20171227.初めてのマルチスレッド@jjugナイトセミナー プレゼン用ソースコード

IOByExec.java

import java.io.*;
import java.util.*;
import java.util.concurrent.*;

public class IOByExec implements Runnable{

    private ExecutorService exec = Executors.newCachedThreadPool();
    private String name;
    private int count;
    
    public IOByExec(String name, int count){
        this.name = name;
        this.count = count;
    }
    
    @Override
    public void run(){
        try{
            File f = new File(name);
            PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(f)));
            for (int i=1; i<=count; i++){
                pw.print(emojis.get((int)(Math.random()*189)));
                if(i%100==0){pw.println();}
            }
            pw.close();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    
    public void doExecute(){
        for (String name: Arrays.asList("temp1","temp2","temp3","temp4","temp5")){
            exec.submit(new IOByExec(name, count));
        };
        exec.shutdown();
        while(!exec.isShutdown()){}
        return;
    }
    
    private List<String> emojis = Arrays.asList(
		"😄","😃","😀","😊","☺","😉","😍","😘","😚","😗","😙",
		"😜","😝","😛","😳","😁","😔","😌","😒","😞","😣","😢",
		"😂","😭","😪","😥","😰","😅","😓","😩","😫","😨","😱",
		"😠","😡","😤","😖","😆","😋","😷","😎","😴","😵","😲",
		"😟","😦","😧","😈","👿","😮","😬","😐","😕","😯","😶",
		"😇","😏","😑","👲","👳","👮","👷","💂","👶","👦","👧",
		"👨","👩","👴","👵","👱","👼","👸","😺","😸","😻","😽",
		"😼","🙀","😿","😹","😾","👹","👺","🙈","🙉","🙊","💀",
		"👽","💩","🔥","✨","🌟","💫","💥","💢","💦","💧","💤",
		"💨","👂","👀","👃","👅","👄","👍","👎","👌","👊","✊",
		"✌","👋","✋","👐","👆","👇","👉","👈","🙌","🙏","☝",
		"👏","💪","🚶","🏃","💃","👫","👪","👬","👭","💏","💑",
		"👯","🙆","🙅","💁","🙋","💆","💇","💅","👰","🙎","🙍",
		"🙇","🎩","👑","👒","👟","👞","👡","👠","👢","👕","👔",
		"👚","👗","🎽","👖","👘","👙","💼","👜","👝","👛","👓",
		"🎀","🌂","💄","💛","💙","💜","💚","❤","💔","💗","💓",
		"💕","💖","💞","💘","💌","💋","💍","💎","👤","👥","💬",
		"👣","💭"
	);
    
    public static void main(String[] args){
        long start = System.nanoTime();
        IOByExec io = new IOByExec("", Integer.valueOf(args[0]));
        io.doExecute();
        
      
        long end = System.nanoTime();
        System.out.println(end - start);
    }

}

IOByFJ.java

import java.io.*;
import java.util.*;
import java.util.concurrent.*;

public class IOByFJ extends RecursiveAction{
    
    private final String name;
    private int count;
    
    public IOByFJ(String name, int count){
        this.name = name;
        this.count = count;
    }
    
    @Override
    public void compute(){
        try{
            File f = new File(name);
            PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(f)));
            for (int i=1; i<=count; i++){
                pw.print(emojis.get((int)(Math.random()*189)));
                if(i%100==0){pw.println();}
            }
            pw.close();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    
    private List<String> emojis = Arrays.asList(
		"😄","😃","😀","😊","☺","😉","😍","😘","😚","😗","😙",
		"😜","😝","😛","😳","😁","😔","😌","😒","😞","😣","😢",
		"😂","😭","😪","😥","😰","😅","😓","😩","😫","😨","😱",
		"😠","😡","😤","😖","😆","😋","😷","😎","😴","😵","😲",
		"😟","😦","😧","😈","👿","😮","😬","😐","😕","😯","😶",
		"😇","😏","😑","👲","👳","👮","👷","💂","👶","👦","👧",
		"👨","👩","👴","👵","👱","👼","👸","😺","😸","😻","😽",
		"😼","🙀","😿","😹","😾","👹","👺","🙈","🙉","🙊","💀",
		"👽","💩","🔥","✨","🌟","💫","💥","💢","💦","💧","💤",
		"💨","👂","👀","👃","👅","👄","👍","👎","👌","👊","✊",
		"✌","👋","✋","👐","👆","👇","👉","👈","🙌","🙏","☝",
		"👏","💪","🚶","🏃","💃","👫","👪","👬","👭","💏","💑",
		"👯","🙆","🙅","💁","🙋","💆","💇","💅","👰","🙎","🙍",
		"🙇","🎩","👑","👒","👟","👞","👡","👠","👢","👕","👔",
		"👚","👗","🎽","👖","👘","👙","💼","👜","👝","👛","👓",
		"🎀","🌂","💄","💛","💙","💜","💚","❤","💔","💗","💓",
		"💕","💖","💞","💘","💌","💋","💍","💎","👤","👥","💬",
		"👣","💭"
	);

    public static void main(String[] args){
        long start = System.nanoTime();
        
        ForkJoinPool pool = new ForkJoinPool();
        
        for (String name: Arrays.asList("temp1","temp2","temp3","temp4","temp5")){
            pool.invoke(new IOByFJ(name, Integer.valueOf(args[0])));
        };

        long end = System.nanoTime();
        System.out.println(end-start);
        
    }

}

RecursiveByExec.java

import java.util.concurrent.*;

public class RecursiveByExec implements Callable<Integer>{
    
    private final int n;
    private ExecutorService exec = Executors.newCachedThreadPool();
    
    public RecursiveByExec(int n){
        this.n = n;
    }
    
    public Integer call() throws Exception{
        if(n <= 1){
            return n;
        }
        Future<Integer> f1 = exec.submit(new RecursiveByExec(n-1));
        Future<Integer> f2 = exec.submit(new RecursiveByExec(n-2));
        return f1.get() + f2.get();
    }
    
    public void doExecute(){
        try{
            Future<Integer> f =  exec.submit(this);
            System.out.println(f.get());
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            exec.shutdown();
        }
    }
    
    public static void main(String[] args){
        long start = System.nanoTime();
        
        RecursiveByExec rec = new RecursiveByExec(Integer.valueOf(args[0]));
        rec.doExecute();
    
        long end = System.nanoTime();
        System.out.println(end-start);
    }
}

RecursiveByFJ.java

import java.util.concurrent.*;

public class RecursiveByFJ extends RecursiveTask<Integer>{
    
    private final int n;
    
    public RecursiveByFJ(int n){
        this.n = n;
    }
    
    @Override
    public Integer compute(){
        if(this.n <= 1){
            return n;
        }
        
        RecursiveByFJ r1 = new RecursiveByFJ(n-1);
        r1.fork();
        RecursiveByFJ r2 = new RecursiveByFJ(n-2);
        return r2.compute() + r1.join();
    }

    // フィボナッチ数列における任意番目の値を返す。
    public static void main(String[] args){
        long start = System.nanoTime();
        
        ForkJoinPool pool = new ForkJoinPool();
        System.out.println(pool.invoke(new RecursiveByFJ(Integer.valueOf(args[0]))));
        
        long end = System.nanoTime();
        System.out.println(end-start);
        
    }

}