Struct LamportClock 

pub struct LamportClock { /* private fields */ }

Lamport Clock for happens-before ordering

Implements Lamport’s logical clocks for establishing causal relationships between events in a distributed tracing system.

Reference: “Time, Clocks, and the Ordering of Events in a Distributed System” Lamport, L. Communications of the ACM, 21(7), 558-565 (1978)

Properties

1. Transitivity: a → b ∧ b → c ⇒ a → c
2. Irreflexivity: ¬(a → a)
3. Timestamp consistency: a → b ⇒ timestamp(a) < timestamp(b)

Implementations

impl LamportClock

pub fn new() -> Self

Create a new Lamport clock starting at 0

pub fn with_initial_value(initial: u64) -> Self

Create a Lamport clock with a specific starting value

pub fn tick(&self) -> u64

Increment clock on local event

Returns the new timestamp after increment. Uses SeqCst ordering to ensure happens-before consistency.

pub fn sync(&self, remote_timestamp: u64) -> u64

Synchronize clock on message receive

Updates local clock to max(local, remote) + 1. Ensures received messages have higher timestamps than their causally preceding events.

pub fn now(&self) -> u64

Get current clock value without modifying it

pub fn happens_before(a: u64, b: u64) -> bool

Check if timestamp a happens-before timestamp b

Returns true if a < b (strict temporal ordering). Note: This is a simple timestamp comparison. Full happens-before semantics require checking causal chains (see UnifiedTrace).

Trait Implementations

impl Clone for LamportClock

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LamportClock

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

Formats the value using the given formatter.

impl Default for LamportClock

fn default() -> Self

Returns the “default value” for a type.