www.pudn.com > ejip.zip > RtThread.java

/** 
*	RtThread.java on PC for simulation of JOP 
*/ 
 
package javax.joprt; 
 
import com.jopdesign.sys.Native; 
 
public class RtThread extends Thread { 
 
	private boolean nextOk; 
	private int period;			// period in cycles 
private int next; 
 
	private static boolean start; 
 
	private RtThread() {}; 
 
	public RtThread(int ms) { 
		// period = ms*Thread.MS; 
period = ms*20000; 
		nextOk = false; 
	} 
 
	public static void startMission() { 
		start = true; 
	} 
 
	public void waitForMission() { 
 
		while (!start) { 
			yield(); 
		} 
		nextOk = true; 
		next = Native.rd(Native.IO_CNT); 
	} 
 
 
	public boolean waitForNextPeriod() { 
 
		if (!nextOk) { 
			next = Native.rd(Native.IO_CNT);		// this should not happen! 
			nextOk = true;							// you forgot to wait on start mission 
		} 
 
		next += period; 
 
		int i = Native.rd(Native.IO_CNT); 
		if (next-i < 0) {							// missed time! 
			next = i;								// correct next 
			return false; 
		} 
/* 
		state = WAITING; 
		yield(); 
*/ 
		while (next-Native.rd(Native.IO_CNT) >= 0) {	// 'busy' wait with yield. 
try { Thread.sleep(1); } catch (Exception e) {} 
			yield(); 
		} 
		return true; 
	} 
 
}