Base class for changing process scheduling options. More...

#include <Scheduler.hxx>

Inheritance diagram for cosmos::SchedulerSettings:

Public Member Functions
	SchedulerSettings (const SchedulerPolicy policy)

SchedulerPolicy	policy () const

void	apply (ProcessID pid) const
	Apply the current scheduler settings to the given process.

Protected Member Functions
virtual void	fillStruct (struct sched_attr &attr) const =0
	Fill the given low level sched_attr struct with the current settings.

Protected Attributes
SchedulerPolicy	m_policy = SchedulerPolicy::INVALID

Detailed Description

Base class for changing process scheduling options.

Specializations of this type can be used to create child processes with adjusted scheduling settings or to adjust the scheduling settings or existing processes.

Definition at line 36 of file Scheduler.hxx.

Constructor & Destructor Documentation

◆ SchedulerSettings() [1/2]

cosmos::SchedulerSettings::SchedulerSettings ( )

inline

Definition at line 39 of file Scheduler.hxx.

39{}

◆ SchedulerSettings() [2/2]

cosmos::SchedulerSettings::SchedulerSettings ( const SchedulerPolicy policy )

inlineexplicit

Definition at line 41 of file Scheduler.hxx.

                                                                 :
                        m_policy{policy}
        {}

Member Function Documentation

◆ apply()

void cosmos::SchedulerSettings::apply ( ProcessID pid ) const

Apply the current scheduler settings to the given process.

If the operation fails then an ApiError is thrown.

If pid is zero then the settings are applied to the calling process/thread.

Definition at line 15 of file Scheduler.cxx.

                                                 {
        struct sched_attr attrs;
        this->fillStruct(attrs);
 
        // not only the data structure is not commonly defined in the C
        // headers, also the system call is not available. So we need to do it
        // ourselves.
        //
        // the POSIX interface sched_setscheduler is probably available, but
        // only supports the priority property and FIFO/RR, nothing else.
        if (::syscall(__NR_sched_setattr, pid, &attrs, 0) != 0) {
                cosmos_throw (ApiError("sched_setattr()"));
        }
}

◆ fillStruct()

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

protectedpure virtual

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

Implemented in cosmos::OtherSchedulerSettings, and cosmos::RealTimeSchedulerSettings.

Definition at line 50 of file Scheduler.cxx.

                                                         {
        if (m_policy == SchedulerPolicy::INVALID) {
                cosmos_throw (UsageError("Tried to fill sched_attr for invalid policy"));
        }
        zero_object(attr);
        attr.size = sizeof(attr);
        attr.sched_policy = static_cast<int>(m_policy);
}

◆ policy()

SchedulerPolicy cosmos::SchedulerSettings::policy ( ) const

inline

Definition at line 45 of file Scheduler.hxx.

45{ return m_policy; }

Member Data Documentation

◆ m_policy

SchedulerPolicy cosmos::SchedulerSettings::m_policy = SchedulerPolicy::INVALID

protected

Definition at line 63 of file Scheduler.hxx.

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

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

Public Member Functions

Protected Member Functions

Protected Attributes