Configuration

#include <hpk/configuration.hpp>

An instance of Configuration is passed to makeFactory() to provide parameters and their values for constructing a factory.

Parameter	Default value	Notes
architecture	Architecture::detect	value is an hpk::Architecture
threads	0 => detectCores()	int, where -n => ncores - n
teams	0 => detectPackages()	int, where -n => npkgs - n
l1size	0 => detectDataCache(1).size	int, L1 size measured in KiB
l2size	0 => detectDataCache(2).size	int, L2 size measured in KiB
l3size	0 => detectDataCache(3).size	int, L3 size measured in KiB

The threads parameter sets the maximum number of threads that can be used by a compute object. Note that the default is the number of cores, not the number of cpus. On a core with hyperthreading, you can try setting threads to the value returned by detectCpus().

The teams parameter may be used by a factory to determine how to divvy up the threads among work items. Similarly, cache sizes are used to guide how the problem is decomposed into work items.

See Also:

Architecture

Detection

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ENUMERATION

enum class hpk::Parameter

Enumerates the parameters that can be set in a Configuration.

Values:

enumerator invalid

Parameter is invalid.

enumerator architecture

value has type hpk::Architecture

enumerator threads

value has type int (max total number of threads)

enumerator teams

value has type int (number of teams of threads)

enumerator l1size

value has type int (L1 size measured in KiB)

enumerator l2size

value has type int (L2 size measured in KiB)

enumerator l3size

value has type int (L3 size measured in KiB)

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CLASS

class Configuration

A collection of configuration settings.

A Configuration is a container for parameters and their associated values.

Example:

hpk::Configuration cfg{ hpk::Architecture::avx2,
                       {hpk::Parameter::threads, 1},
                       {hpk::Parameter::l1size, 32} };

Public Functions

Configuration() = default

Default constructor.

inline Configuration(std::initializer_list<ConfigItem> init)

Constructs a Configuration instance from an initializer list. Each ConfigItem in the list is either an Architecture or a key and integer value, {Parameter, int}. If multiple entries in the list have the same parameter, it is unspecified which one will be used.

inline Configuration(const std::vector<ConfigItem> &v)

Constructs a Configuration instance from a vector by copying its contents.

inline Configuration(std::vector<ConfigItem> &&v) noexcept

Constructs a Configuration instance from a vector using move semantics.

Architecture getArchitecture() const

Returns the Architecture that was set in this configuration. If an architecture was not set, it returns Architecture::detect.

int get(Parameter p) const

Returns the value of the specified parameter that was set in this configuration. If a value for the parameter was not set, it returns 0.

std::string toString() const

Returns a string description of a Configuration.

Friends

friend std::ostream &operator<<(std::ostream &os, const Configuration &cfg)

Overload for ostream’s << operator for a Configuration.