The document describes the life cycle of a thread, which includes states such as new, runnable, waiting, timed waiting, and terminated. It explains how threads transition between these states, emphasizing the role of object.wait method and monitor acquisition. Additionally, it mentions the blocked state when multiple threads contend for the same monitor, with only one thread successfully obtaining it.

1. A thread goes through various stages in its life cycle.
e.g, a thread is born, started, runs, and then dies.

2. life cycle of a thread

3. 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.

4. Runnable
After a newly born thread is started, the thread becomes
runnable. A thread in this state is considered to be
executing its task.

5. Waiting
Sometimes, a thread transitions to the waiting state while
the thread waits for another thread to perform a task.
A thread transitions back to the runnable state only when
another thread signals the waiting thread to continue
executing.

6. Timed waiting
A runnable thread can enter the timed waiting state for a
specified interval of time.
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.

7. Terminated
A runnable thread enters the terminated state when it
completes its task or otherwise terminates.

8. Object.wait method
When a thread calls Object.wait method, it releases all
the acquired monitors and is put into WAITING or
TIMED_WAITING.
Now when the thread is notified either by notify( ) or
by notifyAll ( ) call on the same object then the waiting
state of the thread ends and the thread starts attempting
to regain all the monitors which it had acquired at the
time of wait call.

9. BLOCKED state
At one time there may be several threads trying to regain
their monitors.
If more than one threads attempt to acquire the monitor
of a particular object then only one thread is granted the
monitor and all other threads are put into BLOCKED
state.