Module mux 

Multi-slot / multi-client concurrency for lease-backed RPC.

The RpcMuxClient and RpcMuxServer types multiplex several independent RPC slots into a single MemLease. Each slot has its own status byte so that multiple clients can have requests in flight simultaneously.

Slot wire layout

All slots are contiguous in the leased arena. Each slot is SLOT_HEADER_SIZE + slot_payload_size bytes:

[request_id: u64 LE (8B)]
[method_id:  u32 LE (4B)]
[status:     u8      (1B)]
[reserved:   [u8; 3] (3B)]   // alignment padding
[payload_len:u32 LE (4B)]
[payload:    [u8; slot_payload_size]]

SLOT_HEADER_SIZE = 20 bytes (8 + 4 + 1 + 3 + 4).

Slot i begins at byte offset i * (SLOT_HEADER_SIZE + slot_payload_size).

Structs

RpcMuxClient

Multi-slot RPC client.

RpcMuxServer

Multi-slot RPC server.

Constants

DEFAULT_NUM_SLOTS

Default number of slots in a mux arena.

DEFAULT_SLOT_PAYLOAD_SIZE

Default payload capacity per slot (bytes).

SLOT_HEADER_SIZE

Header size per slot: request_id(8) + method_id(4) + status(1) + reserved(3) + payload_len(4) = 20 bytes.