Struct UrdHeader 

#[repr(C, align(64))]
pub struct UrdHeader {
    pub magic: u64,
    pub n_mailboxes: u64,
    pub owner_pid: AtomicU64,
    pub epoch: AtomicU64,
    pub _pad_meta: [u8; 24],
    pub rr_cursor: AtomicU64,
    pub _pad_rr: [u8; 56],
}

File header. Cache-line aligned.

Fields

magic: u64

Magic constant.

n_mailboxes: u64

Number of mailboxes (one per thief).

owner_pid: AtomicU64

Pid of the owner process; informational. Cleared on close_owner().

epoch: AtomicU64

Shutdown epoch counter.

_pad_meta: [u8; 24]

Padding to push rr_cursor to its own cache line.

rr_cursor: AtomicU64

Round-robin cursor the owner uses to pick the next target mailbox when no explicit target is supplied.

_pad_rr: [u8; 56]

Padding to round to two cache lines.