@SuppressWarnings("unchecked")
protected <T> Task<T> submitNewTask(final Map<?, ?> flags, final Task<T> task) {
if (task instanceof ScheduledTask)
return (Task<T>) submitNewScheduledTask(flags, (ScheduledTask) task);
tasksById.put(task.getId(), task);
totalTaskCount.incrementAndGet();
beforeSubmit(flags, task);
if (((TaskInternal<T>) task).getJob() == null)
throw new NullPointerException(
"Task " + task + " submitted with with null job: job must be supplied.");
Callable<T> job =
new Callable<T>() {
public T call() {
try {
T result = null;
Throwable error = null;
String oldThreadName = Thread.currentThread().getName();
try {
if (RENAME_THREADS) {
String newThreadName =
oldThreadName
+ "-"
+ task.getDisplayName()
+ "["
+ task.getId().substring(0, 8)
+ "]";
Thread.currentThread().setName(newThreadName);
}
beforeStart(flags, task);
if (!task.isCancelled()) {
result = ((TaskInternal<T>) task).getJob().call();
} else throw new CancellationException();
} catch (Throwable e) {
error = e;
} finally {
if (RENAME_THREADS) {
Thread.currentThread().setName(oldThreadName);
}
afterEnd(flags, task);
}
if (error != null) {
if (log.isDebugEnabled()) {
// debug only here, because we rethrow
log.debug(
"Exception running task " + task + " (rethrowing): " + error.getMessage(),
error);
if (log.isTraceEnabled())
log.trace(
"Trace for exception running task "
+ task
+ " (rethrowing): "
+ error.getMessage(),
error);
}
throw Exceptions.propagate(error);
}
return result;
} finally {
((TaskInternal<?>) task).runListeners();
}
}
};
// If there's a scheduler then use that; otherwise execute it directly
Set<TaskScheduler> schedulers = null;
for (Object tago : task.getTags()) {
TaskScheduler scheduler = getTaskSchedulerForTag(tago);
if (scheduler != null) {
if (schedulers == null) schedulers = new LinkedHashSet<TaskScheduler>(2);
schedulers.add(scheduler);
}
}
Future<T> future;
if (schedulers != null && !schedulers.isEmpty()) {
if (schedulers.size() > 1)
log.warn(
"multiple schedulers detected, using only the first, for " + task + ": " + schedulers);
future = schedulers.iterator().next().submit(job);
} else {
future = runner.submit(job);
}
// on completion, listeners get triggered above; here, below we ensure they get triggered on
// cancel
// (and we make sure the same ExecutionList is used in the future as in the task)
ListenableFuture<T> listenableFuture =
new ListenableForwardingFuture<T>(future, ((TaskInternal<T>) task).getListeners()) {
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
boolean result = false;
if (!task.isCancelled()) result |= task.cancel(mayInterruptIfRunning);
result |= super.cancel(mayInterruptIfRunning);
((TaskInternal<?>) task).runListeners();
return result;
}
};
((TaskInternal<T>) task).initResult(listenableFuture);
return task;
}
