/* * Timer - simple Thread based Timer support * * Copyright (c) 1998 *    Transvirtual Technologies, Inc.  All rights reserved. * * See the file "license.terms" for information on usage and redistribution  * of this file.  * * @author P.Mehlitz */package kaffe.util;public class Timer  extends Thread{	private TimerClientEntry[] clients;	private int nClients;	private int resolution;	private boolean stop;	private static Timer defaultTimer;public Timer () {	resolution = Integer.MAX_VALUE;		clients = new TimerClientEntry[5];	for ( int i=0; i<clients.length; i++ ) {		clients[i] = new TimerClientEntry();	}		setDaemon( true);	start();}public synchronized boolean addClient ( TimerClient tc, int startWait, int interval ) {	TimerClientEntry tce;	int i;	// we allow just a single instance of a client	// (otherwise we would need client ids to distinguish	// notifications and removes)	for ( i=0; i<nClients; i++ ){		if ( clients[i].client == tc )			return false;	}	if ( nClients == clients.length ){		TimerClientEntry[] newClients = new TimerClientEntry[clients.length+10];		System.arraycopy( clients, 0, newClients, 0, nClients);		clients = newClients;		for ( i=nClients; i<clients.length; i++ )			clients[i] = new TimerClientEntry();	}	tce = clients[nClients++];	tce.client = tc;	tce.nextNotify = System.currentTimeMillis() + startWait;	tce.interval = interval;	// If interval is smaller than current resolution, drop current	// resolution and wake the timer thread.	if (interval < resolution) {		resolution = interval;		interrupt();	}	if ( nClients == 1 ) {		notify();	}		return true;}public static synchronized Timer getDefaultTimer () {	if ( defaultTimer == null ) {		defaultTimer = new Timer();	}		return defaultTimer;}public synchronized boolean removeClient ( TimerClient tc ) {	int newres;	for (int i=0; i < nClients; i++ ) {		TimerClientEntry tce = clients[i];		if ( tce.client == tc ) {			int i1 = i+1;			int nmax = nClients-1;			tce.client = null;  // don't leak						if (i1 < nmax)				System.arraycopy( clients, i1, clients, i, (nmax-i));			clients[--nClients] = tce;						// adapt the timer resolution to the lowest remaining interval			if ( (resolution == tce.interval) && (nClients > 0) ) {				for ( i=0, newres=Integer.MAX_VALUE; i<nClients; i++ ){					if ( clients[i].interval < newres )						newres = clients[i].interval;				}				// No need to interrupt, this just increases the interval				// and takes effect after the next tick automatically.				// in case it was the last entry, we go to wait, anyway				// (but NOT here, we might be in a different thread)				if ( newres != resolution )					resolution = newres;			}			return true;		}	}		return false;}public void run () {	long t;	int  i;	while ( !stop ) {		try {			while ( !stop ) {				synchronized ( this ) {					if ( nClients == 0 ){						wait();					}					t = System.currentTimeMillis();					for ( i=0; i<nClients; i++ ) {						TimerClientEntry tce = clients[i];						if ( t > tce.nextNotify ) {							tce.client.timerExpired( this);							tce.nextNotify = t + tce.interval;						}					}				}				if ( nClients > 0 ){ // otherwise we go waiting, anyway					Thread.sleep(resolution);				}			}		}		catch ( InterruptedException _ ) {			// deliberately tolerated		}		catch ( Exception x ) {			x.printStackTrace();		}	}}public void startNotify () {	stop = false;	start();}public void stopNotify () {	stop = true;}}class TimerClientEntry{	TimerClient client;	long nextNotify;	int interval;}