private boolean isGroupChanged(final Group group, final Callback callback) {
final List<Resource> resources = group.getResources();
final AtomicBoolean isChanged = new AtomicBoolean(false);
final List<Future<?>> futures = new ArrayList<Future<?>>();
final boolean isAsync = context.getConfig().isResourceWatcherAsync();
try {
for (final Resource resource : resources) {
if (isAsync) {
futures.add(
executorServiceRef
.get()
.submit(
ContextPropagatingCallable.decorate(
new Callable<Void>() {
public Void call() throws Exception {
checkResourceChange(resource, group, callback, isChanged);
return null;
}
})));
} else {
checkResourceChange(resource, group, callback, isChanged);
}
}
if (isAsync) {
LOG.debug("await async execution");
// await for all futures to complete before returning the result
for (final Future<?> future : futures) {
future.get();
}
}
} catch (final Exception e) {
LOG.debug("Exception while onResourceChange is invoked", e);
}
LOG.debug("group={}, changed={}", group.getName(), isChanged);
return isChanged.get();
}
/**
* @VisibleForTesting
*
* @param callable {@link Callable} to submit for asynchronous execution.
*/
void submit(final Callable<Void> callable) {
executorServiceRef.get().submit(callable);
}