Sounds to me like they could really do with a reverse mapping so that you have O(1) procedure to clean up the handles on exit. Linux had a similar issue with m

Sounds to me like they could really do with a reverse mapping so that you have O(1) procedure to clean up the handles on exit. Linux had a similar issue with memory maps (pte, vma, etc) when under memory pressure (i.e. needing to swap). In 2002 / 2003 successive reverse mapping (rmap) patches were added to the kernel so that a full memory map scan wasn't required to go from a memory object to a task and back again.