Module cap 

Cap — cap enum + shared constants.

Cap types and their inner storage use the default Global allocator (= std heap on host, talc on guest via #[global_allocator]).

CapRef is an Arc-backed handle

A CapRef is the entry-lifetime token for CacheDirectory.instances. Clone bumps an inner Arc refcount; Drop decrements it. CacheDirectory itself owns one CapRef per live entry alongside the data; when external holders all drop their clones, the directory’s sweep_instances finds entries whose stored CapRef has strong_count == 1 and removes them. No callback-on-drop, no deadlock discipline.

Cap::CNode slots and Cap::Instance.root_cnode hold CapHashOrRef::Ref(CapRef) directly, so cloning a Cap deep-bumps every nested handle and dropping a Cap deep-releases them. Recursive cleanup is automatic via Rust’s Drop semantics; cycles are structurally impossible (data-flow principle: no shared mutable state across Instance boundaries).

Structs

CapRef

Cache-local lifetime handle to a working Cap::Instance in CacheDirectory.instances. Clone bumps the refcount; the directory’s sweep_instances reclaims entries whose only holder is the directory itself. Two separate CacheDirectory instances produce independent CapRef id namespaces — refs must not cross caches.

TypeCap

Cap::Type payload. Pure identifier; no owned content, so no allocator parameter needed.

Enums

Cap

One of the five v3 cap kinds.

CapHashOrRef

Slot/field reference: either a content-addressed blob in cache.blobs or a mutable working entry in cache.instances.

CapKind

Discriminant for Cap. Useful for matching, error messages, and places where the payload is irrelevant.

Constants

MAX_ENDPOINTS

Maximum number of endpoints per Image.

MAX_SOURCE_DEPTH

Maximum depth of a MemoryMapping.source_path. v3 cap graphs stay shallow; eight is plenty.

NUM_REGS

Number of PVM general-purpose registers (φ[0]..φ[12]).

Type Aliases

CapHash

32-byte digest used for all v3 cap identity / content hashes.