[Java] Daemon Thread

Daemon Thread

- Daemon Thread is a service provider thread that provides services to the user thread

- Its life depend on the mercy of user thread i.e. all the user threads dies, JVM terminates this thread automatically

- gc, finalizer etc..

1. Points to remember for Daemon Thread

- It provides services to user threads for background supporting tasks

- Its life depends on user thread

- It is a low priority thread

2. Why JVM terminates the daemon thread if there is no user thread?

- The sole purpose of the daemon thread is that it provides services to user thread for background supporting task

- If there is no user thread, we don't need daemon threads

3. Methods for Daemon thread by Thread class

1) public void setDaemon(boolean status)

- It is used to mark the current thread as daemon thread or user thread

2) public boolean isDaemon()

- It is used to check that current is daemon

4. Example

public class Daemon extends Thread{ public void run(){ if(Thread.currentThread().isDaemon()){ System.out.println("daemon thread"); }else{ System.out.println("user thread"); } } public static void main(String[]args){ Daemon t1 = new Daemon(); Daemon t2 = new Daemon(); Daemon t3 = new Daemon(); t1.setDaemon(true); t1.start(); t2.start(); t3.start(); } }