Struct ClockErrorBound

#[repr(C)]
pub struct ClockErrorBound {
    pub disruption_marker: u64,
    pub clock_disruption_support_enabled: bool,
    /* private fields */
}

Structure that holds the ClockErrorBound data captured at a specific point in time and valid until a subsequent point in time.

The ClockErrorBound structure supports calculating the actual bound on clock error at any time, using its now() method. The internal fields are not meant to be accessed directly.

Note that the timestamps in between which this ClockErrorBound data is valid are captured using a CLOCK_MONOTONIC_COARSE clock. The monotonic clock id is required to correctly measure the duration during which clock drift possibly accrues, and avoid events when the clock is set, smeared or affected by leap seconds.

The structure is shared across the Shared Memory segment and has a C representation to enforce this specific layout.

Fields

disruption_marker: u64

Disruption marker.

This value is incremented (by an unspecified delta) each time the clock has been disrupted. This count value is specific to a particular VM/EC2 instance.

clock_disruption_support_enabled: bool

Clock disruption support enabled flag.

This indicates whether or not the ClockBound daemon was started with a configuration that supports detecting clock disruptions.

Implementations

impl ClockErrorBound

pub fn new( as_of: TimeSpec, void_after: TimeSpec, bound_nsec: i64, disruption_marker: u64, max_drift_ppb: u32, clock_status: ClockStatus, clock_disruption_support_enabled: bool, ) -> ClockErrorBound

Create a new ClockErrorBound struct.

pub fn now(&self) -> Result<(TimeSpec, TimeSpec, ClockStatus), ShmError>

The ClockErrorBound equivalent of clock_gettime(), but with bound on accuracy.

Returns a pair of (earliest, latest) timespec between which current time exists. The interval width is twice the clock error bound (ceb) such that: (earliest, latest) = ((now - ceb), (now + ceb)) The function also returns a clock status to assert that the clock is being synchronized, or free-running, or …

Trait Implementations

impl Clone for ClockErrorBound

fn clone(&self) -> ClockErrorBound

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClockErrorBound

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

Formats the value using the given formatter.

impl Default for ClockErrorBound

fn default() -> Self

Get a default ClockErrorBound struct Equivalent to zero’ing this bit of memory

impl PartialEq for ClockErrorBound

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ClockErrorBound

impl StructuralPartialEq for ClockErrorBound