CODEWITHSUNDEEP
javamultithreadingthreadpool
Abdo Bmz
Abdo Bmz

Reputation: 641

When to use a Thread and when to use a Threadpool?

Can anyone guide me in this Example Thread and ThreadPool What is the difference between them? Which is better to use ...? What is the drawback on ?

I used a threadpool and why use it in this case true or false ? 

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

class ThreeThread implements Runnable {

    String c;
    Semaphore s1;
    Semaphore s2;

    public ThreeThread(String s, Semaphore s1, Semaphore s2) {
        this.c = s;
        this.s1 = s1;
        this.s2 = s2;
    }

    @Override
    public void run() {
        while (true) {
            try {
                s1.acquire();
                Thread.sleep(400);
                System.out.println(c);
                s2.release();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                System.out.println(e);
            }
        }
    }

    public static void main(String[] args) {
        Semaphore sm1 = new Semaphore(1);
        Semaphore sm2 = new Semaphore(0);
        Semaphore sm3 = new Semaphore(0);

        ExecutorService es = Executors.newFixedThreadPool(3);

        es.execute(new ThreeThread("1", sm1, sm2));
        es.execute(new ThreeThread("2", sm2, sm3));
        es.execute(new ThreeThread("3", sm3, sm1));
    }
}

Upvotes: 3

Views: 3823

Answers (3)

Umy Angel
Umy Angel

Reputation: 61

when to use: Threads: I want to manage thread creation, decide time of creation, and monitor, synchronization, thread cleanup, myself.

Executor: I want specialist/manager to perform these activities.

Upvotes: -1

Kaka
Kaka

Reputation: 1

Well, I thought that a ThreadPoolExecutor provided better performance for it manages a pool of threads, minimizing the overhead of instantiating a new thread, allocating memory...

And if you are going to launch thousands of threads, it gives you some queuing functionality you would have to program by yourself...

Threads & Executors are different tools, used on different scenarios... As I see it, is like asking why should I use ArrayList when I can use HashMap? They are different...

Upvotes: -1

xingbin
xingbin

Reputation: 28269

See the doc of ThreadPoolExecutor:

Thread pools address two different problems:

they usually provide improved performance when executing large numbers of asynchronous tasks, due to reduced per-task invocation overhead,

and they provide a means of bounding and managing the resources, including threads, consumed when executing a collection of tasks.

Each ThreadPoolExecutor also maintains some basic statistics, such as the number of completed tasks.

Upvotes: 5

Related Questions