SubmissionPublisher#closeExceptionally does trigger Subscriber#onError,
but based on javadoc, I cannot really be sure that it will be called,
since it contains exactly the same wording as SubmissionPublisher#close
/** * Unless already closed, issues {@link *
Flow.Subscriber#onError(Throwable) onError} signals to current *
subscribers with the given error, and disallows subsequent * attempts to
publish. Future subscribers also receive the given * error. Upon return,
this method does <em>NOT</em>guarantee * that all subscribers have yet
completed. * * @param error the {@code onError} argument sent to
subscribers * @throws NullPointerException if error is null */
So, Pavel, if that is not a bug, how can the SubmissionPublisher be
closed in a way that subscribers are notified?
Thanks for the link to the other mailing list - do I understand it
correctly that I should move this thread there?
Thanks and regards,
Pavel
On 21/02/2017 12:15, Pavel Rappo wrote:
I believe, the most appropriate place for concurrency-related questions is
http://altair.cs.oswego.edu/mailman/listinfo/concurrency-interest
As for the question itself. I don't think this behaviour is a bug.
SubmissionPublisher.close() seems to be a graceful way of shutting down (in
contrast with SubmissionPublisher.closeExceptionally()), akin to putting a EOF
on an input stream.
My reading of the javadoc is that after SubmissionPublisher.close has been
invoked, the publisher will no longer accept any attempts to publish items and
will call Subscriber.onClose() *eventually*.
On 21 Feb 2017, at 09:24, Pavel Bucek <pavel.bu...@oracle.com> wrote:
there is a formatting issue in the code snippet, publisher.close() should be on
the new line:
{
SubmissionPublisher<String> publisher =new SubmissionPublisher<>();
publisher.subscribe(new Flow.Subscriber<String>() {
@Override public void onSubscribe(Flow.Subscription subscription) { }
@Override public void onNext(String item) { }
@Override public void onError(Throwable throwable) {
System.out.println("onError()");
}
@Override public void onComplete() {
System.out.println("onComplete()");
}
});
publisher.submit("item");// if this is commented out, #onComplete is
invoked.
publisher.close();
}
On 21/02/2017 10:16, Pavel Bucek wrote:
Hi all,
firstly - please let me know if this is is a wrong place to send this; I wasn't
able to find list specific to concurrency.
Consider following example:
{
SubmissionPublisher<String> publisher =new SubmissionPublisher<>();
publisher.subscribe(new Flow.Subscriber<String>() {
@Override public void onSubscribe(Flow.Subscription subscription) { }
@Override public void onNext(String item) { }
@Override public void onError(Throwable throwable) {
System.out.println("onError()");
}
@Override public void onComplete() {
System.out.println("onComplete()");
}
});
publisher.submit("item");// if this is commented out, #onComplete is
invoked. publisher.close();
}
I'd expect that Subscriber#onComplete is invoked after calling publisher.close(), but it
is not happening. Curiously, when I comment out 'publisher.submit("item")',
Subscriber#onComplete is indeed invoked.
SubmissionPublisher#close() javadoc says:
/** * Unless already closed, issues {@link * Flow.Subscriber#onComplete() onComplete}
signals to current * subscribers, and disallows subsequent attempts to publish. * Upon
return, this method does <em>NOT</em>guarantee that all * subscribers have yet
completed. */
So it seems like it will be invoked in different thread or something like that,
but it is not invoked ever (or more precisely - not during 10 second after the
publisher is closed. There is nothing else running on that particular jvm
instance).
Also, publisher#isClosed() returns true and publisher#getNumberOfSubscribers()
returns 0.
I'm using Java(TM) SE Runtime Environment (build
9-ea+157-jigsaw-nightly-h6115-20170219)
What am I doing wrong?
Thanks and regards, Pavel
