Spring Framework 5.2 M1 introduced a memory leak for applications using
@Async methods. Specifically, in a large test suite with multiple
ApplicationContexts that were closed (e.g., via @DirtiesContext,
@MockBean, or context cache eviction), the JVM process could run out of
memory.
Underlying cause: Due to a missing equals() implementation in Spring's
new AnnotationCandidateClassFilter, CGLIB's static cache of generated
classes indirectly retained references to BeanFactory instances for the
closed ApplicationContexts for the duration of the test suite.
This commit fixes this regression by introducing a proper equals()
implementation in AnnotationCandidateClassFilter. This commit also
introduces corresponding hashCode() and toString() implementations.
Closes gh-23571
e1e072b75c