Package fr.dyade.aaa.common

Class Daemon

java.lang.Object

fr.dyade.aaa.common.Daemon

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

AdminProxy.AdminMonitor, AmqpAcquisition.ConnectionUpdater, AMQPConnectionListener, AMQPConnectionListener.NetServerOut, DistributionDaemon, HttpNetwork.NetServerIn, HttpNetwork.NetServerOut, IOControl.Reader, JMSAcquisition.ConnectionUpdater, JMSModule.ReconnectionDaemon, JMSModule.StartupDaemon, LiveServerConnection.ReconnectionDaemon, MultiSessionConsumer.MessageDispatcher, MultiSessionConsumer.MessageDispatcher, NGNetwork.Dispatcher, NGNetwork.NetServer, PoolNetwork.Dispatcher, PoolNetwork.Sender, PoolNetwork.WakeOnConnection, PoolNetwork.WatchDog, Proxy.NetServerIn, ReliableTcpConnection.Reader, ReliableTcpConnection.Reader, RequestMultiplexer.DemultiplexerDaemon, RequestMultiplexer.DemultiplexerDaemon, RestAcquisitionAsync.XDaemon, Session.SessionDaemon, Session.SessionDaemon, SimpleNetwork.NetServerIn, SimpleNetwork.NetServerOut, TcpConnectionListener, TcpReader, TcpServer.Monitor, TcpWriter, UDPNetwork.MessageBuilder, UDPNetwork.NetServerIn, UDPNetwork.NetServerOut, UDPNetwork.WatchDog

public abstract class Daemon
extends Object
implements Runnable

The Daemon class represents a basic active component in a server. It provides useful code to start and safely stop inner Thread.

Main loop of daemon:

  try {
    while (running) {
        canStop = true;

        // Get a notification, then execute the right reaction.
        try {
          // Get a request
          ...
        } catch (InterruptedException exc) {
          continue;
        }
        
        canStop = false;

        // executes the request
        ...
    }
  } finally {
    finish();
  }
 

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	canStop	Boolean variable used to stop the daemon properly.
private boolean	daemon	The daemon's nature.
protected ThreadGroup	group	The group of this thread.
protected Logger	logmon
private String	name	The daemon's name.
protected int	priority	The priority that is assigned to the daemon.
protected boolean	running	Boolean variable used to stop the daemon properly.
protected Thread	thread	The active component of this daemon.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Daemon(String name)	Deprecated.
protected	Daemon(String name, Logger logmon)	Allocates a new Daemon object.

Method Summary

Modifier and Type	Method	Description
protected abstract void	close()	Releases any resources attached to this daemon.
protected void	finish()
String	getName()	Returns this daemon's name.
void	interrupt()	Interrupts this daemon.
boolean	isCurrentThread()	Tests if the daemon's thread is the current one.
boolean	isRunning()	Tests if this daemon is alive.
void	setDaemon(boolean daemon)	Marks the daemon's thread as either a daemon thread a user thread.
void	setName(String name)	Set the name of the daemon's thread.
void	setPriority(int newPriority)	Changes the priority of this daemon.
void	setThreadGroup(ThreadGroup group)	Set the thread group to which this daemon's thread belongs.
protected abstract void	shutdown()	Interrupts a thread that waits for long periods.
void	start()	Causes this daemon to begin execution.
void	stop()	Forces the daemon to stop executing.
String	toString()	Returns a string representation of this daemon.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Runnable

run

Field Detail

logmon

protected Logger logmon

running

protected volatile boolean running

Boolean variable used to stop the daemon properly. The daemon tests this variable between each request, and stops if it is false.

See Also:

start(), stop()

canStop

protected volatile boolean canStop

Boolean variable used to stop the daemon properly. If this variable is true then the daemon is waiting for a long time and it can be interrupted, else it handles a request and it will exit after (it tests the running variable between each reaction)

thread

protected Thread thread

The active component of this daemon.

name

private String name

The daemon's name.

daemon

private boolean daemon

The daemon's nature.

priority

protected int priority

The priority that is assigned to the daemon.

group

protected ThreadGroup group

The group of this thread. Note: The ThreadGroup is just used as information.

Constructor Detail

Daemon

protected Daemon(String name)

Deprecated.

Allocates a new Daemon object. Be careful, the use of this constructor is not recommended as it does not dissociate the corresponding logger.

Parameters:

name - the name of the new Daemon

Daemon

protected Daemon(String name,
                 Logger logmon)

Allocates a new Daemon object.

Parameters:

name - the name of the new Daemon

logmon - inherited logging monitor

Method Detail

isRunning

public boolean isRunning()

Tests if this daemon is alive.

Returns:

true if this daemon is alive; false otherwise.

getName

public final String getName()

Returns this daemon's name.

Returns:

this daemon's name.

toString

public String toString()

Returns a string representation of this daemon.

Overrides:

toString in class Object

Returns:

A string representation of this daemon.

setDaemon

public void setDaemon(boolean daemon)

Marks the daemon's thread as either a daemon thread a user thread. This method must be called before the daemon is started.

Parameters:

daemon - if true marks the daemon's thread as either a daemon thread.

Throws:

IllegalThreadStateException - if this daemon was already active.

setPriority

public void setPriority(int newPriority)

Changes the priority of this daemon. If the daemon is running calls the setPriority method on corresponding thread, else stores value for next start.

Parameters:

newPriority - the new priority.

setThreadGroup

public void setThreadGroup(ThreadGroup group)

Set the thread group to which this daemon's thread belongs. This method must be called before the daemon is started.

Parameters:

group - the thread group.

Throws:

IllegalThreadStateException - if this daemon was already active.

start

public void start()

Causes this daemon to begin execution. A new thread is created to execute the run method.

Throws:

IllegalThreadStateException - If the daemon was already started.

close

protected abstract void close()

Releases any resources attached to this daemon. Be careful, its method should be called more than one time.

shutdown

protected abstract void shutdown()

Interrupts a thread that waits for long periods. In some cases, we must use application specific tricks. For example, if a thread is waiting on a known socket, we have to close the socket to cause the thread to return immediately. Unfortunately, there really isn't any technique that works in general.

interrupt

public void interrupt()

Interrupts this daemon.

finish

protected final void finish()

stop

public void stop()

Forces the daemon to stop executing. This method notifies thread that it should stop running, if the thread is waiting it is first interrupted then the shutdown method is called to close all resources.

isCurrentThread

public boolean isCurrentThread()

Tests if the daemon's thread is the current one.

Returns:

true if the daemon's thread is the current one, false otherwise.

setName

public void setName(String name)

Set the name of the daemon's thread.

Parameters:

name - the thread name.