Q. What is daemon thread in Java with example?
26 Answers. A daemon thread is a thread that does not prevent the JVM from exiting when the program finishes but the thread is still running. An example for a daemon thread is the garbage collection. You can use the setDaemon(boolean) method to change the Thread daemon properties before the thread starts.
Q. Is main thread a daemon thread in Java?
2 Answers. The main thread cannot be set as daemon thread. Because a thread can be set daemon before its running and as soon as the program starts the main thread starts running and hence cannot be set as daemon thread. Marks this thread as either a daemon thread or a user thread.
Q. What are daemon threads and how it can be created what are its features?
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. There are many java daemon threads running automatically e.g. gc, finalizer etc.
Q. What is ThreadGroup in Java?
ThreadGroup creates a group of threads. The thread group form a tree in which every thread group except the initial thread group has a parent. A thread is allowed to access information about its own thread group but not to access information about its thread group’s parent thread group or any other thread group.
Q. Is Garbage Collector A daemon thread?
How GC works. Java Garbage Collector runs as a Daemon Thread (i.e. a low priority thread that runs in the background to provide services to user threads or perform JVM tasks).
Q. What is Diamond thread in Java?
Daemon thread is a low priority thread that runs in background to perform tasks such as garbage collection. Properties: They can not prevent the JVM from exiting when all the user threads finish their execution. If JVM finds running daemon thread, it terminates the thread and after that shutdown itself.
Q. How can we create daemon threads?
Creating a thread as a daemon in Java is as simple as calling the setDaemon() method. A setting of true means the thread is a daemon; false means it is not. By default, all threads are created with an initial value of false.
Q. What is shutdown hook in Java?
Shutdown Hooks are a special construct that allows developers to plug in a piece of code to be executed when the JVM is shutting down. This comes in handy in cases where we need to do special clean up operations in case the VM is shutting down.
Q. Can we create our own daemon thread?
Q. What is difference between Daemon and non daemon thread?
Difference between Daemon and Non Daemon (User Threads) is that: JVM waits for non-daemon threads to finish executing before terminate the main program. On the other hand, JVM doesn’t wait for daemon thread to finish.
Q. How many types of thread in Java?
There are only two types of thread in Java, daemon and non-daemon, and only one simple difference between them. That difference has been explained here, and is explained in the API.
Q. Is main thread is a daemon thread?
Any thread created by main thread, which runs main method in Java is by default non daemon because Thread inherits its daemon nature from the Thread which creates it i.e. parent Thread and since main thread is a non daemon thread, any other thread created from it will remain non-daemon until explicitly made daemon by calling setDaemon (true).
Q. Is thread scheduler part of JVM or OS?
Thread scheduler in java is the part of the JVM that decides which thread should run. There is no guarantee that which runnable thread will be chosen to run by the thread scheduler. Only one thread at a time can run in a single process. The thread scheduler mainly uses preemptive or time slicing scheduling to schedule the threads.
