Daemon Thread

Question

Hi buddies, What is Daemon Thread in java? Please give an example of Daemon Thread. Thanks!

Rijwan Ansari · Answer

Daemon thread is a low priority thread (in context of JVM) that runs in background to perform tasks such as garbage collection (gc) etc., they do not prevent the JVM from exiting (even if the daemon thread itself is running) when all the user threads (non-daemon threads) finish their execution. Example: public class DaemonThreadExample1 extends Thread{ public void run(){ // Checking whether the thread is Daemon or not if (Thread.currentThread().isDaemon()){ System.out.println( "Daemon thread executing" ); } else { System.out.println( "user(normal) thread executing" ); } } public static void main(String[] args){ /* Creating two threads: by default they are * user threads (non-daemon threads) */ DaemonThreadExample1 t1= new DaemonThreadExample1(); DaemonThreadExample1 t2= new DaemonThreadExample1(); //Making user thread t1 to Daemon t1.setDaemon( true ); //starting both the threads t1.start(); t2.start(); } } Output Daemon thread executing user(normal) thread executing Reference https://beginnersbook.com/2015/01/daemon-thread-in-java-with-example/

Satya Karki · Answer

Daemon thread in Java is a service provider thread that provides services to the user thread. Its life depend on the mercy of user threads i.e. when all the user threads dies, JVM terminates this thread automatically.

Daril · Answer

The daemon threads function is to provide services to the user threads. These threads have low priority. The high priority threads are the user threads. They are called only when the user threads are running. They are mostly used for garbage collection like clearing garbage cache memory. The thread that is created will inherit the created thread's daemon status. After creating a thread object we can call the daemon method. And also the thread should be idle

Aarti · Answer

In Java, any thread can be a Daemon thread. Daemon threads are like a service providers for other threads or objects running in the same process as the daemon thread. Daemon threads are used for background supporting tasks and are only needed while normal threads are executing. If normal threads are not running and remaining threads are daemon threads then the interpreter exits. setDaemon(true/false) ? This method is used to specify that a thread is daemon thread. public boolean isDaemon() ? This method is used to determine the thread is daemon thread or not. The following program demonstrates the Daemon Thread: public class DaemonThread extends Thread { public void run() { System.out.println("Entering run method"); try { System.out.println("In run Method: currentThread() is" + Thread.currentThread()); while (true) { try { Thread.sleep(500); } catch (InterruptedException x) { } System.out.println("In run method: woke up again"); } } finally { System.out.println("Leaving run Method"); } } public static void main(String[] args) { System.out.println("Entering main Method"); DaemonThread t = new DaemonThread(); t.setDaemon(true); t.start(); try { Thread.sleep(3000); } catch (InterruptedException x) { } System.out.println("Leaving main method"); }

Sam Hobbs · Answer

The term Daemon is a Unix term; Windows does not use that term. I believe that in Unix a Daemon is what Windows calls a service, but I am not sure. So you really should have more context for your question. If this is a class assignment question, then you just need to do some reading. If you need an answer in the context of .Net or the wider context of Windows then you need to clarify your question.

Guest User · Answer

Umm... I'm not sure how many Java experts you're going to find at a C#.Net site, but in any event, Google is your friend .

Daemon Thread

Answers (6)