org.yamcs.cfdp.Timer Maven / Gradle / Ivy
package org.yamcs.cfdp;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* Implements a timer used by CFDP for verifying the sending of EOF, FIN and NAK PDUs
*
*
* This class works with one thrad executor and expects all methods to be called on the executor thread.
* @author nm
*
*/
public class Timer {
final int maxNumAttempts;
final long timeout;
final ScheduledThreadPoolExecutor executor;
int numAttempts;
ScheduledFuture scheduledFuture;
public Timer(ScheduledThreadPoolExecutor executor, int maxNumAttempts, long timeout) {
this.maxNumAttempts = maxNumAttempts;
this.timeout = timeout;
this.executor = executor;
}
public void start(Runnable onIntermediate, Runnable onFinal) {
numAttempts = 0;
if (scheduledFuture != null) {
scheduledFuture.cancel(true);
}
scheduledFuture = executor.scheduleAtFixedRate(() -> {
if (maxNumAttempts < 0 || numAttempts < maxNumAttempts) {
onIntermediate.run();
} else {
scheduledFuture.cancel(true);
onFinal.run();
}
numAttempts++;
}, timeout, timeout, TimeUnit.MILLISECONDS);
}
public void cancel() {
if (scheduledFuture != null) {
scheduledFuture.cancel(true);
scheduledFuture = null;
}
}
boolean isActive() {
return scheduledFuture != null;
}
}