This class
synchronizes
threads. All threads that call await( ) block
until the countDown( ) method is invoked a
specified number of times. The required number of calls is specified
when the CountDownLatch is created. Once
countDown( ) has been called the required number
of times, all threads blocked in await( ) are
allowed to resume, and any subsequent calls to await(
) do not block. getCount( ) returns the
number of calls to countDown( ) that must still be
made before the threads blocked in await( ) can
resume. Note that there is no way to reset the count. Once a
CountDownLatch has
"latched," it remains in that state
forever. Create a new CountDownLatch if you need
to synchronize another group of threads. Contrast this class with
CyclicBarrier.
public class
CountDownLatch {
// Public Constructors
public
CountDownLatch (int
count );
// Public Instance Methods
public void
await ( ) throws InterruptedException;
public boolean
await (long
timeout , TimeUnit
unit ) throws InterruptedException;
public void
countDown ( );
public long
getCount ( );
// Public Methods Overriding Object
public String
toString ( );
}