jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer Namespace Reference

Use the TSC timer to measure intervals. More...

Namespaces
namespace	private_

Classes
class	in_order
	Measure a time interval using derivatives of the CPU instruction RDTSC. More...
class	out_of_order
	Measure a time interval using the CPU instruction RDTSC. More...

Typedefs
using	element_type = std::uint64_t

Functions
double	TSC_to_microsec (element_type ticks) noexcept(true)
boost::posix_time::ptime	TSC_to_UTC (element_type ticks) noexcept(true)
double	pause_for_usec (double delay) noexcept(true)
	Busy wait for a certain period. More...

Detailed Description

Use the TSC timer to measure intervals.

To determine is the TSC is available or reliable, on Linux the contents of: /sys/devices/system/clocksource/clocksource0/available_clocksource should be examined. This also indicates if the TSCs between processors are synchronised [1], section 17.16.1.

[1] "Intel® 64 and IA-32 Architectures Developer's Manual", https://www-ssl.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-manual-325462.html

Typedef Documentation

element_type

using jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::element_type = typedef std::uint64_t

Definition at line 108 of file hp_timer.hpp.

Function Documentation

pause_for_usec()

double jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::pause_for_usec ( double  delay )

inlinenoexcept

Busy wait for a certain period.

Parameters

delay

In microseconds.

Returns

Delay achieved in microseconds.

Definition at line 233 of file hp_timer.hpp.

References jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::in_order::get_end(), jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::in_order::get_start(), and TSC_to_microsec().

Referenced by BOOST_AUTO_TEST_CASE(), and BOOST_AUTO_TEST_CASE_TEMPLATE().

TSC_to_microsec()

double jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::TSC_to_microsec ( element_type  ticks )

inlinenoexcept

Definition at line 212 of file hp_timer.hpp.

References jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::private_::ticks_per_microsec_details::mean.

Referenced by pause_for_usec(), and jmmcg::LIBJMMCG_VER_NAMESPACE::latency_timestamps_itf::timestamp::to_csv().

TSC_to_UTC()

boost::posix_time::ptime jmmcg::LIBJMMCG_VER_NAMESPACE::cpu_timer::TSC_to_UTC ( element_type  ticks )

inlinenoexcept

Definition at line 221 of file hp_timer.hpp.