48 lines
1.1 KiB
Java

package org.bukkit.craftbukkit.util;
import java.util.concurrent.ExecutionException;
public abstract class Waitable<T> implements Runnable {
private enum Status {
WAITING,
RUNNING,
FINISHED,
}
Throwable t = null;
T value = null;
Status status = Status.WAITING;
@Override
public final void run() {
synchronized (this) {
if (status != Status.WAITING) {
throw new IllegalStateException("Invalid state " + status);
}
status = Status.RUNNING;
}
try {
value = evaluate();
} catch (Throwable t) {
this.t = t;
} finally {
synchronized (this) {
status = Status.FINISHED;
this.notifyAll();
}
}
}
protected abstract T evaluate();
public synchronized T get() throws InterruptedException, ExecutionException {
while (status != Status.FINISHED) {
this.wait();
}
if (t != null) {
throw new ExecutionException(t);
}
return value;
}
}