import java.util.concurrent.locks.*;
class Resource // 封装水果资源，提供放水果和吃水果方法。
{
private String name;
private static int ap = 0; // 苹果信号，0表示无，1表示有
private static int or = 0; // 橘子信号，0表示无，1表示有
private static int pz = 0; // 盘子有无水果信号，0表示无，1表示有
Lock lock = new ReentrantLock(); // 锁对象
Condition fmther_lock = lock.newCondition();// 爸妈共用监视器，可以唤醒爸妈其中一个放水果
Condition son_lock = lock.newCondition(); // 儿子监视器
Condition daughter_lock = lock.newCondition(); // 女儿监视器
// 放水果,i=1表示是爸爸，i=2表示是妈妈
void put(String name, int i) {
lock.lock();
try {
Thread.sleep(500);
} catch (Exception e) {
e.printStackTrace();
}
try {
while (pz == 1) // 盘子有水果
{
try {
fmther_lock.await();
} catch (Exception e) {
e.printStackTrace();
}
}
if (i == 1) // 爸爸
{
ap = 1;
pz = 1;
this.name = name; // 此处赋值防止线程中断名字不符（错乱）
System.out.println(this.name + "放苹果");
son_lock.signal();
} else if (i == 2) // 妈妈
{
or = 1;
pz = 1;
this.name = name; // 此处赋值防止线程中断名字不符（错乱）
System.out.println(this.name + "放橘子");
daughter_lock.signal();
}
} finally {
lock.unlock();
}
}
// 吃水果,i=1表示是儿子，i=2表示是女儿
void eat(String name, int i) {
lock.lock();
try {
Thread.sleep(500);
} catch (Exception e) {
e.printStackTrace();
}
try {
while (i == 1) // 儿子
{
while (ap == 0) {
try {
son_lock.await();
} catch (Exception e) {
e.printStackTrace();
}
}
ap = 0;
pz = 0;
this.name = name; // 此处赋值防止线程中断名字不符（错乱）
System.out.println(this.name + "吃苹果");
fmther_lock.signal();
}
while (i == 2) // 女儿
{
while (or == 0) {
try {
daughter_lock.await();
} catch (Exception e) {
e.printStackTrace();
}
}
or = 0;
pz = 0;
this.name = name; // 此处赋值防止线程中断名字不符（错乱）
System.out.println(this.name + "吃橘子");
fmther_lock.signal();
}
} finally {
lock.unlock();
}
}
}
class FatherPut implements Runnable {
private Resource r;
FatherPut(Resource r) {
this.r = r;
}
public void run() {
while (true) {
r.put("爸爸", 1);
}
}
}
class MotherPut implements Runnable {
private Resource r;
MotherPut(Resource r) {
this.r = r;
}
public void run() {
while (true) {
r.put("妈妈", 2);
}
}
}
class SonEat implements Runnable {
private Resource r;
SonEat(Resource r) {
this.r = r;
}
public void run() {
while (true) {
r.eat("儿子", 1);
}
}
}
class DaughterEat implements Runnable {
private Resource r;
DaughterEat(Resource r) {
this.r = r;
}
public void run() {
while (true) {
r.eat("女儿", 2);
}
}
}
public class EatFruit {
public static void main(String[] args) {
Resource r = new Resource();
FatherPut fa = new FatherPut(r);
MotherPut mo = new MotherPut(r);
SonEat son = new SonEat(r);
DaughterEat dau = new DaughterEat(r);
Thread t0 = new Thread(fa);
Thread t1 = new Thread(mo);
Thread t2 = new Thread(son);
Thread t3 = new Thread(dau);
t0.start();
t1.start();
t2.start();
t3.start();
}
}
