package com.git.zookeeper.passwordmanager.lock;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

import org.apache.commons.lang.math.RandomUtils;
import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.ACLProvider;
import org.apache.curator.framework.recipes.locks.InterProcessLock;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.curator.framework.recipes.locks.InterProcessReadWriteLock;
import org.apache.curator.framework.recipes.locks.InterProcessSemaphoreV2;
import org.apache.curator.framework.recipes.locks.Lease;
import org.apache.curator.framework.recipes.shared.SharedCount;
import org.apache.curator.retry.RetryNTimes;
import org.apache.zookeeper.ZooDefs.Perms;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Id;

/**
 * zookeeper 锁功能的演示 基于curator
 * 
 * @author songqinghu
 *
 *共享锁: 全局同步分布式锁, 同一时间两台机器只有一台能获得同一把锁. 
 *共享读写锁: 用于分布式的读写互斥处理, 同时生成两个锁:一个读锁, 一个写锁,
 *        读锁能被多个应用持有, 而写锁只能一个独占, 当写锁未被持有时, 多个读锁持有者可以同时进行读操作 
 *共享信号量: 在分布式系统中的各个JVM使用同一个zk lock path,
 *      该path将跟一个给定数量的租约(lease)相关联, 然后各个应用根据请求顺序获得对应的lease, 
 *      相对来说, 这是最公平的锁服务使用方式. 
 *多共享锁:内部构件多个共享锁(会跟一个znode path关联), 在acquire()过程中,
 *     执行所有共享锁的acquire()方法, 如果中间出现一个失败, 则将释放所有已require的共享锁; 
 *      执行release()方法时, 则执行内部多个共享锁的release方法(如果出现失败将忽略) 
 */
public class ZookeeperLockDemo {

    private static CuratorFramework client ;
    
    public static void main(String[] args) {
        
        //testSharedLock();
       // testReadWriterLock();
        for (int i = 0; i < 4; i++) {
            testSharedSemaphore(i);
        }
    }
    
    /*
     * 共享锁测试
     */
    private static void testSharedLock(){
        Thread t1 = new Thread("t1"){
            public void run(){
                sharedLock();
            }
        };
        Thread t2 = new Thread("t2"){
            public void run(){
                sharedLock();
            }
        };
        t1.start();
        t2.start();
    }
    
    /**
     * 
     * @描述：第一种锁: 共享锁
     * @return void
     * @exception
     * @createTime：2016年5月19日
     * @author: songqinghu
     * @throws Exception 
     */
    private static void sharedLock(){
        CuratorFramework client = getClient();
        //这两个都是共享锁
       // new InterProcessMutex(client, path)
       // new InterProcessSemaphoreMutex(client, path)
        
        InterProcessMutex sharedLock = new InterProcessMutex(client, "/sharedlock");
        try {
            //锁是否被获取到
            //超时 不在进行操作
              if(sharedLock.acquire(50, TimeUnit.MILLISECONDS)){
                //sharedLock.acquire();
                System.out.println(Thread.currentThread().getName() + "  is  get the shared lock");
                Thread.sleep(100000);
                System.out.println(Thread.currentThread().getName() + "  is  release the shared lock");
            }
            
        } catch (Exception e) {
            //日志记录一下 超时说明 有锁 可以不在操作
            
        }finally {
            try {
                System.out.println(Thread.currentThread().getName() + "  the flag is " + sharedLock.isAcquiredInThisProcess());
                if(sharedLock.isAcquiredInThisProcess())//判断是否持有锁 进而进行锁是否释放的操作
                sharedLock.release();
            } catch (Exception e) {
                e.printStackTrace();
            }
            
        }
    }
    /**
     * 
     * @描述：测试读写锁
     * @return void
     * @exception
     * @createTime：2016年5月19日
     * @author: songqinghu
     */
    private static void testReadWriterLock(){
        //创建多线程 循环进行锁的操作
        CuratorFramework client = getClient();
        
        InterProcessReadWriteLock readWriteLock = new InterProcessReadWriteLock(client, "/readwriter");
       final  InterProcessMutex readLock = readWriteLock.readLock();
       final  InterProcessMutex writeLock = readWriteLock.writeLock();
        
        List<Thread> jobs = new ArrayList<Thread>();
        
        for (int i = 0; i < 20; i++) {
            Thread t = new Thread("写锁  " + i){
                
                public void run(){
                    readWriterLock(writeLock);
                }
            };
            jobs.add(t);
        }
        
        for (int i = 0; i < 1; i++) {
            Thread t = new Thread("读锁  " + i){
                
                public void run(){
                    readWriterLock(readLock);
                }
            };
            jobs.add(t);
        }
        
        for (Thread thread : jobs) {
            thread.start();
        }
        
    }
    
    /**
     * 
     * @描述：读写锁演示
     * @return void
     * @exception
     * @createTime：2016年5月19日
     * @author: songqinghu
     */
    private static void readWriterLock(InterProcessLock lock){
        System.out.println(Thread.currentThread().getName()+"   进入任务 " + System.currentTimeMillis());
        try {
            if(lock.acquire(20, TimeUnit.MILLISECONDS)){
                //System.err.println(Thread.currentThread().getName() + " 等待超时  无法获取到锁");
            //执行任务 --读取 或者写入
               int time = RandomUtils.nextInt(150);
               
               System.out.println(Thread.currentThread().getName()+"   执行任务开始");
               Thread.sleep(time);
              System.out.println(Thread.currentThread().getName()+"   执行任务完毕");
            }else{
              System.err.println(Thread.currentThread().getName() + " 等待超时  无法获取到锁"); 
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                if(lock.isAcquiredInThisProcess())
                    lock.release();
            } catch (Exception e2) {
            
            }
        }
        
    }
    
    
    private static void testSharedSemaphore(final int x){
        CuratorFramework client = getClient();
        final InterProcessSemaphoreV2 semaphoreV2 = 
               /// new InterProcessSemaphoreV2(client, "/sharedsemaphore", 50);
                new InterProcessSemaphoreV2(client, "/sharedsemaphore",
                        new SharedCount(client, "/semaphore", 2));
        List<Thread> jobs  = new ArrayList<Thread>();
        for (int i = 0; i < 2; i++) {
            Thread thread = new Thread(x +"　　共享信息锁 " + i){
                public void run(){
                    sharedSemaphore(semaphoreV2);
                }
            };
            jobs.add(thread);
        }
        for (Thread thread : jobs) {
            thread.start();
        }
    }
    
    
    /**
     * 共享信号量
     * 设置总的数量 -->分布式情况下的最大并行数量
     * 按照请求顺序进行 执行权的分配
     * 可以设置超时 不执行 也可以设置 直到获取执行权 执行
     */
    private static void sharedSemaphore(InterProcessSemaphoreV2 semaphoreV2){
        //CuratorFramework client = getClient();
       // new InterProcessSemaphoreV2(client, path, maxLeases)
       // new InterProcessSemaphoreV2(client, path, count)
        
        Lease lease = null;
        try {
           // lease = semaphoreV2.acquire(10, TimeUnit.MILLISECONDS);
            lease = semaphoreV2.acquire();
            if(lease != null){
                System.out.println(Thread.currentThread().getName()+"   执行任务开始" + System.currentTimeMillis());
                //Thread.sleep(RandomUtils.nextInt(4000));
                Thread.sleep(1000);
                System.out.println(Thread.currentThread().getName()+"   执行任务完毕" + System.currentTimeMillis());
            }
            
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try {
                if(lease !=null)
                    semaphoreV2.returnLease(lease);
            } catch (Exception e2) {
                e2.printStackTrace();
            }
            
            
        }
        
        
        
        
    }
    
    
    
    /**
     * 
     * @描述：获取连接
     * @return void
     * @exception
     * @createTime：2016年5月19日
     * @author: songqinghu
     */
    private static CuratorFramework getClient(){
        if(client ==null){
            
            ACLProvider aclProvider = new ACLProvider() {
                private List<ACL> acl;
                //初始化操作
                private synchronized void init(){
                    if(acl ==null){
                        acl = new ArrayList<ACL>();
                        acl.add(new ACL(Perms.ALL, new Id("auth","admin:admin")));
                    }
                }
                @Override
                public List<ACL> getDefaultAcl() {
                    if(acl ==null){
                        init();
                    }
                    return this.acl;
                }
                @Override
                public List<ACL> getAclForPath(String path) {
                    if(acl ==null){
                        init();
                    }
                    return this.acl;
                }
            };
            String scheme = "digest";
            byte[] auth = "admin:admin".getBytes();
            int connectionTimeoutMs =5000;
            String connectString = "10.125.2.44:2181";
            byte[] defaultData ="默认数据".getBytes();
            int maxCloseWaitMs = 5000;
            String namespace = "testlock";
            RetryPolicy retryPolicy = new RetryNTimes(Integer.MAX_VALUE, 5000);
            CuratorFramework clientinit = CuratorFrameworkFactory.builder().aclProvider(aclProvider).authorization(scheme, auth)
                    .connectionTimeoutMs(connectionTimeoutMs).connectString(connectString).
                    defaultData(defaultData).maxCloseWaitMs(maxCloseWaitMs).namespace(namespace)
                    .retryPolicy(retryPolicy).build();
            
            clientinit.start(); 
            client = clientinit;
        }
        return client;
    }
    
    
    
    
    
    
}