What is the idea of multithreading?

The idea of multithreading is to execute multiple parts of a program (threads) simultaneously or nearly simultaneously within a single process to improve performance and resource utilization.

Main aspects:

• Parallelism: On multiprocessor systems, threads can be executed physically in parallel.
• Concurrency: On single-processor systems, threads are interleaved, creating the illusion of parallelism through rapid context switching.
• Shared resources: Threads within a single process share memory and other resources, which requires synchronization to prevent issues such as race conditions.
• Responsiveness: Allows long-running operations to be performed in a background thread without blocking the main user interface thread.

Example of creating a thread in Java:

// Creating a thread by inheriting from the Thread class
class MyThread extends Thread {
    @Override
    public void run() {
        System.out.println("Thread is running.");
    }
}

// ... elsewhere in the code
MyThread thread = new MyThread();
thread.start(); // Starting the thread

Or using the Runnable interface:

// Creating a thread by implementing the Runnable interface
class MyRunnable implements Runnable {
    @Override
    public void run() {
        System.out.println("Task is running in the thread.");
    }
}

// ... elsewhere in the code
Thread thread = new Thread(new MyRunnable());
thread.start(); // Starting the thread