题目:多线程之间按顺序调用,实现A->B->C三个线程启动,要求如下:
- AA打印5次,BB打印10次,CC打印15次
- …来十轮
思路:使用Lock锁的多个Condition实现精准唤醒。
package com.bestqiang.thread.Queue;
/** * @author BestQiang */
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/** * 题目:多线程之间按顺序调用,实现A->B->C三个线程启动,要求如下: * AA打印5次,BB打印10次,CC打印15次 * 然后 * AA打印5次,BB打印10次,CC打印15次 * ...来十轮 */
public class SyncAndReentrantLockDemo {
public static void main(String[] args) {
ShareResource shareResource = new ShareResource();
new Thread(() -> {
for (int i = 0; i < 10; i++) {
shareResource.print5();
}
}, "线程1:").start();
new Thread(() -> {
for (int i = 0; i < 10; i++) {
shareResource.print10();
}
}, "线程2:").start();
new Thread(() -> {
for (int i = 0; i < 10; i++) {
shareResource.print15();
}
}, "线程3:").start();
}
}
class ShareResource {
private int number = 1; // A:1 B:2 C:3
private Lock lock = new ReentrantLock();
Condition c1 = lock.newCondition();
Condition c2 = lock.newCondition();
Condition c3 = lock.newCondition();
public void print5() {
try {
lock.lock();
while (number != 1) {
c1.await();
}
for (int i = 0; i < 5; i++) {
System.out.println("AA");
}
number = 2;
c2.signal();
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
public void print10() {
try {
lock.lock();
while (number != 2) {
c2.await();
}
for (int i = 0; i < 10; i++) {
System.out.println("BB");
}
number = 3;
c3.signal();
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
public void print15() {
try {
lock.lock();
while (number != 3) {
c3.await();
}
for (int i = 0; i < 15; i++) {
System.out.println("CC");
}
number = 1;
c1.signal();
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}