public void run() {
HashMap<Queue, LinkedList<MessageReference>> refs =
new HashMap<Queue, LinkedList<MessageReference>>();
runnables.remove(deliveryTime);
final long now = System.currentTimeMillis();
if (now < deliveryTime) {
// Ohhhh... blame it on the OS
// on some OSes (so far Windows only) the precision of the scheduled executor could
// eventually give
// an executor call earlier than it was supposed...
// for that reason we will schedule it again so no messages are lost!
// we can't just assume deliveryTime here as we could deliver earlier than what we are
// supposed to
// this is basically a hack to work around an OS or JDK bug!
if (trace) {
ActiveMQServerLogger.LOGGER.trace(
"Scheduler is working around OS imprecisions on "
+ "timing and re-scheduling an executor. now="
+ now
+ " and deliveryTime="
+ deliveryTime);
}
ScheduledDeliveryHandlerImpl.this.scheduleDelivery(deliveryTime);
}
if (ScheduledDeliveryHandlerImpl.trace) {
ActiveMQServerLogger.LOGGER.trace(
"Is it "
+ System.currentTimeMillis()
+ " now and we are running deliveryTime = "
+ deliveryTime);
}
synchronized (scheduledReferences) {
Iterator<RefScheduled> iter = scheduledReferences.iterator();
while (iter.hasNext()) {
MessageReference reference = iter.next().getRef();
if (reference.getScheduledDeliveryTime() > now) {
// We will delivery as long as there are messages to be delivered
break;
}
iter.remove();
reference.setScheduledDeliveryTime(0);
LinkedList<MessageReference> references = refs.get(reference.getQueue());
if (references == null) {
references = new LinkedList<MessageReference>();
refs.put(reference.getQueue(), references);
}
if (ScheduledDeliveryHandlerImpl.trace) {
ActiveMQServerLogger.LOGGER.trace(
"sending message " + reference + " to delivery, deliveryTime = " + deliveryTime);
}
references.addFirst(reference);
}
if (ScheduledDeliveryHandlerImpl.trace) {
ActiveMQServerLogger.LOGGER.trace("Finished loop on deliveryTime = " + deliveryTime);
}
}
for (Map.Entry<Queue, LinkedList<MessageReference>> entry : refs.entrySet()) {
Queue queue = entry.getKey();
LinkedList<MessageReference> list = entry.getValue();
if (trace) {
ActiveMQServerLogger.LOGGER.trace(
"Delivering " + list.size() + " elements on list to queue " + queue);
}
queue.addHead(list);
}
// Just to speed up GC
refs.clear();
}
