实现方案
方案一：使用LockSupport
package com.jesse.review.test4;
import java.util.concurrent.locks.LockSupport;
/**
* Created by Kong on 2021/1/13.
*/
public class Test41 {
static Thread threadA, threadB, threadC;
public static void main(String[] args) {
threadA = new Thread(() -> {
for (int i = 0; i < 10; i++) {
System.out.print(Thread.currentThread().getName());
LockSupport.unpark(threadB);
LockSupport.park();
}
}, "A");
threadB = new Thread(() -> {
for (int i = 0; i < 10; i++) {
LockSupport.park();
System.out.print(Thread.currentThread().getName());
LockSupport.unpark(threadC);
}
}, "B");
threadC = new Thread(() -> {
for (int i = 0; i < 10; i++) {
LockSupport.park();
System.out.print(Thread.currentThread().getName());
LockSupport.unpark(threadA);
}
}, "C");
threadA.start();
threadB.start();
threadC.start();
}
}
方案二：使用synchronized
package com.jesse.review.test4;
/**
* Created by Kong on 2021/1/13.
*/
public class Test42 {
private static boolean startA = true;
private static boolean startB = false;
private static boolean startC = false;
public static void main(String[] args) {
final Object o = new Object();
new Thread(() -> {
synchronized (o){
for(int i = 0; i < 10;){
if(startA){
System.out.print(Thread.currentThread().getName());
startA = false;
startB = true;
startC = false;
o.notifyAll();
i++;
}else {
try {
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}, "A").start();
new Thread(() -> {
synchronized (o){
for(int i = 0; i < 10;){
if(startB){
System.out.print(Thread.currentThread().getName());
startA = false;
startB = false;
startC = true;
o.notifyAll();
i++;
}else {
try {
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}, "B").start();
new Thread(() -> {
synchronized (o){
for(int i = 0; i < 10;){
if(startC){
System.out.print(Thread.currentThread().getName());
startA = true;
startB = false;
startC = false;
o.notifyAll();
i++;
}else {
try {
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}, "C").start();
}
}
方案三：使用Lock搭配Condition实现
package com.jesse.review.test4;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
/**
* Created by Kong on 2021/1/13.
*/
public class Test43 {
public static void main(String[] args) {
ReentrantLock lock = new ReentrantLock();
Condition conditionA = lock.newCondition();
Condition conditionB = lock.newCondition();
Condition conditionC = lock.newCondition();
new Thread(() -> {
try{
lock.lock();
for (int i = 0; i < 10; i++) {
System.out.print(Thread.currentThread().getName());
conditionB.signal();
conditionA.await();
}
conditionB.signal();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
},"A").start();
new Thread(() -> {
try{
lock.lock();
for (int i = 0; i < 10; i++) {
System.out.print(Thread.currentThread().getName());
conditionC.signal();
conditionB.await();
}
conditionC.signal();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
},"B").start();
new Thread(() -> {
try{
lock.lock();
for (int i = 0; i < 10; i++) {
System.out.print(Thread.currentThread().getName());
conditionA.signal();
conditionC.await();
}
conditionA.signal();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
},"C").start();
}
}
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