1. 程式人生 > >JAVA多執行緒使用JDK1.5提供的Lock,Condition手寫阻塞佇列

JAVA多執行緒使用JDK1.5提供的Lock,Condition手寫阻塞佇列

package com.study;

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

public class BlockingQueueDemo {
  public static void main(String[] args) {
    BlockingQueueDemo blockingQueueDemo = new BlockingQueueDemo();
    final BlockingQueueClass blockingQueueClass = blockingQueueDemo.new BlockingQueueClass();
    Thread thread = new Thread(new Runnable() {
      @Override
      public void run() {
        while(true){
          int value = new Random().nextInt();
          System.out.println("準備存資料了");
          blockingQueueClass.put(value);
          System.out.println("已經存好資料了");
        }
      }
    });
    thread.start();
    
    Thread thread2 = new Thread(new Runnable() {
      @Override
      public void run() {
        while(true){
          System.out.println("準備取資料了");
          Object value = blockingQueueClass.take();
          System.out.println("取到的資料為:" + value);
        }
      }
    });
    thread2.start();
  }
  class BlockingQueueClass{
    Lock lock = new ReentrantLock();
    Condition notFullCondition = lock.newCondition();
    Condition notEmptyCondition = lock.newCondition();
    Object[] items = new Object[100];
    private int putLength,takeLength,count;
    
    public void put(Object object){
      lock.lock();
      try {
        while(count == items.length){
          try {
            notFullCondition.await();
          } catch (InterruptedException error) {
            error.printStackTrace();
          }
        }
        items[putLength] = object;
        if(++putLength == items.length){
          putLength = 0;
        }
        ++count;
        notEmptyCondition.signal();
      } catch (Exception e) {
        e.printStackTrace();
      } finally{
        lock.unlock();
      }
      
    }
    
    public Object take(){
      Object object = new Object();
      lock.lock();
      try {
        while(count == 0){
          try {
            notEmptyCondition.await();
          } catch (InterruptedException e) {
            e.printStackTrace();
          }
        }
        object = items[takeLength];
        if(++takeLength == items.length){
          takeLength = 0;
        }
        --count;
        notFullCondition.signal();
      } catch (Exception e) {
        e.printStackTrace();
        lock.unlock();
      }
      return object;
    }
  }
}