[211125] 교육 25일차

스레드

wait(), notify()

class ShampooAI extends Thread {
	private Table tbl = null;
	public ShampooAI( Table t ) {
		this.tbl = t;
	}
	public void run() {
		for( int i = 0 ; i < 300 ; i++ ) {
			String d = "dish " + i;
			tbl.on( d );
		}
	}
}
//
class WashAI extends Thread {
	private Table tbl = null;
	public WashAI( Table t ) {
		this.tbl = t;
	}
	public void run() {
		for( int i = 0 ; i < 300 ; i++ ) {
			String d = tbl.off();
		}
	}
}
//
class Table {
	private List<String> dishes = null;
	public Table() {
		dishes = new LinkedList<String>();
	}
    //
	public synchronized void on( String dish ) {  
		while( dishes.size() == 5 ) {
			try {
				wait();	//	이 함수 호출하는 쓰레드야 너 멈춰
			}
			catch( InterruptedException e ){}
		}
		System.out.println( dish + " : on the table" );
		dishes.add( dish ); 
		notify();
    //
	public synchronized String off() {
		while( dishes.size() == 0 ) {
			try {
				wait();	//	이 함수 호출하는 쓰레드야 너 멈춰 ( 여기서는 워시가 된다 )
			}
			catch( InterruptedException e ){}
		}
		String d = dishes.remove( dishes.size() - 1 );
		System.out.println( d + " : off the table" );
		notify();	//	자신이 멈춘 쓰레드를 다시 일하도록 한다.
		return d;
	}
}
//
public class Test219 {
	public static void main( String[] args ) {
		Table table = new Table();
		Thread s = new ShampooAI( table );
		Thread w = new WashAI( table );
		s.start();
		w.start();
	}
}

실행결과>>
dish 0 : on the table
dish 0 : off the table
dish 1 : on the table
dish 1 : off the table
dish 2 : on the table
dish 2 : off the table
dish 3 : on the table
dish 3 : off the table
dish 4 : on the table
dish 4 : off the table
dish 5 : on the table
dish 5 : off the table