filebot/source/net/sourceforge/tuned/Timer.java

95 lines
2.0 KiB
Java

package net.sourceforge.tuned;
import java.util.concurrent.RunnableScheduledFuture;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
public abstract class Timer implements Runnable {
private final ScheduledThreadPoolExecutor executor;
private RunnableScheduledFuture<?> scheduledFuture;
private Thread shutdownHook;
public Timer() {
executor = new ScheduledThreadPoolExecutor(1);
executor.setKeepAliveTime(200, TimeUnit.MILLISECONDS);
executor.allowCoreThreadTimeOut(true);
}
public synchronized void set(long delay, TimeUnit unit, boolean runBeforeShutdown) {
removeScheduledFuture();
Runnable r = this;
if (runBeforeShutdown) {
addShutdownHook();
// remove shutdown hook after execution
r = new Runnable() {
@Override
public void run() {
try {
Timer.this.run();
} finally {
removeShutdownHook();
}
}
};
} else {
// remove existing shutdown hook, if any
removeShutdownHook();
}
scheduledFuture = (RunnableScheduledFuture<?>) executor.schedule(r, delay, unit);
}
public synchronized void cancel() {
removeScheduledFuture();
removeShutdownHook();
}
private synchronized void removeScheduledFuture() {
if (scheduledFuture != null) {
try {
scheduledFuture.cancel(false);
executor.remove(scheduledFuture);
} finally {
scheduledFuture = null;
}
}
}
private synchronized void addShutdownHook() {
if (shutdownHook == null) {
shutdownHook = new Thread(this);
Runtime.getRuntime().addShutdownHook(shutdownHook);
}
}
private synchronized void removeShutdownHook() {
if (shutdownHook != null) {
try {
if (shutdownHook != Thread.currentThread()) {
// can't remove shutdown hooks anymore, once runtime is shutting down,
// so don't remove the shutdown hook, if we are running on the shutdown hook
Runtime.getRuntime().removeShutdownHook(shutdownHook);
}
} finally {
shutdownHook = null;
}
}
}
}