ADDITIONAL SYSTEM INFORMATION :
MacOS Catalina
openjdk 14.0.1 2020-04-14
OpenJDK Runtime Environment (build 14.0.1+14)
OpenJDK 64-Bit Server VM (build 14.0.1+14, mixed mode, sharing)


A DESCRIPTION OF THE PROBLEM :
Submissionpublisher allows to publish elements through the submit method. That method can block if there is no room in the publisher buffer, waiting for a consumer to claim some data.
Submission publisher offers the close() method. Such method should call the onCompleted() method of the subscriber

If a blocking publication attempt is in progress, a call to close() do not call the onComplete and hangs


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
See the attached code

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
- onComplete called according to documentation
- close should complete without hanging
ACTUAL -
- onComplete is not called
- close hangs
- submit stay blocked

---------- BEGIN SOURCE ----------
    public static void main(String[] args) throws InterruptedException {
        SubmissionPublisher<Integer> sp = new SubmissionPublisher<>(ForkJoinPool.commonPool(), 1);
        sp.subscribe(new Flow.Subscriber<>() {
            private Flow.Subscription sub;
            @Override
            public void onSubscribe(Flow.Subscription subscription) {
                this.sub = subscription;
            }

            @Override
            public void onNext(Integer item) {

            }

            @Override
            public void onError(Throwable throwable) {
                System.err.println("Err");
                this.sub.cancel();
            }

            @Override
            public void onComplete() {
                System.err.println("Completed");
                this.sub.cancel();
            }
        });
        CompletableFuture.runAsync(() -> { sp.submit(1); sp.submit(2); });
        TimeUnit.SECONDS.sleep(1);
        System.out.println("Going to hang...");
        sp.close();
        System.out.println("Not hanged!?");
    }
---------- END SOURCE ----------

FREQUENCY : always