package sync;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Semaphore;

public class Test

$\{$

$$public static void main

$($

String

$[$

$]$

$$args

$)$

$\{$

$$ ExecutorService executorService

$=$

$$Executors$.$newCachedThreadPool

$($

$)$

;

$$ ReadWriteLock RW

$=$

$$new ReadWriteLock

$($

$)$

;

$$ executorService.execute

$($

new Writer

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Writer

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Writer

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Writer

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Reader

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Reader

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Reader

$($

RW

$)$

$)$

;

$$ executorService.execute

$($

new Reader

$($

RW

$)$

$)$

;

$$

$\}$

$\}$

class ReadWriteLock

$\{$

$$private Semaphore S

$=$

new Semaphore

$($

$1$

$)$

;

$$public void readLock

$($

$)$

$\{$

$$

$\}$

$$public void writeLock

$($

$)$

$\{$

$$

$\}$

$$public void readUnLock

$($

$)$

$\{$

$$

$\}$

$$public void writeUnLock

$($

$)$

$\{$

$$

$\}$

$\}$

class Writer implements Runnable

$\{$

$$ private ReadWriteLock RW

$\_$

lock;

$$ public Writer

$($

ReadWriteLock rw

$)$

$\{$

$$ RW

$\_$

lock

$=$

$$rw;

$$

$\}$

$$ public void run

$($

$)$

$\{$

$$ while

$($

true

$)$

$\{$

$$ RW

$\_$

lock.writeLock

$($

$)$

;

$$ RW

$\_$

lock.writeUnLock

$($

$)$

;

$$

$\}$

$$

$\}$

$\}$

class Reader implements Runnable

$\{$

$$ private ReadWriteLock RW

$\_$

lock;

$$ public Reader

$($

ReadWriteLock rw

$)$

$\{$

$$ RW

$\_$

lock

$=$

$$rw;

$$

$\}$

$$ public void run

$($

$)$

$\{$

$$ while

$($

true

$)$

$\{$

$$ RW

$\_$

lock.readLock

$($

$)$

;

$$ RW

$\_$

lock.readUnLock

$($

$)$

;

$$

$\}$

$$

$\}$

$\}$

$$

this is the test.java mentioned in the question.