81 lines
2.0 KiB
Java

package de.teamteamteam.spacescooter.thread;
/**
* Since things like drawing the next image or triggering the next game tick
* need to happen in time, this TimedThread allows more precise timing
* combined with a nap for the cpu in case there is enough time for it.
*/
public abstract class TimedThread extends Thread {
/**
* Internal interval in which to trigger work().
* Calculated based on setHz()
*/
private long workInterval;
/**
* Internal value representing runtime of the last work() call.
*/
private long workTime;
/**
* This method sets the actual working interval based on hz.
*
* @param hz
*/
public final void setHz(int hz) {
this.workInterval = (1000L * 1000L * 1000L) / (long) hz;
}
/**
* This method takes care of the timing.
*/
public final void run() {
while (true) {
long workStart = System.nanoTime();
// do the actual work
this.work();
long workDone = System.nanoTime();
//calculate time of work
this.workTime = (workDone - workStart);
long timeToWait = this.workInterval - workTime;
long msToWait = timeToWait / 1000000;
// wait using sleep for bigger intervals
if (msToWait > 1) {
try {
//make sure there is a little buffer for manual waiting loop left
Thread.sleep(Math.max(0,(msToWait - 1)));
} catch (InterruptedException e) {
System.err.println("[" + this.getName() + "]" + e.getStackTrace());
}
}
//wait manually for the rest of the interval
long sleepUntil = workStart + this.workInterval;
long currentTime = System.nanoTime();
while ((sleepUntil - currentTime) > 10) {
if((sleepUntil - currentTime) > 10000) {
Thread.yield(); //Give other threads a chance.
}
currentTime = System.nanoTime();
}
}
}
/**
* Do the actual thread work in here.
*/
public abstract void work();
/**
* Returns current value of workTime.
* Tells how many nanoseconds the last work() call needed to complete.
*/
public long getWorkTime() {
return this.workTime;
}
}