Struct ClockSyncer

pub struct ClockSyncer { /* private fields */ }

Stores the state of the source PTP clock (i.e., an open file descriptor to it), and provides ClockSyncer::sync to set on-demand the system-wide real-time (i.e., wall-clock time) clock to the time of that source PTP clock.

Implementations

impl ClockSyncer

pub fn with_ptp_clock(dev_ptp_path: impl AsRef<Path>) -> Result<Self, Error>

Create a new ClockSyncer, assuming the provided dev_ptp_path is the path to the device node (typically under /dev/) that refers to the source PTP clock.

Errors

• On failure to open(2) the provided source PTP clock device node.

Notes

It is up to the caller to provide a path to a device node that refers to a valid instance of a PTP clock. This is not checked upon ClockSyncer initialization, and failure to provide so will be manifested through Error::Clock errors in subsequent ClockSyncer::sync calls.

The auxiliary function verify_ptp_dev attempts to verify whether a path refers to a device node that corresponds to a PTP clock device.

Use ClockSyncer::with_kvm_clock (which calls find_ptp_kvm) to attempt to automatically find a device node of KVM’s paravirtualized PTP clock before constructing the ClockSyncer.

pub fn with_kvm_clock() -> Result<Self, Error>

Create a new ClockSyncer, by searching for the KVM PTP clock to be used as the source.

Errors

• On failure while looking for the KVM PTP clock via find_ptp_kvm.
• On failure to open(2) the KVM PTP clock device node via with_ptp_clock.

pub fn sync(&self) -> Result<(), Error>

Set the system-wide real-time clock to the time provided by the source PTP clock of this ClockSyncer.

Errors

• If clock_gettime(2) fails for the source PTP clock.
• If clock_settime(2) fails for the system-wide real-time clock.

pub fn try_clone(&self) -> Result<Self, Error>

Attempt to clone the ClockSyncer, by also dup(2)ing the underlying file descriptor of source PTP clock.

Errors

If OwnedFd::try_clone fails.

Panics

If dup(2) returns an error value not in [1, 4095].

Trait Implementations

impl Debug for ClockSyncer

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

Formats the value using the given formatter.