io.netty.util

Class ThreadDeathWatcher

java.lang.Object

io.netty.util.ThreadDeathWatcher

public final class ThreadDeathWatcher
extends Object

Checks if a thread is alive periodically and runs a task when a thread dies.

This thread starts a daemon thread to check the state of the threads being watched and to invoke their associated Runnables. When there is no thread to watch (i.e. all threads are dead), the daemon thread will terminate itself, and a new daemon thread will be started again when a new watch is added.

Method Summary

Modifier and Type	Method and Description
static boolean	awaitInactivity(long timeout, TimeUnit unit) Waits until the thread of this watcher has no threads to watch and terminates itself.
static void	unwatch(Thread thread, Runnable task) Cancels the task scheduled via watch(Thread, Runnable).
static void	watch(Thread thread, Runnable task) Schedules the specified task to run when the specified thread dies.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

watch

public static void watch(Thread thread,
                         Runnable task)

Schedules the specified task to run when the specified thread dies.

Parameters:

thread - the Thread to watch

task - the Runnable to run when the thread dies

Throws:

IllegalArgumentException - if the specified thread is not alive

unwatch

public static void unwatch(Thread thread,
                           Runnable task)

Cancels the task scheduled via watch(Thread, Runnable).

awaitInactivity

public static boolean awaitInactivity(long timeout,
                                      TimeUnit unit)
                               throws InterruptedException

Waits until the thread of this watcher has no threads to watch and terminates itself. Because a new watcher thread will be started again on watch(Thread, Runnable), this operation is only useful when you want to ensure that the watcher thread is terminated after your application is shut down and there's no chance of calling watch(Thread, Runnable) afterwards.

Returns:

true if and only if the watcher thread has been terminated

Throws:

InterruptedException