Struct CMClock 

pub struct CMClock { /* private fields */ }

Available on crate feature CMSync only.

A timing source object.

A clock represents a source of time information: generally, a piece of hardware that measures the passage of time. One example of a clock is the host time clock, accessible via CMClockGetHostTimeClock(). It measures time using the CPU system clock, which on Mac OS X is mach_absolute_time(). Every audio device can also be considered a clock since the audio samples that it outputs or inputs each have a defined duration (eg, 1/48000 of a second for 48 kHz audio).

CMClocks are read-only: they cannot be stopped or started, and the current time cannot be set. A CMClock has one primary function, CMClockGetTime, which tells what time it is now. Additionally, the CMSync infrastructure monitors relative drift between CMClocks.

See also Apple’s documentation

Implementations

impl CMClock

pub unsafe fn host_time_clock() -> CFRetained<CMClock>

Returns a reference to the singleton clock logically identified with host time.

On Mac OS X, the host time clock uses mach_absolute_time but returns a value with a large integer timescale (eg, nanoseconds).

pub unsafe fn convert_host_time_to_system_units(host_time: CMTime) -> u64

Available on crate feature CMTime only.

Converts a host time from CMTime to the host time’s native units.

This function performs a scale conversion, not a clock conversion. It can be more accurate than CMTimeConvertScale because the system units may have a non-integer timescale. On Mac OS X, this function converts to the units of mach_absolute_time.

pub unsafe fn make_host_time_from_system_units(host_time: u64) -> CMTime

Available on crate feature CMTime only.

Converts a host time from native units to CMTime.

The returned value will have a large integer timescale (eg, nanoseconds). This function handles situations where host time’s native units use a non-integer timescale. On Mac OS X, this function converts from the units of mach_absolute_time.

pub unsafe fn time(&self) -> CMTime

Available on crate feature CMTime only.

Retrieves the current time from a clock.

pub unsafe fn anchor_time( &self, clock_time_out: NonNull<CMTime>, reference_clock_time_out: NonNull<CMTime>, ) -> i32

Available on crate feature CMTime only.

Retrieves the current time from a clock and also the matching time from the clock’s reference clock.

To make practical use of this, you may need to know what the clock’s reference clock is.

Safety

• clock_time_out must be a valid pointer.
• reference_clock_time_out must be a valid pointer.

pub unsafe fn might_drift(&self, other_clock: &CMClock) -> bool

Indicates whether it is possible for two clocks to drift relative to each other.

pub unsafe fn invalidate(&self)

Makes the clock stop functioning.

After invalidation, the clock will return errors from all APIs. This should only be called by the “owner” of the clock, who knows (for example) that some piece of hardware has gone away, and the clock will no longer work (and might even crash).

Methods from Deref<Target = CFType>

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: ConcreteType,

Available on crate feature CMAttachment only.

Attempt to downcast the type to that of type T.

This is the reference-variant. Use CFRetained::downcast if you want to convert a retained type. See also ConcreteType for more details on which types support being converted to.

pub fn retain_count(&self) -> usize

Available on crate feature CMAttachment only.

Get the reference count of the object.

This function may be useful for debugging. You normally do not use this function otherwise.

Beware that some things (like CFNumbers, small CFStrings etc.) may not have a normal retain count for optimization purposes, and can return usize::MAX in that case.

Trait Implementations

impl AsRef<AnyObject> for CMClock

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<CFType> for CMClock

fn as_ref(&self) -> &CFType

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<CMClock> for CMClock

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for CMClock

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<CFType> for CMClock

fn borrow(&self) -> &CFType

Immutably borrows from an owned value.

impl ConcreteType for CMClock

fn type_id() -> CFTypeID

Returns the CFTypeID for CMClock.

impl Debug for CMClock

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

Formats the value using the given formatter.

impl Deref for CMClock

type Target = CFType

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for CMClock

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for CMClock

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl PartialEq for CMClock

fn eq(&self, other: &Self) -> 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 RefEncode for CMClock

const ENCODING_REF: Encoding

The Objective-C type-encoding for a reference of this type.

impl Type for CMClock

fn retain(&self) -> CFRetained<Self>

where Self: Sized,

Increment the reference count of the receiver.

fn as_concrete_TypeRef(&self) -> &Self

👎Deprecated: this is redundant

Helper for easier transition from the core-foundation crate.

unsafe fn wrap_under_get_rule(ptr: *const Self) -> CFRetained<Self>

where Self: Sized,

👎Deprecated: use CFRetained::retain

Helper for easier transition from the core-foundation crate.

fn as_CFTypeRef(&self) -> &CFType

where Self: AsRef<CFType>,

👎Deprecated: this is redundant (CF types deref to CFType)

Helper for easier transition from the core-foundation crate.

unsafe fn wrap_under_create_rule(ptr: *const Self) -> CFRetained<Self>

where Self: Sized,

👎Deprecated: use CFRetained::from_raw

Helper for easier transition from the core-foundation crate.

impl Eq for CMClock

impl Send for CMClock

impl Sync for CMClock