carb::time::tsc_clock

Defined in carb/time/TscClock.h

class tsc_clock

Static class for a CPU time-stamp clock.

The functions and types within this class are used for sampling the CPU’s time-stamp counter—typically a clock- cycle resolution clock directly within the CPU hardware.

Public Types

using Sample = ::carb::Strong<uint64_t, struct SampleSig>

Type definition of a sample from the CPU time-stamp counter.

The time units of this are unspecified. Use Freq to determine the frequency of the time-stamp counter.

using Freq = ::carb::Strong<uint64_t, struct FreqSig>

The frequency of the timestamp counter, that is, the number of Samples per second.

Public Static Functions

static inline Sample sample() noexcept

Read a sample from the CPU time-stamp clock.

Note that this operation is intended to be as fast as possible to maintain accuracy.

Returns

a time-stamp Sample at the time the function is called.

static inline Freq frequency() noexcept

Computes the frequency of the CPU time-stamp clock.

The first call to this function can take longer as the CPU time-stamp clock is calibrated.

Note

This implementation assumes that the frequency never changes. Please verify with your CPU architecture that this assumption is correct.

Returns

the computed Freq of the CPU time-stamp clock.

template<class Duration>
static inline Duration duration(Sample older, Sample newer) noexcept

Computes the difference of two samples as a std::chrono::duration.

Template Parameters

Duration – a std::chrono::duration template to convert to.

Parameters
  • older – The older (starting) sample

  • newer – The newer (ending) sample

Returns

The difference in timestamps as the requested Duration representation