cosmos::OtherSchedulerSettings Class Reference

"OTHER" Scheduling Policy Settings. More...

#include <Scheduler.hxx>

Inheritance diagram for cosmos::OtherSchedulerSettings:

Public Member Functions
void	setNiceValue (int value)
	Sets the nice priority for the child process.
int	niceValue () const
Public Member Functions inherited from cosmos::SchedulerSettings
	SchedulerSettings (const SchedulerPolicy policy)
SchedulerPolicy	policy () const
void	apply (ProcessID pid) const
	Apply the current scheduler settings to the given process.

Static Public Member Functions
static constexpr int	minNiceValue ()
static constexpr int	maxNiceValue ()

Protected Member Functions
void	fillStruct (struct sched_attr &attr) const override
	Fill the given low level sched_attr struct with the current settings.
Protected Member Functions inherited from cosmos::SchedulerSettings

Protected Attributes
int	m_nice_prio = INVALID_NICE_PRIO
	The nice priority to apply to the child process, if any.
Protected Attributes inherited from cosmos::SchedulerSettings
SchedulerPolicy	m_policy = SchedulerPolicy::INVALID

Static Protected Attributes
static const int	INVALID_NICE_PRIO = OtherSchedulerSettings::maxNiceValue() + 1
	A constant denoting an invalid nice value.

Detailed Description

"OTHER" Scheduling Policy Settings.

Definition at line 67 of file Scheduler.hxx.

Constructor & Destructor Documentation

OtherSchedulerSettings()

cosmos::OtherSchedulerSettings::OtherSchedulerSettings ( )

inline

Definition at line 71 of file Scheduler.hxx.

                                 :
                        SchedulerSettings{SchedulerPolicy::OTHER}
        {}

Member Function Documentation

fillStruct()

void cosmos::OtherSchedulerSettings::fillStruct ( struct sched_attr & attr ) const

overrideprotectedvirtual

Fill the given low level sched_attr struct with the current settings.

Implements cosmos::SchedulerSettings.

Definition at line 59 of file Scheduler.cxx.

                                                              {
        SchedulerSettings::fillStruct(attr);
        attr.sched_nice = m_nice_prio;
}

maxNiceValue()

static constexpr int cosmos::OtherSchedulerSettings::maxNiceValue ( )

inlinestaticconstexpr

Definition at line 77 of file Scheduler.hxx.

{ return 19; }

minNiceValue()

static constexpr int cosmos::OtherSchedulerSettings::minNiceValue ( )

inlinestaticconstexpr

Definition at line 76 of file Scheduler.hxx.

{ return -20; }

niceValue()

int cosmos::OtherSchedulerSettings::niceValue ( ) const

inline

Definition at line 101 of file Scheduler.hxx.

{ return m_nice_prio; }

setNiceValue()

void cosmos::OtherSchedulerSettings::setNiceValue ( int value )

inline

Sets the nice priority for the child process.

The nice value provides some basic CPU time prioritization for processes. It doesn't offer any hard guarantees but provides some general tendency for preferring or disregarding a process when it comes to scheduling CPU time.

Currently this setting only affects newly created child processes, not one that is already running.

Lower nice values mean more CPU time resources for the process. See minNiceValue() and maxNiceValue() for the lower and upper bound of this value.

Note that on Linux this setting affects only a single thread as opposed to the complete process as POSIX mandates. Since this call currently only supports this setting for newly created child processes this aspect doesn't matter much, however, because the nice value will be inherited by child threads and processes alike.

Definition at line 99 of file Scheduler.hxx.

{ m_nice_prio = value; }

Member Data Documentation

INVALID_NICE_PRIO

int cosmos::OtherSchedulerSettings::INVALID_NICE_PRIO = OtherSchedulerSettings::maxNiceValue() + 1

staticconstexprprotected

A constant denoting an invalid nice value.

Definition at line 110 of file Scheduler.hxx.

m_nice_prio

int cosmos::OtherSchedulerSettings::m_nice_prio = INVALID_NICE_PRIO

protected

The nice priority to apply to the child process, if any.

Definition at line 112 of file Scheduler.hxx.

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

• include/proc/Scheduler.hxx
• src/proc/Scheduler.cxx