What is thread safety?

Question

Hey
Can anyone tell me what is thread safety? I can't understand it
Thanks to all

Answer 1

thread-safety  refers to code which can safely be used or shared in concurrent or multi-threading environment and they will behave as expected. any code, class, or object which can behave differently from its contract on the concurrent environment is not thread-safe.

check these two examples below :

/*

 * Thread-Safe Example in Java

 */
public class Counter {
    private int count;
    AtomicInteger atomicCount = new AtomicInteger( 0 )
    /*
     * This method thread-safe now because of locking and synchornization
     */
    public synchronized int getCount(){
        return count++;

    }
    /*

     * This method is thread-safe because count is incremented atomically

     */

    public int getCountAtomically(){

        return atomicCount.incrementAndGet();

    }

}

check non safe:

/*

 * Non Thread-Safe Class in Java

 */
public class Counter {
    private int counts
    /*
     * This method is not thread-safe because ++ is not an atomic operation

Answer 2

Thank you a lot