");
+        super.tearDown();
+
+    }
+}

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/ZNodeNameTest.java
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/ZNodeNameTest.java b/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/ZNodeNameTest.java
new file mode 100644
index 0000000..773c2ec
--- /dev/null
+++ b/zookeeper-recipes/lock/test/org/apache/zookeeper/recipes/lock/ZNodeNameTest.java
@@ -0,0 +1,71 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.recipes.lock;
+
+import junit.framework.TestCase;
+
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+import org.junit.Test;
+
+/**
+ * test for znodenames
+ */
+public class ZNodeNameTest extends TestCase {
+    @Test
+    public void testOrderWithSamePrefix() throws Exception {
+        String[] names = { "x-3", "x-5", "x-11", "x-1" };
+        String[] expected = { "x-1", "x-3", "x-5", "x-11" };
+        assertOrderedNodeNames(names, expected);
+    }
+    @Test
+    public void testOrderWithDifferentPrefixes() throws Exception {
+        String[] names = { "r-3", "r-2", "r-1", "w-2", "w-1" };
+        String[] expected = { "r-1", "w-1", "r-2", "w-2", "r-3" };
+        assertOrderedNodeNames(names, expected);
+    }
+    @Test
+    public void testOrderWithDifferentPrefixIncludingSessionId() throws Exception {
+        String[] names = { "x-242681582799028564-0000000002", "x-170623981976748329-0000000003", "x-98566387950223723-0000000001" };
+        String[] expected = { "x-98566387950223723-0000000001", "x-242681582799028564-0000000002", "x-170623981976748329-0000000003" };
+        assertOrderedNodeNames(names, expected);
+    }
+    @Test
+    public void testOrderWithExtraPrefixes() throws Exception {
+        String[] names = { "r-1-3-2", "r-2-2-1", "r-3-1-3" };
+        String[] expected = { "r-2-2-1", "r-1-3-2", "r-3-1-3" };
+        assertOrderedNodeNames(names, expected);
+    }
+
+    protected void assertOrderedNodeNames(String[] names, String[] expected) {
+        int size = names.length;
+        SortedSet<ZNodeName> nodeNames = new TreeSet<ZNodeName>();
+        for (String name : names) {
+            nodeNames.add(new ZNodeName(name));
+        }
+        assertEquals("The SortedSet does not have the expected size!", nodeNames.size(), expected.length);
+
+        int index = 0;
+        for (ZNodeName nodeName : nodeNames) {
+            String name = nodeName.getName();
+            assertEquals("Node " + index, expected[index++], name);
+        }
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/README.txt
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/README.txt b/zookeeper-recipes/queue/README.txt
new file mode 100644
index 0000000..d59a3c3
--- /dev/null
+++ b/zookeeper-recipes/queue/README.txt
@@ -0,0 +1,30 @@
+<!--
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+-->
+
+1) This queue interface recipe implements the queue recipe
+mentioned in ../../../docs/recipes.[html,pdf].
+A more detailed explanation is at http://www.cloudera.com/blog/2009/05/28/building-a-distributed-concurrent-queue-with-apache-zookeeper/
+
+2) This recipe does not handle KeeperException.ConnectionLossException or ZCONNECTIONLOSS. It will only work correctly once ZOOKEEPER-22 https://issues.apache.org/jira/browse/ZOOKEEPER-22 is resolved.
+
+3) To compile the queue java recipe you can just run ant jar from 
+this directory. 
+Please report any bugs on the jira 
+
+http://issues.apache.org/jira/browse/ZOOKEEPER
+
+  

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/build.xml
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/build.xml b/zookeeper-recipes/queue/build.xml
new file mode 100644
index 0000000..0f3505a
--- /dev/null
+++ b/zookeeper-recipes/queue/build.xml
@@ -0,0 +1,128 @@
+<!--
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+-->
+
+<project name="queue" default="jar">
+  <import file="../build-recipes.xml"/>
+    <property name="test.main.classes" value="${zk.root}/build/test/classes"/>
+    <property name="test.build.dir" value="${build.test}" />
+    <property name="test.src.dir" value="test"/>
+    <property name="test.log.dir" value="${test.build.dir}/logs" />
+    <property name="test.data.dir" value="${test.build.dir}/data" />
+    <property name="test.data.upgrade.dir" value="${test.data.dir}/upgrade" />
+    <property name="test.tmp.dir" value="${test.build.dir}/tmp" />
+    <property name="test.output" value="no" />
+    <property name="test.timeout" value="900000" />
+    <property name="test.junit.output.format" value="plain" />
+    <property name="test.junit.fork.mode" value="perTest" />
+    <property name="test.junit.printsummary" value="yes" />
+    <property name="test.junit.haltonfailure" value="no" />
+    <property name="test.junit.maxmem" value="512m" />
+
+  <target name="setjarname">
+    <property name="jarname"
+              value="${build.dir}/zookeeper-${version}-recipes-${name}.jar"/>
+  </target>
+
+  <!-- Override jar target to specify main class -->
+  <target name="jar" depends="checkMainCompiled, setjarname, compile">
+    <echo message="recipes: ${name}"/>
+
+    <jar jarfile="${jarname}">
+      <fileset file="${zk.root}/LICENSE.txt" />
+      <fileset dir="${build.classes}"/>
+      <fileset dir="${build.test}"/>
+    </jar>
+  </target>
+
+	<target name="test" depends="compile-test,test-init,test-category,junit.run" />
+
+	<target name="compile-test" depends="compile">
+  		<property name="target.jdk" value="${ant.java.version}" />	
+		<property name="src.test.local" location="${basedir}/test" />
+		<mkdir dir="${build.test}"/>
+		<javac srcdir="${src.test.local}" 
+			destdir="${build.test}" 
+			target="${target.jdk}" 
+			debug="on" >
+			<classpath refid="classpath" />
+                        <classpath>
+                        <pathelement path="${test.main.classes}"/>
+                        </classpath>
+		</javac>
+	</target>
+	
+    <target name="test-init" depends="jar,compile-test">
+        <delete dir="${test.log.dir}" />
+        <delete dir="${test.tmp.dir}" />
+        <delete dir="${test.data.dir}" />
+        <mkdir dir="${test.log.dir}" />
+        <mkdir dir="${test.tmp.dir}" />
+        <mkdir dir="${test.data.dir}" />
+    </target>
+
+	<target name="test-category">
+         <property name="test.category" value=""/>
+    </target>
+
+	<target name="junit.run">
+		<echo message="${test.src.dir}" />
+        <junit showoutput="${test.output}"
+               printsummary="${test.junit.printsummary}"
+               haltonfailure="${test.junit.haltonfailure}"
+               fork="yes"
+               forkmode="${test.junit.fork.mode}"
+               maxmemory="${test.junit.maxmem}"
+               dir="${basedir}" timeout="${test.timeout}"
+               errorProperty="tests.failed" failureProperty="tests.failed">
+          <sysproperty key="build.test.dir" value="${test.tmp.dir}" />
+          <sysproperty key="test.data.dir" value="${test.data.dir}" />
+          <sysproperty key="log4j.configuration"
+                    value="file:${basedir}/conf/log4j.properties" />
+          <classpath refid="classpath"/>
+          <classpath>
+             <pathelement path="${build.test}" />
+             <pathelement path="${test.main.classes}"/>
+          </classpath>
+          <formatter type="${test.junit.output.format}" />
+          <batchtest todir="${test.log.dir}" unless="testcase">
+              <fileset dir="${test.src.dir}"
+                     includes="**/*${test.category}Test.java"/>
+          </batchtest>
+          <batchtest todir="${test.log.dir}" if="testcase">
+              <fileset dir="${test.src.dir}" includes="**/${testcase}.java"/>
+          </batchtest>
+       </junit>
+            <fail if="tests.failed">Tests failed!</fail>
+    </target>
+
+  <target name="package" depends="jar, zookeeperbuildrecipes.package"
+          unless="skip.recipes">
+
+    <copy file="${basedir}/build.xml" todir="${dist.dir}${package.share}/recipes/${name}"/>
+
+    <mkdir dir="${dist.dir}${package.share}/recipes/${name}/test"/>
+    <copy todir="${dist.dir}${package.share}/recipes/${name}/test">
+      <fileset dir="${basedir}/test"/>
+    </copy>
+    <mkdir dir="${dist.dir}${package.share}/recipes/${name}/src"/>
+    <copy todir="${dist.dir}${package.share}/recipes/${name}/src">
+      <fileset dir="${basedir}/src"/>
+    </copy>
+  </target>
+
+</project>
+

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/src/c/INSTALL
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/src/c/INSTALL b/zookeeper-recipes/queue/src/c/INSTALL
new file mode 100644
index 0000000..5458714
--- /dev/null
+++ b/zookeeper-recipes/queue/src/c/INSTALL
@@ -0,0 +1,234 @@
+Installation Instructions
+*************************
+
+Copyright (C) 1994, 1995, 1996, 1999, 2000, 2001, 2002, 2004, 2005,
+2006 Free Software Foundation, Inc.
+
+This file is free documentation; the Free Software Foundation gives
+unlimited permission to copy, distribute and modify it.
+
+Basic Installation
+==================
+
+Briefly, the shell commands `./configure; make; make install' should
+configure, build, and install this package.  The following
+more-detailed instructions are generic; see the `README' file for
+instructions specific to this package.
+
+   The `configure' shell script attempts to guess correct values for
+various system-dependent variables used during compilation.  It uses
+those values to create a `Makefile' in each directory of the package.
+It may also create one or more `.h' files containing system-dependent
+definitions.  Finally, it creates a shell script `config.status' that
+you can run in the future to recreate the current configuration, and a
+file `config.log' containing compiler output (useful mainly for
+debugging `configure').
+
+   It can also use an optional file (typically called `config.cache'
+and enabled with `--cache-file=config.cache' or simply `-C') that saves
+the results of its tests to speed up reconfiguring.  Caching is
+disabled by default to prevent problems with accidental use of stale
+cache files.
+
+   If you need to do unusual things to compile the package, please try
+to figure out how `configure' could check whether to do them, and mail
+diffs or instructions to the address given in the `README' so they can
+be considered for the next release.  If you are using the cache, and at
+some point `config.cache' contains results you don't want to keep, you
+may remove or edit it.
+
+   The file `configure.ac' (or `configure.in') is used to create
+`configure' by a program called `autoconf'.  You need `configure.ac' if
+you want to change it or regenerate `configure' using a newer version
+of `autoconf'.
+
+The simplest way to compile this package is:
+
+  1. `cd' to the directory containing the package's source code and type
+     `./configure' to configure the package for your system.
+
+     Running `configure' might take a while.  While running, it prints
+     some messages telling which features it is checking for.
+
+  2. Type `make' to compile the package.
+
+  3. Optionally, type `make check' to run any self-tests that come with
+     the package.
+
+  4. Type `make install' to install the programs and any data files and
+     documentation.
+
+  5. You can remove the program binaries and object files from the
+     source code directory by typing `make clean'.  To also remove the
+     files that `configure' created (so you can compile the package for
+     a different kind of computer), type `make distclean'.  There is
+     also a `make maintainer-clean' target, but that is intended mainly
+     for the package's developers.  If you use it, you may have to get
+     all sorts of other programs in order to regenerate files that came
+     with the distribution.
+
+Compilers and Options
+=====================
+
+Some systems require unusual options for compilation or linking that the
+`configure' script does not know about.  Run `./configure --help' for
+details on some of the pertinent environment variables.
+
+   You can give `configure' initial values for configuration parameters
+by setting variables in the command line or in the environment.  Here
+is an example:
+
+     ./configure CC=c99 CFLAGS=-g LIBS=-lposix
+
+   *Note Defining Variables::, for more details.
+
+Compiling For Multiple Architectures
+====================================
+
+You can compile the package for more than one kind of computer at the
+same time, by placing the object files for each architecture in their
+own directory.  To do this, you can use GNU `make'.  `cd' to the
+directory where you want the object files and executables to go and run
+the `configure' script.  `configure' automatically checks for the
+source code in the directory that `configure' is in and in `..'.
+
+   With a non-GNU `make', it is safer to compile the package for one
+architecture at a time in the source code directory.  After you have
+installed the package for one architecture, use `make distclean' before
+reconfiguring for another architecture.
+
+Installation Names
+==================
+
+By default, `make install' installs the package's commands under
+`/usr/local/bin', include files under `/usr/local/include', etc.  You
+can specify an installation prefix other than `/usr/local' by giving
+`configure' the option `--prefix=PREFIX'.
+
+   You can specify separate installation prefixes for
+architecture-specific files and architecture-independent files.  If you
+pass the option `--exec-prefix=PREFIX' to `configure', the package uses
+PREFIX as the prefix for installing programs and libraries.
+Documentation and other data files still use the regular prefix.
+
+   In addition, if you use an unusual directory layout you can give
+options like `--bindir=DIR' to specify different values for particular
+kinds of files.  Run `configure --help' for a list of the directories
+you can set and what kinds of files go in them.
+
+   If the package supports it, you can cause programs to be installed
+with an extra prefix or suffix on their names by giving `configure' the
+option `--program-prefix=PREFIX' or `--program-suffix=SUFFIX'.
+
+Optional Features
+=================
+
+Some packages pay attention to `--enable-FEATURE' options to
+`configure', where FEATURE indicates an optional part of the package.
+They may also pay attention to `--with-PACKAGE' options, where PACKAGE
+is something like `gnu-as' or `x' (for the X Window System).  The
+`README' should mention any `--enable-' and `--with-' options that the
+package recognizes.
+
+   For packages that use the X Window System, `configure' can usually
+find the X include and library files automatically, but if it doesn't,
+you can use the `configure' options `--x-includes=DIR' and
+`--x-libraries=DIR' to specify their locations.
+
+Specifying the System Type
+==========================
+
+There may be some features `configure' cannot figure out automatically,
+but needs to determine by the type of machine the package will run on.
+Usually, assuming the package is built to be run on the _same_
+architectures, `configure' can figure that out, but if it prints a
+message saying it cannot guess the machine type, give it the
+`--build=TYPE' option.  TYPE can either be a short name for the system
+type, such as `sun4', or a canonical name which has the form:
+
+     CPU-COMPANY-SYSTEM
+
+where SYSTEM can have one of these forms:
+
+     OS KERNEL-OS
+
+   See the file `config.sub' for the possible values of each field.  If
+`config.sub' isn't included in this package, then this package doesn't
+need to know the machine type.
+
+   If you are _building_ compiler tools for cross-compiling, you should
+use the option `--target=TYPE' to select the type of system they will
+produce code for.
+
+   If you want to _use_ a cross compiler, that generates code for a
+platform different from the build platform, you should specify the
+"host" platform (i.e., that on which the generated programs will
+eventually be run) with `--host=TYPE'.
+
+Sharing Defaults
+================
+
+If you want to set default values for `configure' scripts to share, you
+can create a site shell script called `config.site' that gives default
+values for variables like `CC', `cache_file', and `prefix'.
+`configure' looks for `PREFIX/share/config.site' if it exists, then
+`PREFIX/etc/config.site' if it exists.  Or, you can set the
+`CONFIG_SITE' environment variable to the location of the site script.
+A warning: not all `configure' scripts look for a site script.
+
+Defining Variables
+==================
+
+Variables not defined in a site shell script can be set in the
+environment passed to `configure'.  However, some packages may run
+configure again during the build, and the customized values of these
+variables may be lost.  In order to avoid this problem, you should set
+them in the `configure' command line, using `VAR=value'.  For example:
+
+     ./configure CC=/usr/local2/bin/gcc
+
+causes the specified `gcc' to be used as the C compiler (unless it is
+overridden in the site shell script).
+
+Unfortunately, this technique does not work for `CONFIG_SHELL' due to
+an Autoconf bug.  Until the bug is fixed you can use this workaround:
+
+     CONFIG_SHELL=/bin/bash /bin/bash ./configure CONFIG_SHELL=/bin/bash
+
+`configure' Invocation
+======================
+
+`configure' recognizes the following options to control how it operates.
+
+`--help'
+`-h'
+     Print a summary of the options to `configure', and exit.
+
+`--version'
+`-V'
+     Print the version of Autoconf used to generate the `configure'
+     script, and exit.
+
+`--cache-file=FILE'
+     Enable the cache: use and save the results of the tests in FILE,
+     traditionally `config.cache'.  FILE defaults to `/dev/null' to
+     disable caching.
+
+`--config-cache'
+`-C'
+     Alias for `--cache-file=config.cache'.
+
+`--quiet'
+`--silent'
+`-q'
+     Do not print messages saying which checks are being made.  To
+     suppress all normal output, redirect it to `/dev/null' (any error
+     messages will still be shown).
+
+`--srcdir=DIR'
+     Look for the package's source code in directory DIR.  Usually
+     `configure' can determine that directory automatically.
+
+`configure' also accepts some other, not widely useful, options.  Run
+`configure --help' for more details.
+

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/src/c/LICENSE
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/src/c/LICENSE b/zookeeper-recipes/queue/src/c/LICENSE
new file mode 100644
index 0000000..d645695
--- /dev/null
+++ b/zookeeper-recipes/queue/src/c/LICENSE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
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+      direction or management of such entity, whether by contract or
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+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
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+   6. Trademarks. This License does not grant permission to use the trade
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+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      has been advised of the possibility of such damages.
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+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
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+      file or class name and description of purpose be included on the
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+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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+   limitations under the License.

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/src/c/Makefile.am
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/src/c/Makefile.am b/zookeeper-recipes/queue/src/c/Makefile.am
new file mode 100644
index 0000000..ecef3cc
--- /dev/null
+++ b/zookeeper-recipes/queue/src/c/Makefile.am
@@ -0,0 +1,46 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+include $(top_srcdir)/aminclude.am
+
+AM_CFLAGS = -Wall -fPIC -I${ZOOKEEPER_PATH}/include -I${ZOOKEEPER_PATH}/generated \
+  -I$(top_srcdir)/include -I/usr/include 
+AM_CPPFLAGS = -Wall -I${ZOOKEEPER_PATH}/include -I${ZOOKEEPER_PATH}/generated\
+  -I${top_srcdir}/include -I/usr/include
+EXTRA_DIST = LICENSE
+lib_LTLIBRARIES = libzooqueue.la
+libzooqueue_la_SOURCES = src/zoo_queue.c include/zoo_queue.h
+libzooqueue_la_CPPFLAGS = -DDLOPEN_MODULE
+libzooqueue_la_LDFLAGS = -version-info 0:1:0
+
+#run the tests now
+
+TEST_SOURCES = tests/TestDriver.cc tests/TestClient.cc tests/Util.cc 
+
+
+check_PROGRAMS = zkqueuetest
+nodist_zkqueuetest_SOURCES = ${TEST_SOURCES}
+zkqueuetest_LDADD =  ${ZOOKEEPER_LD} libzooqueue.la -lpthread  ${CPPUNIT_LIBS}
+zkqueuetest_CXXFLAGS = -DUSE_STATIC_LIB ${CPPUNIT_CFLAGS}
+
+run-check: check
+	./zkqueuetest ${TEST_OPTIONS}
+
+clean-local: clean-check
+	${RM} ${DX_CLEANFILES}
+
+clean-check:
+	${RM} ${nodist_zkqueuetest_OBJECTS} 

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/src/c/README.txt
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/src/c/README.txt b/zookeeper-recipes/queue/src/c/README.txt
new file mode 100644
index 0000000..7ef253f
--- /dev/null
+++ b/zookeeper-recipes/queue/src/c/README.txt
@@ -0,0 +1,30 @@
+                     Zookeeper C queue client library 
+
+
+INSTALLATION
+
+If you're building the client from a source checkout you need to
+follow the steps outlined below. If you're building from a release
+tar downloaded from Apache please skip to step 2.
+
+This recipe does not handle ZCONNECTIONLOSS. It will only work correctly once ZOOKEEPER-22 https://issues.apache.org/jira/browse/ZOOKEEPER-22 is resolved.
+
+1) make sure that you compile the main zookeeper c client library.
+ 
+2) change directory to src/recipes/queue/src/c 
+    and do a "autoreconf -if" to bootstrap
+   autoconf, automake and libtool. Please make sure you have autoconf
+   version 2.59 or greater installed.
+3) do a "./configure [OPTIONS]" to generate the makefile. See INSTALL
+   for general information about running configure.
+
+4) do a "make" or "make install" to build the libraries and install them. 
+   Alternatively, you can also build and run a unit test suite (and
+   you probably should).  Please make sure you have cppunit-1.10.x or
+   higher installed before you execute step 4.  Once ./configure has
+   finished, do a "make run-check". It will build the libraries, build
+   the tests and run them.
+5) to generate doxygen documentation do a "make doxygen-doc". All
+   documentations will be placed to a new subfolder named docs. By
+   default only HTML documentation is generated.  For information on
+   other document formats please use "./configure --help"

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/src/c/acinclude.m4
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/src/c/acinclude.m4 b/zookeeper-recipes/queue/src/c/acinclude.m4
new file mode 100644
index 0000000..d0041d8
--- /dev/null
+++ b/zookeeper-recipes/queue/src/c/acinclude.m4
@@ -0,0 +1,312 @@
+# This file is part of Autoconf.                       -*- Autoconf -*-
+
+# Copyright (C) 2004 Oren Ben-Kiki
+# This file is distributed under the same terms as the Autoconf macro files.
+
+# Generate automatic documentation using Doxygen. Works in concert with the
+# aminclude.m4 file and a compatible doxygen configuration file. Defines the
+# following public macros:
+#
+# DX_???_FEATURE(ON|OFF) - control the default setting fo a Doxygen feature.
+# Supported features are 'DOXYGEN' itself, 'DOT' for generating graphics,
+# 'HTML' for plain HTML, 'CHM' for compressed HTML help (for MS users), 'CHI'
+# for generating a seperate .chi file by the .chm file, and 'MAN', 'RTF',
+# 'XML', 'PDF' and 'PS' for the appropriate output formats. The environment
+# variable DOXYGEN_PAPER_SIZE may be specified to override the default 'a4wide'
+# paper size.
+#
+# By default, HTML, PDF and PS documentation is generated as this seems to be
+# the most popular and portable combination. MAN pages created by Doxygen are
+# usually problematic, though by picking an appropriate subset and doing some
+# massaging they might be better than nothing. CHM and RTF are specific for MS
+# (note that you can't generate both HTML and CHM at the same time). The XML is
+# rather useless unless you apply specialized post-processing to it.
+#
+# The macro mainly controls the default state of the feature. The use can
+# override the default by specifying --enable or --disable. The macros ensure
+# that contradictory flags are not given (e.g., --enable-doxygen-html and
+# --enable-doxygen-chm, --enable-doxygen-anything with --disable-doxygen, etc.)
+# Finally, each feature will be automatically disabled (with a warning) if the
+# required programs are missing.
+#
+# Once all the feature defaults have been specified, call DX_INIT_DOXYGEN with
+# the following parameters: a one-word name for the project for use as a
+# filename base etc., an optional configuration file name (the default is
+# 'Doxyfile', the same as Doxygen's default), and an optional output directory
+# name (the default is 'doxygen-doc').
+
+## ----------##
+## Defaults. ##
+## ----------##
+
+DX_ENV=""
+AC_DEFUN([DX_FEATURE_doc],  ON)
+AC_DEFUN([DX_FEATURE_dot],  ON)
+AC_DEFUN([DX_FEATURE_man],  OFF)
+AC_DEFUN([DX_FEATURE_html], ON)
+AC_DEFUN([DX_FEATURE_chm],  OFF)
+AC_DEFUN([DX_FEATURE_chi],  OFF)
+AC_DEFUN([DX_FEATURE_rtf],  OFF)
+AC_DEFUN([DX_FEATURE_xml],  OFF)
+AC_DEFUN([DX_FEATURE_pdf],  ON)
+AC_DEFUN([DX_FEATURE_ps],   ON)
+
+## --------------- ##
+## Private macros. ##
+## --------------- ##
+
+# DX_ENV_APPEND(VARIABLE, VALUE)
+# ------------------------------
+# Append VARIABLE="VALUE" to DX_ENV for invoking doxygen.
+AC_DEFUN([DX_ENV_APPEND], [AC_SUBST([DX_ENV], ["$DX_ENV $1='$2'"])])
+
+# DX_DIRNAME_EXPR
+# ---------------
+# Expand into a shell expression prints the directory part of a path.
+AC_DEFUN([DX_DIRNAME_EXPR],
+         [[expr ".$1" : '\(\.\)[^/]*$' \| "x$1" : 'x\(.*\)/[^/]*$']])
+
+# DX_IF_FEATURE(FEATURE, IF-ON, IF-OFF)
+# -------------------------------------
+# Expands according to the M4 (static) status of the feature.
+AC_DEFUN([DX_IF_FEATURE], [ifelse(DX_FEATURE_$1, ON, [$2], [$3])])
+
+# DX_REQUIRE_PROG(VARIABLE, PROGRAM)
+# ----------------------------------
+# Require the specified program to be found for the DX_CURRENT_FEATURE to work.
+AC_DEFUN([DX_REQUIRE_PROG], [
+AC_PATH_TOOL([$1], [$2])
+if test "$DX_FLAG_$[DX_CURRENT_FEATURE$$1]" = 1; then
+    AC_MSG_WARN([$2 not found - will not DX_CURRENT_DESCRIPTION])
+    AC_SUBST([DX_FLAG_]DX_CURRENT_FEATURE, 0)
+fi
+])
+
+# DX_TEST_FEATURE(FEATURE)
+# ------------------------
+# Expand to a shell expression testing whether the feature is active.
+AC_DEFUN([DX_TEST_FEATURE], [test "$DX_FLAG_$1" = 1])
+
+# DX_CHECK_DEPEND(REQUIRED_FEATURE, REQUIRED_STATE)
+# -------------------------------------------------
+# Verify that a required features has the right state before trying to turn on
+# the DX_CURRENT_FEATURE.
+AC_DEFUN([DX_CHECK_DEPEND], [
+test "$DX_FLAG_$1" = "$2" \
+|| AC_MSG_ERROR([doxygen-DX_CURRENT_FEATURE ifelse([$2], 1,
+                            requires, contradicts) doxygen-DX_CURRENT_FEATURE])
+])
+
+# DX_CLEAR_DEPEND(FEATURE, REQUIRED_FEATURE, REQUIRED_STATE)
+# ----------------------------------------------------------
+# Turn off the DX_CURRENT_FEATURE if the required feature is off.
+AC_DEFUN([DX_CLEAR_DEPEND], [
+test "$DX_FLAG_$1" = "$2" || AC_SUBST([DX_FLAG_]DX_CURRENT_FEATURE, 0)
+])
+
+# DX_FEATURE_ARG(FEATURE, DESCRIPTION,
+#                CHECK_DEPEND, CLEAR_DEPEND,
+#                REQUIRE, DO-IF-ON, DO-IF-OFF)
+# --------------------------------------------
+# Parse the command-line option controlling a feature. CHECK_DEPEND is called
+# if the user explicitly turns the feature on (and invokes DX_CHECK_DEPEND),
+# otherwise CLEAR_DEPEND is called to turn off the default state if a required
+# feature is disabled (using DX_CLEAR_DEPEND). REQUIRE performs additional
+# requirement tests (DX_REQUIRE_PROG). Finally, an automake flag is set and
+# DO-IF-ON or DO-IF-OFF are called according to the final state of the feature.
+AC_DEFUN([DX_ARG_ABLE], [
+    AC_DEFUN([DX_CURRENT_FEATURE], [$1])
+    AC_DEFUN([DX_CURRENT_DESCRIPTION], [$2])
+    AC_ARG_ENABLE(doxygen-$1,
+                  [AS_HELP_STRING(DX_IF_FEATURE([$1], [--disable-doxygen-$1],
+                                                      [--enable-doxygen-$1]),
+                                  DX_IF_FEATURE([$1], [don't $2], [$2]))],
+                  [
+case "$enableval" in
+#(
+y|Y|yes|Yes|YES)
+    AC_SUBST([DX_FLAG_$1], 1)
+    $3
+;; #(
+n|N|no|No|NO)
+    AC_SUBST([DX_FLAG_$1], 0)
+;; #(
+*)
+    AC_MSG_ERROR([invalid value '$enableval' given to doxygen-$1])
+;;
+esac
+], [
+AC_SUBST([DX_FLAG_$1], [DX_IF_FEATURE([$1], 1, 0)])
+$4
+])
+if DX_TEST_FEATURE([$1]); then
+    $5
+    :
+fi
+if DX_TEST_FEATURE([$1]); then
+    AM_CONDITIONAL(DX_COND_$1, :)
+    $6
+    :
+else
+    AM_CONDITIONAL(DX_COND_$1, false)
+    $7
+    :
+fi
+])
+
+## -------------- ##
+## Public macros. ##
+## -------------- ##
+
+# DX_XXX_FEATURE(DEFAULT_STATE)
+# -----------------------------
+AC_DEFUN([DX_DOXYGEN_FEATURE], [AC_DEFUN([DX_FEATURE_doc],  [$1])])
+AC_DEFUN([DX_MAN_FEATURE],     [AC_DEFUN([DX_FEATURE_man],  [$1])])
+AC_DEFUN([DX_HTML_FEATURE],    [AC_DEFUN([DX_FEATURE_html], [$1])])
+AC_DEFUN([DX_CHM_FEATURE],     [AC_DEFUN([DX_FEATURE_chm],  [$1])])
+AC_DEFUN([DX_CHI_FEATURE],     [AC_DEFUN([DX_FEATURE_chi],  [$1])])
+AC_DEFUN([DX_RTF_FEATURE],     [AC_DEFUN([DX_FEATURE_rtf],  [$1])])
+AC_DEFUN([DX_XML_FEATURE],     [AC_DEFUN([DX_FEATURE_xml],  [$1])])
+AC_DEFUN([DX_XML_FEATURE],     [AC_DEFUN([DX_FEATURE_xml],  [$1])])
+AC_DEFUN([DX_PDF_FEATURE],     [AC_DEFUN([DX_FEATURE_pdf],  [$1])])
+AC_DEFUN([DX_PS_FEATURE],      [AC_DEFUN([DX_FEATURE_ps],   [$1])])
+
+# DX_INIT_DOXYGEN(PROJECT, [CONFIG-FILE], [OUTPUT-DOC-DIR])
+# ---------------------------------------------------------
+# PROJECT also serves as the base name for the documentation files.
+# The default CONFIG-FILE is "Doxyfile" and OUTPUT-DOC-DIR is "doxygen-doc".
+AC_DEFUN([DX_INIT_DOXYGEN], [
+
+# Files:
+AC_SUBST([DX_PROJECT], [$1])
+AC_SUBST([DX_CONFIG], [ifelse([$2], [], Doxyfile, [$2])])
+AC_SUBST([DX_DOCDIR], [ifelse([$3], [], doxygen-doc, [$3])])
+
+# Environment variables used inside doxygen.cfg:
+DX_ENV_APPEND(SRCDIR, $srcdir)
+DX_ENV_APPEND(PROJECT, $DX_PROJECT)
+DX_ENV_APPEND(DOCDIR, $DX_DOCDIR)
+DX_ENV_APPEND(VERSION, $PACKAGE_VERSION)
+
+# Doxygen itself:
+DX_ARG_ABLE(doc, [generate any doxygen documentation],
+            [],
+            [],
+            [DX_REQUIRE_PROG([DX_DOXYGEN], doxygen)
+             DX_REQUIRE_PROG([DX_PERL], perl)],
+            [DX_ENV_APPEND(PERL_PATH, $DX_PERL)])
+
+# Dot for graphics:
+DX_ARG_ABLE(dot, [generate graphics for doxygen documentation],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [DX_REQUIRE_PROG([DX_DOT], dot)],
+            [DX_ENV_APPEND(HAVE_DOT, YES)
+             DX_ENV_APPEND(DOT_PATH, [`DX_DIRNAME_EXPR($DX_DOT)`])],
+            [DX_ENV_APPEND(HAVE_DOT, NO)])
+
+# Man pages generation:
+DX_ARG_ABLE(man, [generate doxygen manual pages],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [],
+            [DX_ENV_APPEND(GENERATE_MAN, YES)],
+            [DX_ENV_APPEND(GENERATE_MAN, NO)])
+
+# RTF file generation:
+DX_ARG_ABLE(rtf, [generate doxygen RTF documentation],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [],
+            [DX_ENV_APPEND(GENERATE_RTF, YES)],
+            [DX_ENV_APPEND(GENERATE_RTF, NO)])
+
+# XML file generation:
+DX_ARG_ABLE(xml, [generate doxygen XML documentation],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [],
+            [DX_ENV_APPEND(GENERATE_XML, YES)],
+            [DX_ENV_APPEND(GENERATE_XML, NO)])
+
+# (Compressed) HTML help generation:
+DX_ARG_ABLE(chm, [generate doxygen compressed HTML help documentation],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [DX_REQUIRE_PROG([DX_HHC], hhc)],
+            [DX_ENV_APPEND(HHC_PATH, $DX_HHC)
+             DX_ENV_APPEND(GENERATE_HTML, YES)
+             DX_ENV_APPEND(GENERATE_HTMLHELP, YES)],
+            [DX_ENV_APPEND(GENERATE_HTMLHELP, NO)])
+
+# Seperate CHI file generation.
+DX_ARG_ABLE(chi, [generate doxygen seperate compressed HTML help index file],
+            [DX_CHECK_DEPEND(chm, 1)],
+            [DX_CLEAR_DEPEND(chm, 1)],
+            [],
+            [DX_ENV_APPEND(GENERATE_CHI, YES)],
+            [DX_ENV_APPEND(GENERATE_CHI, NO)])
+
+# Plain HTML pages generation:
+DX_ARG_ABLE(html, [generate doxygen plain HTML documentation],
+            [DX_CHECK_DEPEND(doc, 1) DX_CHECK_DEPEND(chm, 0)],
+            [DX_CLEAR_DEPEND(doc, 1) DX_CLEAR_DEPEND(chm, 0)],
+            [],
+            [DX_ENV_APPEND(GENERATE_HTML, YES)],
+            [DX_TEST_FEATURE(chm) || DX_ENV_APPEND(GENERATE_HTML, NO)])
+
+# PostScript file generation:
+DX_ARG_ABLE(ps, [generate doxygen PostScript documentation],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [DX_REQUIRE_PROG([DX_LATEX], latex)
+             DX_REQUIRE_PROG([DX_MAKEINDEX], makeindex)
+             DX_REQUIRE_PROG([DX_DVIPS], dvips)
+             DX_REQUIRE_PROG([DX_EGREP], egrep)])
+
+# PDF file generation:
+DX_ARG_ABLE(pdf, [generate doxygen PDF documentation],
+            [DX_CHECK_DEPEND(doc, 1)],
+            [DX_CLEAR_DEPEND(doc, 1)],
+            [DX_REQUIRE_PROG([DX_PDFLATEX], pdflatex)
+             DX_REQUIRE_PROG([DX_MAKEINDEX], makeindex)
+             DX_REQUIRE_PROG([DX_EGREP], egrep)])
+
+# LaTeX generation for PS and/or PDF:
+if DX_TEST_FEATURE(ps) || DX_TEST_FEATURE(pdf); then
+    AM_CONDITIONAL(DX_COND_latex, :)
+    DX_ENV_APPEND(GENERATE_LATEX, YES)
+else
+    AM_CONDITIONAL(DX_COND_latex, false)
+    DX_ENV_APPEND(GENERATE_LATEX, NO)
+fi
+
+# Paper size for PS and/or PDF:
+AC_ARG_VAR(DOXYGEN_PAPER_SIZE,
+           [a4wide (default), a4, letter, legal or executive])
+case "$DOXYGEN_PAPER_SIZE" in
+#(
+"")
+    AC_SUBST(DOXYGEN_PAPER_SIZE, "")
+;; #(
+a4wide|a4|letter|legal|executive)
+    DX_ENV_APPEND(PAPER_SIZE, $DOXYGEN_PAPER_SIZE)
+;; #(
+*)
+    AC_MSG_ERROR([unknown DOXYGEN_PAPER_SIZE='$DOXYGEN_PAPER_SIZE'])
+;;
+esac
+
+#For debugging:
+#echo DX_FLAG_doc=$DX_FLAG_doc
+#echo DX_FLAG_dot=$DX_FLAG_dot
+#echo DX_FLAG_man=$DX_FLAG_man
+#echo DX_FLAG_html=$DX_FLAG_html
+#echo DX_FLAG_chm=$DX_FLAG_chm
+#echo DX_FLAG_chi=$DX_FLAG_chi
+#echo DX_FLAG_rtf=$DX_FLAG_rtf
+#echo DX_FLAG_xml=$DX_FLAG_xml
+#echo DX_FLAG_pdf=$DX_FLAG_pdf
+#echo DX_FLAG_ps=$DX_FLAG_ps
+#echo DX_ENV=$DX_ENV
+])

http://git-wip-us.apache.org/repos/asf/zookeeper/blob/e5b4b94d/zookeeper-recipes/queue/src/c/aminclude.am
----------------------------------------------------------------------
diff --git a/zookeeper-recipes/queue/src/c/aminclude.am b/zookeeper-recipes/queue/src/c/aminclude.am
new file mode 100644
index 0000000..420049e
--- /dev/null
+++ b/zookeeper-recipes/queue/src/c/aminclude.am
@@ -0,0 +1,186 @@
+# Copyright (C) 2004 Oren Ben-Kiki
+# This file is distributed under the same terms as the Automake macro files.
+
+# Generate automatic documentation using Doxygen. Goals and variables values
+# are controlled by the various DX_COND_??? conditionals set by autoconf.
+#
+# The provided goals are:
+# doxygen-doc: Generate all doxygen documentation.
+# doxygen-run: Run doxygen, which will generate some of the documentation
+#              (HTML, CHM, CHI, MAN, RTF, XML) but will not do the post
+#              processing required for the rest of it (PS, PDF, and some MAN).
+# doxygen-man: Rename some doxygen generated man pages.
+# doxygen-ps: Generate doxygen PostScript documentation.
+# doxygen-pdf: Generate doxygen PDF documentation.
+#
+# Note that by default these are not integrated into the automake goals. If
+# doxygen is used to generate man pages, you can achieve this integration by
+# setting man3_MANS to the list of man pages generated and then adding the
+# dependency:
+#
+#   $(man3_MANS): doxygen-doc
+#
+# This will cause make to run doxygen and generate all the documentation.
+#
+# The following variable is intended for use in Makefile.am:
+#
+# DX_CLEANFILES = everything to clean.
+#
+# This is usually added to MOSTLYCLEANFILES.
+
+## --------------------------------- ##
+## Format-independent Doxygen rules. ##
+## --------------------------------- ##
+
+if DX_COND_doc
+
+## ------------------------------- ##
+## Rules specific for HTML output. ##
+## ------------------------------- ##
+
+if DX_COND_html
+
+DX_CLEAN_HTML = @DX_DOCDIR@/html
+
+endif DX_COND_html
+
+## ------------------------------ ##
+## Rules specific for CHM output. ##
+## ------------------------------ ##
+
+if DX_COND_chm
+
+DX_CLEAN_CHM = @DX_DOCDIR@/chm
+
+if DX_COND_chi
+
+DX_CLEAN_CHI = @DX_DOCDIR@/@PACKAGE@.chi
+
+endif DX_COND_chi
+
+endif DX_COND_chm
+
+## ------------------------------ ##
+## Rules specific for MAN output. ##
+## ------------------------------ ##
+
+if DX_COND_man
+
+DX_CLEAN_MAN = @DX_DOCDIR@/man
+
+endif DX_COND_man
+
+## ------------------------------ ##
+## Rules specific for RTF output. ##
+## ------------------------------ ##
+
+if DX_COND_rtf
+
+DX_CLEAN_RTF = @DX_DOCDIR@/rtf
+
+endif DX_COND_rtf
+
+## ------------------------------ ##
+## Rules specific for XML output. ##
+## ------------------------------ ##
+
+if DX_COND_xml
+
+DX_CLEAN_XML = @DX_DOCDIR@/xml
+
+endif DX_COND_xml
+
+## ----------------------------- ##
+## Rules specific for PS output. ##
+## ----------------------------- ##
+
+if DX_COND_ps
+
+DX_CLEAN_PS = @DX_DOCDIR@/@PACKAGE@.ps
+
+DX_PS_GOAL = doxygen-ps
+
+doxygen-ps: @DX_DOCDIR@/@PACKAGE@.ps
+
+@DX_DOCDIR@/@PACKAGE@.ps: @DX_DOCDIR@/@PACKAGE@.tag
+	cd @DX_DOCDIR@/latex; \
+	rm -f *.aux *.toc *.idx *.ind *.ilg *.log *.out; \
+	$(DX_LATEX) refman.tex; \
+	$(MAKEINDEX_PATH) refman.idx; \
+	$(DX_LATEX) refman.tex; \
+	countdown=5; \
+	while $(DX_EGREP) 'Rerun (LaTeX|to get cross-references right)' \
+	                  refman.log > /dev/null 2>&1 \
+	   && test $$countdown -gt 0; do \
+	    $(DX_LATEX) refman.tex; \
+	    countdown=`expr $$countdown - 1`; \
+	done; \
+	$(DX_DVIPS) -o ../@PACKAGE@.ps refman.dvi
+
+endif DX_COND_ps
+
+## ------------------------------ ##
+## Rules specific for PDF output. ##
+## ------------------------------ ##
+
+if DX_COND_pdf
+
+DX_CLEAN_PDF = @DX_DOCDIR@/@PACKAGE@.pdf
+
+DX_PDF_GOAL = doxygen-pdf
+
+doxygen-pdf: @DX_DOCDIR@/@PACKAGE@.pdf
+
+@DX_DOCDIR@/@PACKAGE@.pdf: @DX_DOCDIR@/@PACKAGE@.tag
+	cd @DX_DOCDIR@/latex; \
+	rm -f *.aux *.toc *.idx *.ind *.ilg *.log *.out; \
+	$(DX_PDFLATEX) refman.tex; \
+	$(DX_MAKEINDEX) refman.idx; \
+	$(DX_PDFLATEX) refman.tex; \
+	countdown=5; \
+	while $(DX_EGREP) 'Rerun (LaTeX|to get cross-references right)' \
+	                  refman.log > /dev/null 2>&1 \
+	   && test $$countdown -gt 0; do \
+	    $(DX_PDFLATEX) refman.tex; \
+	    countdown=`expr $$countdown - 1`; \
+	done; \
+	mv refman.pdf ../@PACKAGE@.pdf
+
+endif DX_COND_pdf
+
+## ------------------------------------------------- ##
+## Rules specific for LaTeX (shared for PS and PDF). ##
+## ------------------------------------------------- ##
+
+if DX_COND_latex
+
+DX_CLEAN_LATEX = @DX_DOCDIR@/latex
+
+endif DX_COND_latex
+
+.PHONY: doxygen-run doxygen-doc $(DX_PS_GOAL) $(DX_PDF_GOAL)
+
+.INTERMEDIATE: doxygen-run $(DX_PS_GOAL) $(DX_PDF_GOAL)
+
+doxygen-run: @DX_DOCDIR@/@PACKAGE@.tag
+
+doxygen-doc: doxygen-run $(DX_PS_GOAL) $(DX_PDF_GOAL)
+
+@DX_DOCDIR@/@PACKAGE@.tag: $(DX_CONFIG) $(pkginclude_HEADERS)
+	rm -rf @DX_DOCDIR@
+	$(DX_ENV) $(DX_DOXYGEN) $(srcdir)/$(DX_CONFIG)
+
+DX_CLEANFILES = \
+    @DX_DOCDIR@/@PACKAGE@.tag \
+    -r \
+    $(DX_CLEAN_HTML) \
+    $(DX_CLEAN_CHM) \
+    $(DX_CLEAN_CHI) \
+    $(DX_CLEAN_MAN) \
+    $(DX_CLEAN_RTF) \
+    $(DX_CLEAN_XML) \
+    $(DX_CLEAN_PS) \
+    $(DX_CLEAN_PDF) \
+    $(DX_CLEAN_LATEX)
+
+endif DX_COND_doc