Prior to this commit, the `ConcurrentReferenceHashMap#Segment` would
recalculate its element count during the restructure phase by
subtracting the number of polled elements from the queue to the current
count.
Later, the newly restructured `references` array would only contain
references that 1) are not in the set of elements to purge and
2) that hold a non-null value.
The issues with this approach are multiple. The newly calculated count
is only an estimate, as some situations can make it invalid, even
temporarily.
* since we initially collected all elements to be purged from the queue,
the GC might have collected new values. This means that we might
filter out more references that we initially intended to
* because the restructure operation re-creates new references for all
elements in the original array, we might later get references from the
queue that are not in the array anymore. This could lead to
"duplicate" removals for the same value
Because several methods in the Segment class have special no-op behavior
when `count == 0`, an invalid count can lead to keys appearing missing
when they are actually still present. In some scenarios, this can
decrease the performance of the cache since values need to be
recalculated.
This commit fixes this inconsistency count issue by first using an
estimate in order to decide whether the array needs a resize and then by
counting the actual numbers of elements inserted in the restructured
array as the new count.
Fixes gh-31373
This commit adds a warning in the reference guide to address the
use cases where users might be tempted to use several property
placeholder configurers.
Closes gh-14623
Prior to this commit, HTTP server observations for Spring WebFlux could
be recorded twice for a single request in some cases. The "COMPLETE" and
"CANCEL" signals would race in the reactive pipeline and would trigger
both the `doOnComplete()` and ` `doOnCancel()` operators, each calling
`observation.stop()` on the current observation.
This would in fact publish two different observations for the same
request.
This commit ensures that the instrumentation uses the `Mono#tap`
operator to guard against this case and only call `Observation#stop`
once for each request.
Fixes gh-31417
Prior to this commit, a cancelled exchange would always result in an
`"status":"UNKNOWN"` KeyValue. This only applied to reactive variants,
as cancelled exchanges are not currently detected for Servlet
implementations.
In some cases, exchanges can be cancelled by clients before they are
completed, but the response was actually received by the client. The
response status information has been set by the application and the
response has been committed. For those cases, we shouldn't assume an
"UNKNOWN" value.
This commit assumes that committed responses have a response status set
by the application and that the observations should reflect that. From
now on, we only assume an "UNKNOWN" status if the response has not been
commited.
Fixes gh-31388
Due to the changes in gh-31341, if the repeat count in a SpEL
expression (using the repeat operator '*') is negative, we throw a
SpelEvaluationException with the MAX_REPEATED_TEXT_SIZE_EXCEEDED
message which is incorrect and misleading.
Prior to gh-31341, a negative repeat count resulted in an
IllegalArgumentException being thrown by String#repeat(), which was
acceptable in terms of diagnostics, but that did not make it
immediately clear to the user what the underlying cause was.
In light of the above, this commit improves diagnostics for a negative
repeated text count in SpEL expressions by throwing a
SpelEvaluationException with a new NEGATIVE_REPEATED_TEXT_COUNT error
message.
Closes gh-31342
If the resulting size of repeated text in a SpEL expression (using the
repeat operator '*') would exceed MAX_REPEATED_TEXT_SIZE, we currently
throw a SpelEvaluationException with the
MAX_REPEATED_TEXT_SIZE_EXCEEDED message.
However, if the calculation of the repeated text size results in
integer overflow, our max size check fails to detect that, and
String#repeat(int) throws a preemptive OutOfMemoryError from which the
application immediately recovers.
To improve diagnostics for users, this commit ensures that we
consistently throw a SpelEvaluationException with the
MAX_REPEATED_TEXT_SIZE_EXCEEDED message when integer overflow occurs.
Closes gh-31341
Prior to this commit the Spring Expression Language (SpEL) was able to
properly parse an expression that uses the safe navigation operator
(?.) with a method that has a `void` return type (for example,
"myObject?.doSomething()"); however, SpEL was not able to evaluate or
compile such expressions.
This commit addresses the evaluation issue by selectively not boxing
the exit type descriptor (for inclusion in the generated bytecode) when
the method's return type is `void`.
This commit addresses the compilation issue by pushing a null object
reference onto the stack in the generated byte code when the method's
return type is `void`.
Closes gh-27421
