CMClock
An object that represents a source of time.
Declaration
class CMClockOverview
A clock represents a source of time information: 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 in macOS is mach_absolute_time(). Every audio device is also a clock because the audio samples that it outputs or inputs each have a defined duration (for example, 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.