目录
监测Lock(ReentrantLock)
一、主程序
二、拓展ReentrantLock
三、使用锁的任务
四、执行结果
监测Lock(ReentrantLock)
getOwner()：持锁线程。getQueuedThreads()：等待锁的线程列表。hasQueuedThreads(): 是否有等待锁的线程。getQueueLength(): 等待锁的线程数量。isLocked(): 是否有线程持有锁。isFair(): 是否公平锁
一、主程序
package xyz.jangle.thread.test.n9_2.testlock;
import java.util.concurrent.TimeUnit;
/**
* 9.2、监测Lock接口
*
* @author jangle
* @email jangle@jangle.xyz
* @time 2020年10月21日 下午9:20:12
*
*/
public class M {
public static void main(String[] args) throws Exception {
var lock = new MyLock();
Thread threads[] = new Thread[5];
for (int i = 0; i < 5; i++) {
var task = new Task(lock);
threads[i] = new Thread(task);
threads[i].start();
}
for (int i = 0; i < 15; i++) {
System.out.println("M:Log :**********");
System.out.println("Lock:Owner:"+lock.getOwnerName());
if(lock.hasQueuedThreads()) {
System.out.print("Lock:排队中的线程："+lock.getQueueLength()+"个 :");
var lockedThreads = lock.getThreads();
for (Thread thread : lockedThreads) {
System.out.print(thread.getName()+" | ");
}
}
System.out.println("\n Lock:fairness(是否公平锁):"+lock.isFair()+"、Locked(锁状态):"+lock.isLocked());
TimeUnit.SECONDS.sleep(1);
}
}
}
二、拓展ReentrantLock
package xyz.jangle.thread.test.n9_2.testlock;
import java.util.Collection;
import java.util.concurrent.locks.ReentrantLock;
/**
* @author jangle
* @email jangle@jangle.xyz
* @time 2020年10月21日 下午9:22:34
*
*/
@SuppressWarnings("serial")
public class MyLock extends ReentrantLock {
/**
*
* 获取当前持锁线程名称
* @return
*/
public String getOwnerName() {
if(this.getOwner() == null) {
return "None";
}
return this.getOwner().getName();
}
/**
*
* 获取当前线程队列
* @return
*/
public Collection<Thread> getThreads() {
return this.getQueuedThreads();
}
}
三、使用锁的任务
package xyz.jangle.thread.test.n9_2.testlock;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
/**
* @author jangle
* @email jangle@jangle.xyz
* @time 2020年10月21日 下午9:29:11
*
*/
public class Task implements Runnable {
private final Lock lock;
public Task(Lock lock) {
super();
this.lock = lock;
}
@Override
public void run() {
for (int i = 0; i < 5; i++) {
lock.lock();
System.out.println(Thread.currentThread().getName() + ":获取了当前锁");
try {
TimeUnit.MILLISECONDS.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}
}
四、执行结果
M:Log :**********
Lock:Owner:None
Thread-2:获取了当前锁
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-2:获取了当前锁
M:Log :**********
Thread-2:获取了当前锁
Lock:Owner:Thread-2
Lock:排队中的线程：4个 :Thread-1 | Thread-3 | Thread-0 | Thread-4 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-2:获取了当前锁
Thread-2:获取了当前锁
M:Log :**********
Lock:Owner:Thread-2
Lock:排队中的线程：4个 :Thread-1 | Thread-3 | Thread-0 | Thread-4 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-4:获取了当前锁
M:Log :**********
Lock:Owner:Thread-4
Lock:排队中的线程：3个 :Thread-4:获取了当前锁
Thread-1 | Thread-3 | Thread-0 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-4:获取了当前锁
M:Log :**********
Thread-4:获取了当前锁
Lock:Owner:Thread-4
Lock:排队中的线程：3个 :Thread-1 | Thread-3 | Thread-0 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-4:获取了当前锁
M:Log :**********
Lock:Owner:Thread-0
Lock:排队中的线程：2个 :Thread-0:获取了当前锁
Thread-1 | Thread-3 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-0:获取了当前锁
M:Log :**********
Thread-0:获取了当前锁
Lock:Owner:Thread-0
Lock:排队中的线程：2个 :Thread-1 | Thread-3 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-0:获取了当前锁
M:Log :**********
Lock:Owner:Thread-0
Lock:排队中的线程：2个 :Thread-0:获取了当前锁
Thread-1 | Thread-3 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-3:获取了当前锁
M:Log :**********
Lock:Owner:Thread-3
Lock:排队中的线程：1个 :Thread-1 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-3:获取了当前锁
Thread-3:获取了当前锁
M:Log :**********
Lock:Owner:Thread-3
Lock:排队中的线程：1个 :Thread-1 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-3:获取了当前锁
Thread-3:获取了当前锁
M:Log :**********
Lock:Owner:Thread-3
Lock:排队中的线程：1个 :Thread-1 |
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-1:获取了当前锁
Thread-1:获取了当前锁
M:Log :**********
Lock:Owner:Thread-1
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-1:获取了当前锁
Thread-1:获取了当前锁
M:Log :**********
Lock:Owner:Thread-1
Lock:fairness(是否公平锁):false、Locked(锁状态):true
Thread-1:获取了当前锁
M:Log :**********
Lock:Owner:None
Lock:fairness(是否公平锁):false、Locked(锁状态):false
M:Log :**********
Lock:Owner:None
Lock:fairness(是否公平锁):false、Locked(锁状态):false
