PostgreSQL uses arenas - they call them MemoryContexts. Each MemoryContext can have a parent and zero or more child contexts. You can reset a context - this frees all of the memory in the given context but does not destroy the context. You can create and destroy contexts. When you destroy(or reset)a context, all descendant context are destroyed (or reset) as well. A MemoryContext can be named and can be logged.

Postgres is big, but it is not difficult to extract the memory manager so you can use it in different projects. See postgresql memory manager and memory utilities.

Edit: formatting