Run multi-thread at a time and make thread to run fast

Question

I am trying to run two different threads at a time, but unable to do that. Thread_1 & Thread_2 runs, but difference between them is around 500ms. I am not using wait() or sleep() anywhere in my code.

Questions:

How to make run thread simultaneously or in parallel?
How to make thread run fast?

For second question this I used Thread.setPriority(Thread.MAX_PRIORITY) but time difference between other is same.

Updated with example code

Doing same as below example, but takes more time between both threads to run.

public static void main(String args[])
{
    MyThread thread1 = new MyThread("thread1: ");
    MyThread thread2 = new MyThread("thread2: ");
    thread1.start();
    thread2.start();
    boolean thread1IsAlive = true;
    boolean thread2IsAlive = true;
    do {
       if (thread1IsAlive && !thread1.isAlive()) {
           thread1IsAlive = false;
            System.out.println("Thread 1 is dead.");
       }
       if (thread2IsAlive && !thread2.isAlive()) {
           thread2IsAlive = false;
           System.out.println("Thread 2 is dead.");
       }
    } while(thread1IsAlive || thread2IsAlive);
}

I have searched the web and gone through some docs. What can I try next?

Post the code, we can help you with your problem without seeing what you are doing. — Jesper Fyhr Knudsen, Dec 06 '12 at 12:14
@Arkain I dint post my code, but for example look at this code.I am trying exactly same — Rahul Baradia, Dec 06 '12 at 12:25
Not running the create/monitor thread as a do..while CPU loop may well help... — Martin James, Dec 06 '12 at 12:29

score 2 · Accepted Answer · edited May 23 '17 at 10:34

2

How to make run thread simultaneously or in parallel?

As a programmer it's only possible on multi processor machines. On single processor only one thread will run at one time and it's upto JVM (and OS) to choose which thread to run.

How to make thread run fast ?

You can try (as you did), but overall control is with JVM (and OS) only.

However, increasing the priority of thread doesn't mean that it'll run fast. it only makes chances for the thread to run more frequently than other threads. i.e. OS may (or may not)choose it more no. of times than other threads.

Go through this link for some more details. Check this too.

edited May 23 '17 at 10:34

Community

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answered Dec 06 '12 at 12:14

Azodious

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your right, depends on OS but there can be a way to handle it. – Rahul Baradia Dec 06 '12 at 12:18
Technically true that only one thread can be run at a time on a single core CPU, however the OS will switch between all threads rapidly, which give the illusion of parallel execution. – Jesper Fyhr Knudsen Dec 06 '12 at 12:18
yup. Technically your right. depends on OS how it run the thread. I tried using CyclicBarrier . Then too dint get it – Rahul Baradia Dec 06 '12 at 12:21
@TechEnd: unfortunately (or fortunately) there is not. it's JVM and OS's call entirely. – Azodious Dec 06 '12 at 12:23
yup.. your right sir. Then too make run thread faster what else I can try ?? – Rahul Baradia Dec 06 '12 at 12:27
Stop wasting one core on monitoring? – Martin James Dec 06 '12 at 12:30
run only your program on system. – Azodious Dec 06 '12 at 12:30

score 1 · Answer 2 · answered Dec 06 '12 at 12:14

1

You can't be sure about it nor you can do it.You call thread.start() to start a thread.But it depends on OS when it will be started.Even with setting priority you can't exactly achieve this.

answered Dec 06 '12 at 12:14

Rasel

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I am calling Thread_1.start() and Thread_1.start() simultaneously to run. But difference between both timing I want to remove it. – Rahul Baradia Dec 06 '12 at 12:15
You can't do this.Because OS defines when and how thread will be executed.You can pass your idea to os by setting priority that one has priority over other.But OS defines what it would do. – Rasel Dec 06 '12 at 12:17
ohk.. then there is no other way to do this ?? – Rahul Baradia Dec 06 '12 at 12:19

Run multi-thread at a time and make thread to run fast

Updated with example code

2 Answers2