一个线程问题，不知道出啥问题了？

蒋映辉

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ThreadDemo3 {
public static void main(String[] args) {
Resource r=new Resource("鸡腿");
Input in=new Input(r);
Output out=new Output(r);
Thread t1=new Thread(in);
Thread t2=new Thread(in);
Thread t3=new Thread(out);
Thread t4=new Thread(out);
t1.start();
t2.start();
t3.start();
t4.start();

}

}
class Input implements Runnable
{
private Resource r;
Input(Resource r)
{
this.r=r;
}
public void run()
{
while(true)
{
r.set();
}
}
}
class Output implements Runnable
{
private Resource r;
Output(Resource r)
{
this.r=r;
}
public void run()
{
while(true)
{
r.get();
}
}
}
class Resource
{
private String name;
private Lock lock=new ReentrantLock();
private Condition d1=lock.newCondition();
private Condition d2=lock.newCondition();
private boolean flag=false;
public void set()
{
lock.lock();
      try
      {
            while(flag)
            {try{d1.await();}catch(InterruptedException e){}}
            System.out.println(Thread.currentThread().getName()+"商品***"+name);
            flag=false;
            d2.signalAll();

      }finally
      {lock.unlock();}
}
public void get()
{
lock.lock();
   try
            {
            while(!flag)
            {try{d1.await();}catch(InterruptedException e){}}
            System.out.println(Thread.currentThread().getName()+"消费***"+name);
            flag=true;
            d1.signalAll();

            }finally
            {lock.unlock();}
}

public Resource(String name)
{
this.name=name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}

}
运行时只有线程1和2跑起来了，3和4不知道出啥问题了跑不起来，自己看着郁闷的要死

李伟 · 李伟

package cn.itcast.test;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ThreadDemo3 {
      public static void main(String[] args) {
            Resource r=new Resource("鸡腿");
            Input in=new Input(r);
            Output out=new Output(r);
            Thread t1=new Thread(in);
            Thread t2=new Thread(in);
            Thread t3=new Thread(out);
            Thread t4=new Thread(out);
            t1.start();
            t2.start();
            t3.start();
            t4.start();

      }

}
class Input implements Runnable
{
      private Resource r;
      Input(Resource r)
      {
            this.r=r;
      }
      public void run()
      {
            while(true)
            {
               try {
r.set("鸡腿");
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
            }
      }
}
class Output implements Runnable
{
      private Resource r;
      Output(Resource r)
      {
            this.r=r;
      }
      public void run()
      {
            while(true)
            {
                     r.get();
            }
      }
}
class Resource
{
      private String name;
      private int count=1;
      private Lock lock=new ReentrantLock();
      private Condition d1=lock.newCondition();
      private Condition d2=lock.newCondition();
      private boolean flag=false;
      public void set(String name) throws InterruptedException
      {
            lock.lock();
      try
      {
               while(flag)
                    try {
d1.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
               Thread.sleep(1000);
               this.name=name+"-----"+count++;
               System.out.println(Thread.currentThread().getName()+"商品***"+this.name);
               flag=true;//主要是这写反了
               d2.signal();


      }
      finally
      {
           lock.unlock();
      }
      }
      public void get()
      {
            lock.lock();
               try
               {
                        while(!flag)
                        try{d2.await();}catch(InterruptedException e){}

                        System.out.println(Thread.currentThread().getName()+"消费***"+name);
                        flag=false; //主要是这写反了，改过来就好了
                           d1.signal();


               }finally
               {lock.unlock();}
      }

      public Resource(String name)
      {
            this.name=name;
      }
      public String getName() {
            return name;
      }
      public void setName(String name) {
            this.name = name;
      }

}

李伟 · 李伟

public void get()
      {
            lock.lock();
               try
               {
                        while(!flag)
                                 try{d2.await();}catch(InterruptedException e){}//这也反了，改过来就行了
                                 System.out.println(Thread.currentThread().getName()+"消费***"+name);
                                 flag=false; //主要是这写反了，改过来就好了
                                 d1.signal();


               }finally
               {lock.unlock();}
      }

金龙 · 金龙

问题是出在Resource类中，下面是你Resource类的源代码，后面给注释了，正确代码会在下楼贴上

class Resource
{
      private String name;
      private Lock lock=new ReentrantLock();
      private Condition d1=lock.newCondition();
      private Condition d2=lock.newCondition();
      private boolean flag=false;
      public void set()
      {
            lock.lock();
      try
      {
                  while(flag)
                  {try{d1.await();}catch(InterruptedException e){}}
                  System.out.println(Thread.currentThread().getName()+"商品***"+name);
                  flag=false; //首先，你这里标记错了，原本就是false进来的
                  d2.signalAll(); //所以，那里改成true，还有唤醒的这个，改成singnl，不用唤醒全部。

      }finally
      {lock.unlock();}
      }
      public void get()
      {
            lock.lock();
               try
               {
                        while(!flag) //因为你上边的标记改错了，所以这里永远为真
                        {try{d1.await();}catch(InterruptedException e){}}//这里你用的是d1锁，上面唤醒的是d2的哦！所以，永远等待
                        System.out.println(Thread.currentThread().getName()+"消费***"+name);
                        flag=true;//这个标记，从上看，也是反的，应该改为false，消费了没有了就应该是false嘛
                        d1.signalAll();//这里，也不需要唤醒全部的昂。signal就可以了

               }finally
               {lock.unlock();}
      }

      public Resource(String name)
      {
            this.name=name;
      }
      public String getName() {
            return name;
      }
      public void setName(String name) {
            this.name = name;
      }

}

金龙 · 金龙

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ThreadDemo3 {
      public static void main(String[] args) {
            Resource r=new Resource("鸡腿");
            Input in=new Input(r);
            Output out=new Output(r);
            Thread t1=new Thread(in);
            Thread t2=new Thread(in);
            Thread t3=new Thread(out);
            Thread t4=new Thread(out);
            t1.start();
            t2.start();
            t3.start();
            t4.start();

      }

}
class Input implements Runnable
{
      private Resource r;
      Input(Resource r)
      {
            this.r=r;
      }
      public void run()
      {
            while(true)
            {
                     r.set();
            }
      }
}
class Output implements Runnable
{
      private Resource r;
      Output(Resource r)
      {
            this.r=r;
      }
      public void run()
      {
            while(true)
            {
                     r.get();
            }
      }
}
class Resource
{
      private String name;
      private Lock lock=new ReentrantLock();
      private Condition d1=lock.newCondition();
      private Condition d2=lock.newCondition();
      private boolean flag=false;
      public void set()
      {
            lock.lock();
      try
      {
                  while(flag)
                  {try{d1.await();}catch(InterruptedException e){}}
                  System.out.println(Thread.currentThread().getName()+"商品***"+name);
                  flag=true;//这里是改动后的
                  d2.signal();//这里也是改动后的

      }finally
      {lock.unlock();}
      }
      public void get()
      {
            lock.lock();
               try
               {
                        while(!flag)
                        {try{d2.await();}catch(InterruptedException e){}}//这里的d2是改动后的
                        System.out.println(Thread.currentThread().getName()+"消费***"+name);
                        flag=false;//这里也是改动后的
                        d1.signal();//同上

               }finally
               {lock.unlock();}
      }

      public Resource(String name)
      {
            this.name=name;
      }
      public String getName() {
            return name;
      }
      public void setName(String name) {
            this.name = name;
      }

}

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一个线程问题，不知道出啥问题了？

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