Deeper look into Java threads:

Category : Java | Sub Category : Java Threads | By Prasad Bonam Last updated: 2023-08-15 11:20:32 Viewed : 313

Java threads are the basic units of execution in Java that allow you to perform multiple tasks concurrently within a single program. Threads enable you to execute code in parallel, making use of available CPU resources efficiently and enabling applications to handle multiple tasks simultaneously.

Here is a deeper look into Java threads:

1. Creating Threads:

You can create threads in Java by either extending the Thread class or implementing the Runnable interface.

a. Extending Thread class:

javaCopy code
class MyThread extends Thread {
    public void run() {
        System.out.println("Thread is running");
    }
}

public class ThreadExample {
    public static void main(String[] args) {
        MyThread thread = new MyThread();
        thread.start(); // Starts the threads execution
    }
}

b. Implementing Runnable interface:

javaCopy code
class MyRunnable implements Runnable {
    public void run() {
        System.out.println("Thread is running");
    }
}

public class ThreadExample {
    public static void main(String[] args) {
        MyRunnable runnable = new MyRunnable();
        Thread thread = new Thread(runnable);
        thread.start();
    }
}

2. Thread Lifecycle:

Threads go through various states during their lifecycle:

• New: A thread is created but not yet started.
• Runnable: The thread is ready to run, and its waiting for CPU resources.
• Running: The thread is actively executing its code.
• Blocked/Waiting: The thread is temporarily not executing due to reasons like waiting for I/O operations, synchronization, etc.
• Terminated: The thread has completed its execution.

3. Synchronization:

When multiple threads access shared resources, synchronization is needed to avoid data inconsistency and race conditions. You can use synchronized blocks/methods to ensure mutual exclusion.

javaCopy code
class Counter {
    private int count = 0;

    public synchronized void increment() {
        count++;
    }

    public int getCount() {
        return count;
    }
}

4. Thread States:

Java threads can have several states: NEW, RUNNABLE, BLOCKED, WAITING, TIMED_WAITING, and TERMINATED. These states reflect the threads current state of execution and synchronization.

5. Thread Priority:

Java threads have priority levels ranging from 1 (lowest) to 10 (highest). You can use the setPriority() method to set a threads priority. However, priority alone might not ensure a specific execution order due to platform variations.

6. Daemon Threads:

Daemon threads are background threads that are created to perform tasks that should not prevent the program from exiting. They automatically terminate when all non-daemon threads finish.

7. Thread Pooling:

Creating too many threads can have performance implications. Thread pooling using Javas ExecutorService can help manage and reuse threads efficiently.

Java provides extensive support for multithreading through its java.lang.Thread class, synchronization mechanisms, and higher-level concurrency utilities. Its essential to understand the concepts of thread safety, synchronization, and the proper use of threading mechanisms to write efficient and robust multithreaded applications.