How does the division and simultaneous execution of tasks on CPU cores occur?

In Java, multithreading and parallel programming are used to perform tasks simultaneously on multiple processor cores. The JVM creates several threads that can run concurrently on different cores if supported by the operating system and hardware platform.

Main mechanisms:

• Thread Pool — a set of pre-created threads that are reused to execute tasks, reducing the overhead of creating new threads.
• Fork/Join Framework — allows splitting tasks into subtasks and executing them in parallel, efficiently utilizing all cores.
• Parallel Streams — simplify parallel processing of collections.

Example of using a thread pool:

ExecutorService executor = Executors.newFixedThreadPool(4); // 4 threads
for (int i = 0; i < 10; i++) {
    int taskId = i;
    executor.submit(() -> {
        System.out.println("Task " + taskId + " is running in thread " + Thread.currentThread().getName());
    });
}
executor.shutdown();

Tasks will be distributed among threads and executed in parallel on available cores.