ComputationalLoad Class Reference

#include "/Werk/devel/lumi/tests/vault/gear/test-chain-load.hpp"

Description

A calibratable CPU load to be invoked from a node job functor.

Two distinct methods for load generation are provided

• tight loop with arithmetics in register
• repeatedly accessing and adding memory marked as volatile The timeBase multiplied with the given scaleStep´ determines the actual run time. When using the _memory method_ (useAllocation), a heap block ofstaleStep*sizeBase` is used, and the number of repetitions is chosen such as to match the given timing goal.

  Note

  since performance depends on the platform, it is mandatory to invoke the self calibration at least once prior to use. Performing the calibration with default base settings is acceptable, since mostly the overall expense is growing linearly; obviously the calibration is more precisely however when using the actual timeBase and sizeBase of the intended usage. The calibration watches processing speed in a microbenchmark with LOAD_BENCHMARK_RUNS repetitions; the result is stored in a static variable and can thus be reused.

Definition at line 1319 of file test-chain-load.hpp.

Public Member Functions
double	benchmark (uint scaleStep=1)
void	calibrate ()
double	invoke (uint scaleStep=1)
	cause a delay by computational load
bool	isCalibrated () const
void	maybeCalibrate ()

Public Attributes
size_t	sizeBase = LOAD_DEFAULT_MEM_SIZE
microseconds	timeBase = LOAD_DEFAULT_TIME
bool	useAllocation = false

Private Types
using	Sink = volatile size_t

Private Member Functions
auto	allocNeeded (uint scaleStep)
void	causeComputationLoad (uint scaleStep)
void	causeMemProcessLoad (uint scaleStep)
double	determineSpeed ()
void	performIncrementalCalibration ()
uint64_t	roundsNeeded (uint scaleStep)
Private Member Functions inherited from MoveAssign
	MoveAssign (MoveAssign &&)=default
	MoveAssign (MoveAssign const &)=delete
MoveAssign &	operator= (MoveAssign &&)=default
MoveAssign &	operator= (MoveAssign const &)=delete

Static Private Member Functions
static double &	computationSpeed (bool mem)

Member Function Documentation

computationSpeed()

static double& computationSpeed ( bool  mem )

inlinestaticprivate

Parameters

mem	in iterations/µs

Definition at line 1325 of file test-chain-load.hpp.

References vault::gear::test::anonymous_namespace{test-chain-load.hpp}::LOAD_DEFAULT_MEM_SIZE, vault::gear::test::anonymous_namespace{test-chain-load.hpp}::LOAD_DEFAULT_TIME, and vault::gear::test::anonymous_namespace{test-chain-load.hpp}::LOAD_SPEED_BASELINE.

benchmark()

double benchmark ( uint  scaleStep = 1 )

inline

Returns

averaged runtime in current configuration

Definition at line 1349 of file test-chain-load.hpp.

Referenced by TestChainLoad_test::verify_computation_load().

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The documentation for this class was generated from the following file:

• test-chain-load.hpp