/** Processes (at least) the first event in the queue. */
void serviceEvent() {
checkState();
ClientSessionServiceImpl sessionService = ClientSessionServiceImpl.getInstance();
ManagedQueue<SessionEvent> eventQueue = getQueue();
DataService dataService = ClientSessionServiceImpl.getDataService();
for (int i = 0; i < sessionService.eventsPerTxn; i++) {
SessionEvent event = eventQueue.poll();
if (event == null) {
// no more events
break;
}
logger.log(Level.FINEST, "processing event:{0}", event);
int cost = event.getCost();
if (cost > 0) {
dataService.markForUpdate(this);
writeBufferAvailable += cost;
if (logger.isLoggable(Level.FINEST)) {
logger.log(
Level.FINEST,
"{0} cleared reservation of " + "{1,number,#} bytes, leaving {2,number,#}",
this,
cost,
writeBufferAvailable);
}
}
event.serviceEvent(this);
}
}
/**
* Attempts to enqueue the specified {@code event}, and returns {@code true} if successful, and
* {@code false} otherwise.
*
* @param event the event
* @return {@code true} if successful, and {@code false} otherwise
* @throws MessageRejectedException if the cost of the event exceeds the available buffer space
* in the queue
*/
boolean offer(SessionEvent event) {
int cost = event.getCost();
if (cost > writeBufferAvailable) {
ClientSessionServiceImpl sessionService = ClientSessionServiceImpl.getInstance();
if (sessionService.receiveMessageRejectedOp != null) {
sessionService.receiveMessageRejectedOp.report();
}
throw new MessageRejectedException(
"Not enough queue space: "
+ writeBufferAvailable
+ " bytes available, "
+ cost
+ " requested");
}
boolean success = getQueue().offer(event);
if (success && cost > 0) {
ClientSessionServiceImpl.getDataService().markForUpdate(this);
writeBufferAvailable -= cost;
if (logger.isLoggable(Level.FINEST)) {
logger.log(
Level.FINEST,
"{0} reserved {1,number,#} leaving {2,number,#}",
this,
cost,
writeBufferAvailable);
}
}
return success;
}