@Override
public void run() {
try {
boolean running = true;
while (running) {
try {
// block on event availability
ThreadBoundEvent event = queue.take();
// add to the batch, and see if we can add more
batch.add(event);
if (maxBatchSize > 0) {
queue.drainTo(batch, maxBatchSize);
}
// check for the stop condition (and remove it)
// treat batches of 1 (the most common case) specially
if (batch.size() > 1) {
ListIterator<ThreadBoundEvent> itr = batch.listIterator();
while (itr.hasNext()) {
ThreadBoundEvent next = itr.next();
if (next.getClass().equals(ShutdownTask.class)) {
running = false;
((ShutdownTask) next).latch.countDown();
itr.remove();
}
}
eventProcessor.process(batch);
} else {
// just the one event, no need to iterate
if (event.getClass().equals(ShutdownTask.class)) {
running = false;
((ShutdownTask) event).latch.countDown();
} else {
eventProcessor.process(batch);
}
}
} catch (InterruptedException e) {
LOG.warn(
String.format(
"Consumer on queue %s interrupted.", Thread.currentThread().getName()));
// ignore
} catch (Throwable exception) {
LOG.error(
String.format(
"exception on queue %s while executing events",
Thread.currentThread().getName()),
exception);
} finally {
// reset the batch
batch.clear();
}
}
} catch (Throwable unexpectedThrowable) {
// we observed some cases where trying to log the inner exception threw an error
// don't use the logger here as that seems to be causing the problem in the first place
System.err.println("Caught and unexpected Throwable while logging");
System.err.println(
"This problem happens when jar files change at runtime, JVM might be UNSTABLE");
unexpectedThrowable.printStackTrace(System.err);
}
}
/**
* Schedule a runnable for execution.
*
* @param event The runnable to execute
*/
public void execute(ThreadBoundEvent event) {
if (shuttingDown.get()) {
throw new RejectedExecutionException("The system is shutting down.");
}
int bucket = getBucket(event.getKey());
BlockingQueue<ThreadBoundEvent> queue = queues.get(bucket);
queue.add(event);
}