Prior to this commit, gh-31609 added the current observation context as
a request attribute for `WebClient` calls. While it was not confirmed as
the main cause, this feature was linked to several reports of memory
leaks. This would indeed attach more memory to the request object graph
at runtime - although it shouldn't prevent its collection by the GC.
This commit removes this feature and instead developers should get the
current observation from the reactor context if they wish to interact
with it.
Closes gh-32198
Prior to this commit, error signals flowing from the client response
publisher in `WebClient` would be set on the `Observation.Context`. This
is enough for the observation convention to collect data about the error
but observation handlers are not notified of this error.
This commit sets the error instead on the observation directly to fix
this issue.
Fixes gh-32389
webmvc.fn now also uses the StandardServletAsyncWebRequest wrapped response
to enforce lifecycle rules from Servlet spec (section 2.3.3.4).
See gh-32340
KClass instantiation in CoroutinesUtils is suboptimal, and should be
replaced by KTypes#isSubtypeOf checks using pre-instantiated types for
Flow, Mono and Publisher.
This commit impact on performances is significant since a throughput
increase between 2x and 3x has been measured on basic endpoints.
Closes gh-32390
This commit fixes an issue where a Cacheable method which returns a
Flux (or multi-value publisher) will be invoked once, but the returned
publisher is actually subscribed twice.
The previous fix 988f3630c would cause the cached elements to depend on
the first usage pattern / request pattern, which is likely to be too
confusing to users. This fix reintroduces the notion of exhausting the
original Flux by having a second subscriber dedicated to that, but uses
`refCount(2)` to ensure that the original `Flux` returned by the cached
method is still only subscribed once.
Closes gh-32370
Also fix a couple of related issues:
- add AsyncRequestNotUsableException to the list of exceptions
that imply response issues.
- handle exceptions from @ExceptionHandler regardless of whether
thrown immediately or via Publisher.
Closes gh-32359
This commit fixes an issue where a Cacheable method which returns a
Flux (or multi-value publisher) will be invoked once, but the returned
publisher is actually subscribed twice.
By using the Reactor `tap` operator, we ensure that we can emit values
downstream AND accumulate emitted values into the List with a single
subscription.
The SignalListener additionally handles scenarios involving cancel,
for instance in case of a `take(1)` in the chain. In that case values
emitted up until that point will have been stored into the List buffer,
so we can still put it in the cache. In case of error, no caching occurs
and the internal buffer is cleared. This implementation also protects
against competing onComplete/onError signals and cancel signals.
Closes gh-32370
The following adjustments are also made as a result:
- Use int to check if lock is held and unlock is needed, given that
for non-async requests we don't need to obtain a lock.
- Protect access methods getOutputStream and getWriter with the
same locking and state checks.
Closes gh-32340
ServletResponseHttpHeaders#get should be annotated with `@Nullable` and
return null instead of a singleton list containing null when there is no
content type header.
Closes gh-32362
In addition to using the ServletOutputStream, it's also possible to call
ServletResponse#flushBuffer, so the ServletOutputStream wrapper logic needs
to apply there as well.
See gh-32340
The wrapped response prevents use after AsyncListener onError or completion
to ensure compliance with Servlet Spec 2.3.3.4.
The wrapped response is applied in RequestMappingHandlerAdapter.
The wrapped response raises AsyncRequestNotUsableException that is now
handled in DefaultHandlerExceptionResolver.
See gh-32340
Prior to this commit, if a Spring Expression Language (SpEL) expression
referenced the root context object via the #root or #this variable, we
inserted a checkcast in the generated byte code that cast the object to
its concrete type. However if the root context object's type was
non-public, that resulted in an IllegalAccessError when the compiled
byte code was executed.
VariableReference.getValueInternal() already contains a solution for
global variables which inserts a checkcast to Object in the generated
byte code instead of to the object's concrete non-public type.
This commit therefore applies the same logic to #root (or #this when
used to reference the root context object) that is already applied to
global variables.
Closes gh-32356
