ConcurrentReferenceHashMap does not enforce visibility of cached EntrySet [SPR-16994]

[spring-projects-issues]

Juergen Hoeller opened SPR-16994 and commented

ConcurrentReferenceHashMap.entrySet() tries to reuse a cached EntrySet instance but stores it in a regular field which doesn't guarantee visibility to other threads. Operating against a volatile field is the cleaner arrangement here.

Also, ConcurrentReferenceHashMap does not implement isEmpty(), relying on AbstractMap's computation of the full size. This can be optimized by simply backing out once a non-empty hash segment has been found.

---

Affects: 4.3.18, 5.0.7

Issue Links:

• Memory leak in ConcurrentReferenceHashMap [SPR-11440] #16066 Memory leak in ConcurrentReferenceHashMap
• ConcurrentReferenceHashMap doesn't limit upper concurrency level [SPR-11720] #16342 ConcurrentReferenceHashMap doesn't limit upper concurrency level
• Inconsistent handling of null values through Java 8 accessors in ConcurrentReferenceHashMap [SPR-16584] #21126 Inconsistent handling of null values through Java 8 accessors in ConcurrentReferenceHashMap

Referenced from: commits 44b2657, ce0323f, 779cf8d

Backported to: 4.3.19