IT:AD:Patterns:Reference Downward Only
Summary
Software Circular Dependencies between modules are problematic due to the tight coupling of the mutually dependent modules which renders the separate re-use and testability of a single module impossible.
Circular Dependencies may also cause memory leaks by preventing certain very primitive automatic garbage collectors (those that use reference counting) from deallocating unused objects.
Recipe
After applying the recommendated IT:AD:Patterns:Minimal Dependency Cardinality pattern – to minimize circular dependencies – the same guidelines apply to DDD based applications as older architecture patterns:
Assembllies must reference Assemblies in the same or lower layers -- never higher layers.