Code to see that a class is not thread safe

[mental monolith]

I have attached the question that I am answering for not thread safe class. The output changes after multiple runs
This is my code for testing if a class is not thread safe.

public class AddThread implements Runnable {
    private CardDeck seq;
    private int input;
    
    public AddThread(int input, CardDeck deck){
        this.input =input;
        this.seq=deck;
    }
    
    public void run() {
        for (int i=0;i<input;i++){
            seq.dealCard();
        }
    }

public class SimpleThreads {
    public static void main(String[] args) throws InterruptedException{
        CardDeck deck = new CardDeck();

        AddThread t1 = new AddThread(20000, deck);
        AddThread t2 = new AddThread(40000, deck);

        Thread Th1 = new Thread(t1);
        Thread Th2 = new Thread(t2);
        Th1.start();
        Th2.start();
        Th1.join();
        Th2.join();

        System.out.println(deck.sequenceNumber);
    }
}

public class UnSafeSequence {
    private int value = 0;
    public int[] sequenceNumber;
    public int dealCard(){
        return value++;
    }
    public int getResult(){
        return value;
    }
}

[harsh token]

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[polar garden]

okay?

[mental monolith]

??

are you going to help?

[polar garden]

Possibly. Do you need help?

[mental monolith]

yes please

i'm trying to show carddeck is not thread safe

but my code that I have doesn't fully work

[polar garden]

What do you mean?

Ideally, you'd explain what you mean before being asked, and before asking for help

[mental monolith]

so i'm trying to show that the class carddeck is not thread safe. Not thread safe basically means there a different output each time the code is being run.
To do this I made a this code

public class AddThread implements Runnable {
    private CardDeck seq;
    private int input;
    
    public AddThread(int input, CardDeck deck){
        this.input =input;
        this.seq=deck;
    }
    
    public void run() {
        for (int i=0;i<input;i++){
            seq.dealCard();
        }
    }
    
}

public class SimpleThreads {
    public static void main(String[] args) throws InterruptedException{
        CardDeck deck = new CardDeck();

        AddThread t1 = new AddThread(20000, deck);
        AddThread t2 = new AddThread(40000, deck);

        Thread Th1 = new Thread(t1);
        Thread Th2 = new Thread(t2);
        Th1.start();
        Th2.start();
        Th1.join();
        Th2.join();
        
        System.out.println(deck.sequenceNumber);
    }
}

public class UnSafeSequence {
    private int value = 0;
    public int[] sequenceNumber;
    public int dealCard(){
        return value++;
    }
    public int getResult(){
        return value;
    }
}

My code sometimes gives the same output so it's not showing the correct result

[polar garden]

Stop repeating and just explain yourself

[mental monolith]

???

[polar garden]

repeating is saying the same stuff again. That's not useful because you already said it. So don't do that

[mental monolith]

:/

[polar garden]

Instead you should use words that make it so people can get an idea of what is your situation, rather than words that make it unlikely they would

[mental monolith]

:/

[polar garden]

Most likely:
"My code sometimes gives the same output so it's not showing the correct result"
You should be able to realize that you should have never written such a sentence, or at least not without examples that show what happens

In other words, just be a person capable of communication

So:
What do you mean?

[mental monolith]

idk anymore

[bold thorn]

at least honestly

[mental monolith]

:/