reactor/reactor-core v3.0.4.RELEASE on GitHub

This is the 4th release of Reactor 3.0, part of {ALUMINIUM-RELEASE} Release Train.

This is a recommended update for all Reactor 3 users.

⚠️ Update considerations and deprecations

Cancellation is being deprecated and will be removed in 3.1.0. The new Disposable replaces it (#322)
- Scheduler now implements Disposable. We advise that if you have an implementation of Scheduler, you explicitly implement both shutdown() and dispose(), with the concrete code in dispose() and the shutdown() method calling dispose().
- Same with Scheduler.Worker
A report has been issued in #339 and might force library developers to issue a patch release recompiled against reactor-core 3.0.4 if they wish to offer third party users option to upgrade too.

A new BaseSubscriber has been added to allow to easily subscribe and play
with the request/cancel. It offers hooks, including a hookFinally that always
execute on sequence termination (#254, #279)
Added new buffer operators based on predicates: bufferUntil and bufferWhile (#227)
The new doFinally operator allows to perform a side effect on any type of
termination (onError, onComplete and cancel) (#251)
When using a WorkQueueProcessor, a best effort attempt at detecting the capacity
of the underlying Executor is made in order to prevent you from subscribing
too much (#199)
Added a doOnEach variant to Flux that takes a Consumer<Signal> (#264, #289)
Added a onBackpressureBuffer variant that takes a BufferOverflowStrategy,
allowing to decide what to do if the bounded buffer fills up: error, drop last
element, drop oldest element in buffer... (#281)
A variant of Mono.and based on a Function<T, Mono<V>> now allows to easily
combine a value and the result of applying an asynchronous processing on it
into a Tuple2 (#300)
Worker now has a isShutdown() method (#313)
A Disposable interface has been introduced, preparing to replace Cancellation. For now it extends Cancellation (#322)

FluxHandle sink always use onOperatorError (#282)
Rework handling of RejectedExecutionException in most processors (#275, #293, #298, #274, #299, #313, #319)
- the exception is more consistently thrown by all schedulers in case its underlying executor rejects a task because the scheduler was shut down.
Fix the onNext/onComplete callback reversal in async-fused sequences (#230)
A Callable returning null now always trigger onError(NPE) (#261)
Don't silence errorNotImplemented in Schedulers (#257)
Improve doOn callback failures handling (#247)
Prevent logging of a Subscription as a Collection in log() (instead using
a dedicated format), which would cause a NotImplementedException with some
loggers applying custom logic to Collections (#262)
Fix flatMapSequential dropping some elements when there are more than
prefetch source elements (workaround: use same number for prefetch and
maxConcurrency) (#301)
Fix the sharing of state between multiple subscribers for Mono#doOnTerminate (#242)