package org.infinispan.atomic.container;
import java.util.ArrayDeque;
import java.util.Queue;
import java.util.concurrent.Executor;
/**
*
* This executor below serializes the submission of tasks to a second executor, illustrating a composite executor.
* From the Java Executor class documentation.
*
* @author Pierre Sutra
* @since 7.2
*/
public class SerialExecutor implements Executor {
final Queue<Runnable> tasks = new ArrayDeque<Runnable>();
final Executor executor;
Runnable active;
public SerialExecutor(Executor executor) {
this.executor = executor;
}
public synchronized void execute(final Runnable r) {
tasks.offer(new Runnable() {
public void run() {
try {
r.run();
} finally {
scheduleNext();
}
}
});
if (active == null) {
scheduleNext();
}
}
protected synchronized void scheduleNext() {
if ((active = tasks.poll()) != null) {
executor.execute(active);
}
}
}