zookeeper curator 可重入与不可重入分布式锁
转载自https://www.cnblogs.com/zhangjunqing/p/7823626.html基础知识:http://www.cnblogs.com/LiZhiW/p/4931577.html项目路径:https://gitee.com/zhangjunqing/spring-boot1 可重入读写锁示例代码如下(lock.acquire加几个,就必须使用几个lo
·
转载自https://www.cnblogs.com/zhangjunqing/p/7823626.html
基础知识:http://www.cnblogs.com/LiZhiW/p/4931577.html
项目路径:https://gitee.com/zhangjunqing/spring-boot
1 可重入读写锁示例代码如下(lock.acquire加几个,就必须使用几个lock.release()释放):
package com.topsec.lock;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.curator.retry.ExponentialBackoffRetry;
/**
* 测试可重入锁(可以多次获得锁不会被阻塞,释放时也需释放多把锁)
* @author 76524
*
*/
public class SharedReentrantLock1 implements Runnable{
private InterProcessMutex lock;//可重入锁实现类
private String lockPAth = "/lock/shareLock";
private int i;
private String clientName;
//zookeeper集群地址
public static final String ZOOKEEPERSTRING = "192.168.99.129:2181,192.168.99.153:2181,192.168.99.171:2181";
public SharedReentrantLock1(CuratorFramework client,String clientName) {
lock = new InterProcessMutex(client, lockPAth);
this.clientName = clientName;
}
public void run() {
try {
Thread.sleep((new java.util.Random().nextInt(2000)));
lock.acquire(); //增加第一把锁
if(lock.isAcquiredInThisProcess()) {
System.out.println(clientName + " 获得锁");
i++;
}
lock.acquire(); //增加第二把锁
} catch (Exception e) {
e.printStackTrace();
}finally {
try {
System.out.println(clientName+"释放第一把锁");
lock.release();
System.out.println(clientName+"释放第二把锁");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void main(String[] args) {
CuratorFramework client = CuratorFrameworkFactory.newClient(ZOOKEEPERSTRING, new ExponentialBackoffRetry(1000, 3));
client.start();
//启动100个线程进行测试
for(int i = 0;i<100;i++) {
SharedReentrantLock1 sharedReentrantLock = new SharedReentrantLock1(client, "第"+i+"个客户端:");
Thread thread = new Thread(sharedReentrantLock);
thread.start();
}
}
}
2:不可重入锁示例代码如下(lock.acquire加几个都只相当于加一个):
package com.topsec.lock;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.locks.InterProcessSemaphoreMutex;
import org.apache.curator.retry.ExponentialBackoffRetry;
/**
* 测试不可重入锁(只能获得一次锁,使用完后释放)
* @author 76524
*
*/
public class SharedNOReentrantLock implements Runnable{
private InterProcessSemaphoreMutex lock;//不可重入锁
private String lockPAth = "/lock/shareLock";
private int i;
private String clientName;
//zookeeper集群地址
public static final String ZOOKEEPERSTRING = "192.168.99.129:2181,192.168.99.153:2181,192.168.99.171:2181";
public SharedNOReentrantLock(CuratorFramework client,String clientName) {
lock = new InterProcessSemaphoreMutex(client, lockPAth);
this.clientName = clientName;
}
public void run() {
try {
Thread.sleep((new java.util.Random().nextInt(2000)));
lock.acquire(); //增加第一把锁
if(lock.isAcquiredInThisProcess()) {
System.out.println(clientName + " 获得锁");
i++;
}
lock.acquire(); //增加第二把锁这个锁相当于不起作用
} catch (Exception e) {
e.printStackTrace();
}finally {
try {
// lock.release();
System.out.println(clientName+"释放第一把锁");
lock.release();
System.out.println(clientName+"释放第二把锁");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void main(String[] args) {
CuratorFramework client = CuratorFrameworkFactory.newClient(ZOOKEEPERSTRING, new ExponentialBackoffRetry(1000, 3));
client.start();
for(int i = 0;i<100;i++) {
SharedReentrantLock2 sharedReentrantLock = new SharedReentrantLock2(client, "第"+i+"个客户端:");
Thread thread = new Thread(sharedReentrantLock);
thread.start();
}
}
}
ps:最后的基于信号量的不可重入锁,看其构造方法其实maxLeases的值设置为1,这样每次只能有一个获取到锁,其他等待其释放lease后才能获取到锁。
更多推荐
已为社区贡献2条内容
所有评论(0)