thread - join()

[anitha.s]

What is the use join() method in Thread class?

[muralipn]

Hi

When the join() method is called, the current thread will simply wait until
the thread it is joining with is no longer alive. This can be caused by
the thread not having been started, or having been stopped by yet another
thread, or by the completion of the thread itself. The join() method
basically accomplishes the same task as the combination of the sleep() and
isAlive() methods. However, by using the join() method, we accomplish
the same task with a single method call. We also have better control over the timeout interval, and we don't have to waste CPU cycles by polling.

There are three versions of the join method:

void join()
Waits for the completion of the specified thread. By definition,
join() returns as soon as the thread is considered "not alive". This
includes the case in which the join() method is called on a thread
that has not been started.

void join(long timeout)
Waits for the completion of the specified thread, but no longer
than the timeout specified in milliseconds. This timeout value is
subject to rounding based on the capabilities of the underlying
platform.

void join(long timeout, int nanoseconds)
Waits for the completion of the specified thread, but no longer
than a timeout specified in milliseconds and nanoseconds. This
timeout value is subject to rounding based on the capabilities
of the underlying platform.

Regards,
Murali

[anitha.s]

Thanks