I wrapped a ThreadPoolExecutor in an implementation of ExecutorService of my own, just to send it any filesystem writing task, so they would be treated sequencially and one-by-one. (No need to harass this poor disk writing head.)
The wrapper comes in handy by:
- allowing me to Inject this ThreadPool as a Guice Singleton pretty much everywhere I need it
- telling me in real-time how much more work there is left to do
This last feature is acomplished by the call to logUtils.writingHeartbeat(int) which logs a message about how many jobs are still in the queue if a "sufficient" time has been elapsed since last logging. It works pretty well in regards of writing logs at the desired intervals, but always tells me there is 0 files remaining to write. Which sounds fishy given the execution times.
What am I doing wrong?
@Singleton
public class WritersThreadPool implements ExecutorService {
private final ThreadPoolExecutor innerPool;
private final LogUtils logUtils;
@Inject
public WritersThreadPool(LogUtils logUtils) {
innerPool = new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
this.logUtils = logUtils;
}
@Override
public Future<?> submit(final Runnable r) {
return innerPool.submit(new Callable<Void>() {
@Override
public Void call() throws Exception {
r.run();
logUtils.writingHeartbeat(innerPool.getQueue().size());
return null;
}
});
}
(...) // Other implemented methods with no special behavior.
}
