Life cycle of a thread in Java

The life cycle of a thread in java is controlled by JVM. A thread goes through various stages in its lifecycle. For example, a thread is born, started, runs, and then dies. The following diagram shows the complete life cycle of a thread.

The java thread states are as follows:

1. New
2. Runnable
3. Blocked
4. Waiting
5. Timed Waiting
6. Terminated

• New − A new thread begins its life cycle in the new state. It remains in this state until the program starts the thread. It is also referred to as a born thread.
•  Runnable − After a newly born thread is started, the thread becomes runnable. A thread in this state is considered to be either running or ready for execution but it’s waiting for resource allocation
• Blocked – waiting to acquire a monitor lock to enter or re-enter a synchronized block/method
•  Waiting − Sometimes, a thread transitions to the waiting state while the thread waits for another thread to perform a task. Thread transitions back to the runnable state only when another thread signals the waiting thread to continue executing.
•  Timed Waiting − Waiting for some other thread to perform a specific action for a specified period. A thread in this state transitions back to the runnable state when that time interval expires or when the event it is waiting for occurs.
•  Terminated (Dead) − A runnable thread enters the terminated state when it completes its task or otherwise terminates.