Package org.apache.hadoop.util

Class Daemon

java.lang.Object

java.lang.Thread

org.apache.hadoop.util.Daemon

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

Daemon.DaemonFactory

@LimitedPrivate({"HDFS","MapReduce"})
@Unstable
public class Daemon
extends Thread

A thread that has called Thread.setDaemon(boolean) with true.

The runnable code must either be specified in the runnable parameter or in the overridden work() method.

See SubjectInheritingThread for the Subject inheritance behavior this class adds.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Daemon.DaemonFactory	Provide a factory for named daemon threads, for use in ExecutorServices constructors

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor	Description
Daemon()	Construct a daemon thread.
Daemon(Runnable runnable)	Construct a daemon thread.
Daemon(ThreadGroup group, Runnable runnable)	Construct a daemon thread to be part of a specified thread group.

Method Summary

Modifier and Type	Method	Description
Runnable	getRunnable()
final void	run()
final void	start()
void	work()	Override this instead of run()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Details

Daemon

public Daemon()

Construct a daemon thread.

Daemon

public Daemon(Runnable runnable)

Construct a daemon thread.

Parameters:

runnable - runnable.

Daemon

public Daemon(ThreadGroup group,
 Runnable runnable)

Construct a daemon thread to be part of a specified thread group.

Parameters:

group - thread group.

runnable - runnable.

Method Details

start

public final void start()

Overrides:

start in class Thread

work

public void work()

Override this instead of run()

run

public final void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

getRunnable

public Runnable getRunnable()