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javamultithreadingdaemon

Daemon Thread more than one?

This is a very short and simple question, but couldn't get the answer from anywhere.

More than one daemon threads can be created?

Solution

  • Yes. You can simply test it with code like

    Thread t1 = new Thread(()->{
    while(true){
        System.out.println("daemon1");
        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (Exception e) {}
    }
});
t1.setDaemon(true);

Thread t2 = new Thread(()->{
    while(true){
        System.out.println("daemon2");
        try {
            TimeUnit.SECONDS.sleep(2);
        } catch (Exception e) {}
    }
});
t2.setDaemon(true);

t1.start();
t2.start();

try {
    TimeUnit.SECONDS.sleep(5);
} catch (Exception e) {}
System.out.println("main thread stopped");

    Output:

    daemon1
daemon2
daemon1
daemon2
daemon1
daemon1
daemon1
daemon2
daemon1
main thread stopped

    As you see two daemons ware running at the same time. Also since there ware no other non-daemon threads, application stopped.