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Multithreading

Multithreading in java is a process of executing multiple threads simultaneously. Usually used in games.

There are two ways of creating a Thread.

By extending Thread class​

class MultiClass extends Thread {

    public void run() {
        System.out.println("thread method started…");
    }

    public static void main(String args[]) {
        MultiClass t1=new MultiClass ();
        t1.start();
    }
}

By implementing Runnable interface​

class MultiClass implements Runnable {

    public void run() {
        System.out.println("Thread is running...");
    }

    public static void main(String args[]) {
        MultiClass mc1=new MultiClass ();
        Thread t1 =new Thread(mc1);
        t1.start();
    }
}

Synchronization​

In multi-threaded environment, if we need to make a resource available to one thread at a time, we use synchronization. The synchronization keyword in java creates a block of code called critical section (which can be used by only one thread at a time using lock).

Inter process communication​

Two or more threads can interact with each other using three methods such as

  • wait() (Release the lock & make the thread suspended)
  • notify() (Release the lock & Resumes a thread which is suspended)
  • notifyAll() (Release the lock & Resumes all thread which are suspended)