AbstractUaaTokenProvider violates Publisher Spec. Rule 1.3

Hi,

I have observed below error related to Publisher Spec. Rule 1.3, while trying to get token in AbstractUaaTokenProvider.token(…) method -

reactor.core.Exceptions$ErrorCallbackNotImplemented: reactor.core.publisher.Sinks$EmissionException: Spec. Rule 1.3 - onSubscribe, onNext, onError and onComplete signaled to a Subscriber MUST be signaled serially.

Stack trace -
reactor.core.Exceptions$ErrorCallbackNotImplemented: reactor.core.publisher.Sinks$EmissionException: Spec. Rule 1.3 - onSubscribe, onNext, onError and onComplete signaled to a Subscriber MUST be signaled serially.
Caused by: reactor.core.publisher.Sinks$EmissionException: Spec. Rule 1.3 - onSubscribe, onNext, onError and onComplete signaled to a Subscriber MUST be signaled serially.
at reactor.core.publisher.InternalManySink.emitNext(InternalManySink.java:56)
Suppressed: The stacktrace has been enhanced by Reactor, refer to additional information below:
Assembly trace from producer [reactor.core.publisher.MonoCacheTime] :
reactor.core.publisher.Mono.checkpoint(Mono.java:2206)
org.cloudfoundry.reactor.tokenprovider.AbstractUaaTokenProvider.token(AbstractUaaTokenProvider.java:261)
Error has been observed at the following site(s):
*__checkpoint() ⇢ at org.cloudfoundry.reactor.tokenprovider.AbstractUaaTokenProvider.token(AbstractUaaTokenProvider.java:261)

While checking the flow with this stacktrace, it seems this error is getting thrown at InternalManySink.emitNext(...) level. It is failing due to state 'FAIL_NON_SERIALIZED', as tryEmitNext(..) is getting triggered by different threads at the same time.

It will be helpful if someone can share some insights on the same, and share any document for more idea on tokenprovider feature of cf java client or share any already existing issue on the same line for more details

Thanks.

Commencez dans AbstractUaaTokenProvider.token(...) à AbstractUaaTokenProvider.java:261 et examinez le flux environnant du fournisseur de tokens ainsi que l’utilisation des sinks de Reactor. Reproduisez des appels concurrents à tryEmitNext qui entraînent FAIL_NON_SERIALIZED, puis vérifiez que les abonnés aux tokens reçoivent les signaux de manière séquentielle et que l’erreur signalée ne se produit plus.