Java生产者消费者非法监视器状态异常
我已经使用java线程构建了生产者-消费者。生产者和消费者是指单个LinkedList和对象锁的两个不同类。下面的实现有什么问题Java生产者消费者非法监视器状态异常,java,multithreading,performance,parallel-processing,producer-consumer,Java,Multithreading,Performance,Parallel Processing,Producer Consumer,我已经使用java线程构建了生产者-消费者。生产者和消费者是指单个LinkedList和对象锁的两个不同类。下面的实现有什么问题 Item Produced by Thread-0 Item 1 Item Consumed by Thread-1 Item 1 Exception in thread "Thread-0" Exception in thread "Thread-1" java.lang.IllegalMonitorStateExc
Item Produced by Thread-0 Item 1
Item Consumed by Thread-1 Item 1
Exception in thread "Thread-0" Exception in thread "Thread-1" java.lang.IllegalMonitorStateException
at java.lang.Object.notify(Native Method)
at ProducerConsumer$Producer.produce(ProducerConsumer.java:35)
at ProducerConsumer$Producer.run(ProducerConsumer.java:19)
at java.lang.Thread.run(Thread.java:745)
java.lang.IllegalMonitorStateException
at java.lang.Object.notify(Native Method)
at ProducerConsumer$Consumer.consume(ProducerConsumer.java:63)
at ProducerConsumer$Consumer.run(ProducerConsumer.java:50)
at java.lang.Thread.run(Thread.java:745)
代码实现
import java.util.LinkedList;
public class ProducerConsumer {
LinkedList<Integer> items = new LinkedList<>();
Object lock = new Object();
int capacity = 10;
public static void main(String[] args) {
ProducerConsumer m = new ProducerConsumer();
Thread p = new Thread(m.new Producer());
Thread c = new Thread(m.new Consumer());
p.start();
c.start();
}
class Producer implements Runnable{
@Override
public void run() {
produce();
}
public void produce(){
int value =0;
while(true){
synchronized (lock){
while(items.size() == capacity){
try{
wait();
}catch (InterruptedException e){
e.printStackTrace();
}
}
items.add(++value);
System.out.println("Item Produced by "+Thread.currentThread().getName()+" Item "+value);
notify();
try{
Thread.sleep(1000);
}catch (InterruptedException e){
e.printStackTrace();
}
}
}
}
}
class Consumer implements Runnable{
@Override
public void run() {
consume();
}
public void consume(){
while (true){
synchronized (lock){
while (items.size() == 0){
try{
wait();
}catch (InterruptedException e){
e.printStackTrace();
}
}
System.out.println("Item Consumed by "+Thread.currentThread().getName()+" Item "+items.remove());
notify();
}
}
}
}
}
import java.util.LinkedList;
公共类生产者消费者{
LinkedList items=新建LinkedList();
对象锁=新对象();
国际通行能力=10;
公共静态void main(字符串[]args){
ProducerConsumer m=新的ProducerConsumer();
线程p=新线程(m.newproducer());
线程c=新线程(m.new Consumer());
p、 start();
c、 start();
}
类生成器实现了Runnable{
@凌驾
公开募捐{
产生();
}
公共产品{
int值=0;
while(true){
已同步(锁定){
while(items.size()=容量){
试一试{
等待();
}捕捉(中断异常e){
e、 printStackTrace();
}
}
项目。添加(++值);
System.out.println(“由“+Thread.currentThread().getName()+”Item“+value”生成的项);
通知();
试一试{
睡眠(1000);
}捕捉(中断异常e){
e、 printStackTrace();
}
}
}
}
}
类使用者实现Runnable{
@凌驾
公开募捐{
消费();
}
公共消费(){
while(true){
已同步(锁定){
而(items.size()==0){
试一试{
等待();
}捕捉(中断异常e){
e、 printStackTrace();
}
}
System.out.println(“由”+Thread.currentThread().getName()+“Item”+items.remove()消耗的项”);
通知();
}
}
}
}
}
这是由于调用notify()代码>方法不符合its的要求
唤醒等待此对象监视器的单个线程。
(...)
此方法只能由作为的所有者的线程调用
此对象的监视器。
这同样适用于wait
方法:
此方法只能由作为此对象监视器所有者的线程调用。
TL:DR
您正在错误的锁上调用wait
和notify()
分别将这些调用更改为:
lock.notify()代码>和锁定。等待()代码>
基于提供的代码的运行示例:
import java.util.LinkedList;
public class ProducerConsumer {
final LinkedList<Integer> items = new LinkedList<>();
final Object lock = new Object();
final int capacity = 10;
public static void main(String[] args) {
ProducerConsumer m = new ProducerConsumer();
Thread p = new Thread(m.new Producer());
Thread c = new Thread(m.new Consumer());
p.start();
c.start();
}
class Producer implements Runnable{
@Override
public void run() {
try {
produce();
} catch (InterruptedException e) { /** do something **/ }
}
public void produce() throws InterruptedException {
int value =0;
while(true){
synchronized (lock){
while(items.size() == capacity)
lock.wait();
items.add(++value);
System.out.println("Item Produced by "+Thread.currentThread().getName()+" Item "+value);
lock.notify();
Thread.sleep(1000);
}
}
}
}
class Consumer implements Runnable{
@Override
public void run() {
try {
consume();
} catch (InterruptedException e) { /** do something **/ }
}
public void consume() throws InterruptedException {
while (true){
synchronized (lock){
while (items.size() == 0)
lock.wait();
System.out.println( "Item Consumed by "
+Thread.currentThread().getName()+
" Item "+items.remove());
lock.notify();
}
}
}
}
}
import java.util.LinkedList;
公共类生产者消费者{
最终LinkedList项=新建LinkedList();
最终对象锁=新对象();
最终int容量=10;
公共静态void main(字符串[]args){
ProducerConsumer m=新的ProducerConsumer();
线程p=新线程(m.newproducer());
线程c=新线程(m.new Consumer());
p、 start();
c、 start();
}
类生成器实现了Runnable{
@凌驾
公开募捐{
试一试{
产生();
}catch(InterruptedException e){/**做点什么**/}
}
public void product()引发InterruptedException{
int值=0;
while(true){
已同步(锁定){
while(items.size()=容量)
lock.wait();
项目。添加(++值);
System.out.println(“由“+Thread.currentThread().getName()+”Item“+value”生成的项);
lock.notify();
睡眠(1000);
}
}
}
}
类使用者实现Runnable{
@凌驾
公开募捐{
试一试{
消费();
}catch(InterruptedException e){/**做点什么**/}
}
public void consume()引发InterruptedException{
while(true){
已同步(锁定){
而(items.size()==0)
lock.wait();
System.out.println(“消耗的项目”
+Thread.currentThread().getName()+
“Item”+items.remove());
lock.notify();
}
}
}
}
}
import java.util.LinkedList;
public class ProducerConsumer {
final LinkedList<Integer> items = new LinkedList<>();
final Object lock = new Object();
final int capacity = 10;
public static void main(String[] args) {
ProducerConsumer m = new ProducerConsumer();
Thread p = new Thread(m.new Producer());
Thread c = new Thread(m.new Consumer());
p.start();
c.start();
}
class Producer implements Runnable{
@Override
public void run() {
try {
produce();
} catch (InterruptedException e) { /** do something **/ }
}
public void produce() throws InterruptedException {
int value =0;
while(true){
synchronized (lock){
while(items.size() == capacity)
lock.wait();
items.add(++value);
System.out.println("Item Produced by "+Thread.currentThread().getName()+" Item "+value);
lock.notify();
Thread.sleep(1000);
}
}
}
}
class Consumer implements Runnable{
@Override
public void run() {
try {
consume();
} catch (InterruptedException e) { /** do something **/ }
}
public void consume() throws InterruptedException {
while (true){
synchronized (lock){
while (items.size() == 0)
lock.wait();
System.out.println( "Item Consumed by "
+Thread.currentThread().getName()+
" Item "+items.remove());
lock.notify();
}
}
}
}
}