Struct Message 

pub struct Message {
    pub sender: u64,
    pub reply_cap: CapId,
    pub request_id: u64,
    pub tag: u16,
    pub payload: Arc<Value>,
}

Envelope carried in mailboxes and registers (Atomic Hop).

payload is a Value behind Arc so hops can carry Int, Str, Bytes, or nested messages. Mailbox byte budgets charge Value::memory_size of the whole hop, including the payload tree.

Security

• sender: FlowId stamped by the scheduler on bytecode Send / Ask (invariant S1). Not a capability.
• reply_cap: CapId minted at the hop boundary with SEND-only rights, holder = recipient. CapId::NONE means “no reply grant”.

See docs/security.md.

Fields

sender: u64

Authenticated origin FlowId (0 = trusted host / non-flow).

reply_cap: CapId

Capability granting SEND back to Self::sender, or CapId::NONE.

request_id: u64

Client correlation token; echoed on replies (Ask / S2).

tag: u16

Protocol discriminator (opaque to the VM).

payload: Arc<Value>

Application body (shared so hop clones are cheap).

Implementations

impl Message

pub fn new( sender: u64, request_id: u64, tag: u16, payload: impl Into<Value>, ) -> Self

Build an envelope. sender / reply_cap are placeholders until a bytecode hop is authenticated by the scheduler.

pub fn request(request_id: u64, tag: u16, payload: impl Into<Value>) -> Self

Outgoing hop from host Rust (sender / reply_cap filled on delivery).

pub fn reply_to(req: &Self, tag: u16, payload: impl Into<Value>) -> Self

Reply envelope echoing request_id from a received hop (host path).

pub fn down(monitor: u64, target_flow: u64, reason: u64) -> Self

Runtime lifecycle hop: monitor DOWN (tag == TAG_SYS_DOWN).

pub fn linked_exit(target_flow: u64, reason: u64) -> Self

Runtime lifecycle hop: Ask target exited (tag == TAG_SYS_EXIT).

pub fn is_down(&self) -> bool

pub fn is_exit(&self) -> bool

Trait Implementations

impl Clone for Message

fn clone(&self) -> Message

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Message

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Message

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<Message> for Value

fn from(m: Message) -> Self

Converts to this type from the input type.

impl PartialEq for Message

fn eq(&self, other: &Message) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Message