Trait PlatformClock 

pub trait PlatformClock {
    // Required methods
    fn clock_ns() -> u64;
    fn clock_resolution_ns() -> u64;

    // Provided method
    fn epoch_us() -> u64 { ... }
}

Monotonic clock.

The most critical platform primitive. Must be backed by a hardware timer or OS tick — never by a software counter that only advances when polled.

Required Methods

fn clock_ns() -> u64

Monotonic nanoseconds since a platform-defined epoch. Never decreases. See <nros/platform.h> for the full contract (RFC-0073).

fn clock_resolution_ns() -> u64

Granularity of Self::clock_ns in nanoseconds: the smallest non-zero difference two successive reads can report. Non-zero, and constant after platform init.

Provided Methods

fn epoch_us() -> u64

Microseconds since the UNIX epoch, or 0 when this platform has no wall-clock source. See <nros/platform.h> for the full contract (issue 0758).

DEFAULTED to 0 deliberately. Every existing port is correct without changing a line: none of them has an epoch source today, and 0 is precisely the honest answer. Making this a required method would have forced eleven ports to write 0 by hand, which is the same information spelled eleven times plus eleven chances to write something else.

It is also the difference between an ABI addition that is a no-op for ports and one that breaks every image that has not caught up — and the C side has no such default, so a port implemented in C DOES say 0 explicitly.

Unlike Self::clock_ns this is not monotonic: a port that acquires its epoch after boot jumps when it does.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl PlatformClock for CffiPlatform

fn epoch_us() -> u64

issue 0758 — forwards to the C symbol. NOT defaulted here: a C port that supplies the symbol must be able to answer, and one that does not returns 0 from its own definition. Taking the trait default instead would silently ignore a C implementation that exists.

fn clock_ns() -> u64

fn clock_resolution_ns() -> u64

Implementors