Module mailbox 

N1 IntrusiveMailbox : lock-free LIFO mailbox for kernel-internal IPC.

This is a stack (LIFO) structure, not a FIFO queue. Messages are inserted at the head and popped from the head. This is acceptable for notification-style IPC between trusted kernel components (scheduler <==> VFS, scheduler <==> memory manager) where message ordering is not critical.

For FIFO-guaranteed IPC, use the [LockFreeRing] (N2) instead.

Safety

The mailbox uses tagged pointers (x86-64 canonical addresses) for ABA-safe lock-free push/pop. See tag_ptr and untag_ptr.

Structs

IntrusiveMailbox

MailboxMessage

A single message node in the intrusive linked list.

NodePool 🔒

A lock-free LIFO mailbox (stack) for kernel-internal IPC.

Enums

MailboxError

Errors from mailbox operations.

Constants

FREELIST_CAPACITY 🔒

Default number of pre-allocated node slots in the freelist. Chosen to cover the maximum expected number of in-flight N1 messages.

POOL_GEN_SHIFT 🔒

Shift for the generation counter in a tagged pool pointer.

POOL_PTR_MASK 🔒

Mask for the pointer portion of a tagged pool pointer.

PTR_MASK 🔒

TAG_MASK 🔒

TAG_SHIFT 🔒

Statics

TAG_COUNTER 🔒

Functions

tag_ptr 🔒

Encode a wrapped tag into the upper bits of a pointer value.

untag_ptr 🔒

Strip the tag and recover the real pointer.