package com.kartik;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;
public class ThreadBaseMultitasking {
/**
* Maximum amount of numbers to check
*/
public static final int MAX_NUMBER = 2000000000;
/**
* Returns the amount of numbers that can be divided by the divisor without remainder.
* @param first First number to check
* @param last Last number to check
* @param divisor Divisor
* @return Amount of numbers that can be divided by the divisor without remainder
*/
public static int totalTaskExecution(int first, int last, int divisor) {
int amount = 0;
for (int i = first; i <= last; i++) {
if (i % divisor == 0) {
amount++;
}
}
return amount;
}
/**
* Returns the amount of numbers that can be divided by the divisor without remainder (using parallel execution).
* @param first First number to check
* @param last Last number to check
* @param divisor Divisor
* @return Amount of numbers that can be divided by the divisor without remainder
* @throws InterruptedException
* @throws ExecutionException
*/
public static int totalTaskExecutionByNumberOfPoolThreadwise(final int first, final int last, final int divisor)
throws InterruptedException, ExecutionException {
int amount = 0;
// Prepare to execute and store the Futures
int threadNum = 2;
ExecutorService executor = Executors.newFixedThreadPool(threadNum);
List<FutureTask<Integer>> taskList = new ArrayList<FutureTask<Integer>>();
// Start thread for the first half of the numbers
FutureTask<Integer> futureTask_1 = new FutureTask<Integer>(new Callable<Integer>() {
@Override
public Integer call() {
return ThreadBaseMultitasking.totalTaskExecution(first, last / 2, divisor);
}
});
taskList.add(futureTask_1);
executor.execute(futureTask_1);
// Start thread for the second half of the numbers
FutureTask<Integer> futureTask_2 = new FutureTask<Integer>(new Callable<Integer>() {
@Override
public Integer call() {
return ThreadBaseMultitasking.totalTaskExecution(last / 2 + 1, last, divisor);
}
});
taskList.add(futureTask_2);
executor.execute(futureTask_2);
// Wait until all results are available and combine them at the same time
for (int j = 0; j < threadNum; j++) {
FutureTask<Integer> futureTask = taskList.get(j);
amount += futureTask.get();
}
executor.shutdown();
return amount;
}
/**
* Executing the example.
* @param args Command line arguments
* @throws ExecutionException
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException, ExecutionException {
// Sequential execution
long timeStart = Calendar.getInstance().getTimeInMillis();
int result = ThreadBaseMultitasking.totalTaskExecution(0, MAX_NUMBER, 3);
long timeEnd = Calendar.getInstance().getTimeInMillis();
long timeNeeded = timeEnd - timeStart;
System.out.println("Result : " + result + " calculated in " + timeNeeded + " ms");
// Parallel execution
long timeStartFuture = Calendar.getInstance().getTimeInMillis();
int resultFuture = ThreadBaseMultitasking.totalTaskExecutionByNumberOfPoolThreadwise(0, MAX_NUMBER, 3);
long timeEndFuture = Calendar.getInstance().getTimeInMillis();
long timeNeededFuture = timeEndFuture - timeStartFuture;
System.out.println("Result (Future): " + resultFuture + " calculated in " + timeNeededFuture + " ms");
}
}
Out put :
Result : 666666667 calculated in 10762 ms
Result (Future): 666666667 calculated in 6514 ms
I am Kartik Chandra Mandal from Bangalore, India. Working as software engineer in Java technology. Have good knowledge of OWASP and CSRF in security for applications and it's implementation in Java technology.