resource.h File Reference

Basic definitions for resource operations. More...

#include <limits.h>
#include <sys/time.h>
#include <sys/types.h>

Go to the source code of this file.

Data Structures
struct	rlimit
struct	rusage

Macros
#define	RLIM_INFINITY   UINT_MAX
#define	RLIM_SAVED_MAX   RLIM_INFINITY
#define	RLIM_SAVED_CUR   RLIM_INFINITY

Typedefs
typedef unsigned int	rlim_t

Enumerations
enum	{ PRIO_PROCESS , PRIO_PGRP , PRIO_USER }
enum	{   RLIMIT_CORE , RLIMIT_CPU , RLIMIT_DATA , RLIMIT_FSIZE ,   RLIMIT_NOFILE , RLIMIT_STACK , RLIMIT_AS }
enum	{ RUSAGE_SELF , RUSAGE_CHILDREN }

Functions
int	getpriority (int which, id_t who)
	Obtain the nice value of a process, process group, or user.
int	setpriority (int which, id_t who, int value)
	Sets the nice value of a process, process group, or user.
int	getrlimit (int resource, struct rlimit *rlp)
	Gets the maximum resource consumption limits.
int	setrlimit (int resource, const struct rlimit *rlp)
	Sets the maximum resource consumption limits.
int	getrusage (int who, struct rusage *r_usage)
	Get information about cpu utilization.

Detailed Description

Basic definitions for resource operations.

This file provides a basic implementation of the POSIX/XSI standard for resource operations. These are meant to be per-process, so are basically stubs for the purposes of KOS which is single-process.

Macro Definition Documentation

RLIM_INFINITY

#define RLIM_INFINITY   UINT_MAX

RLIM_SAVED_CUR

#define RLIM_SAVED_CUR   RLIM_INFINITY

RLIM_SAVED_MAX

#define RLIM_SAVED_MAX   RLIM_INFINITY

Typedef Documentation

rlim_t

typedef unsigned int rlim_t

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
PRIO_PROCESS
PRIO_PGRP
PRIO_USER

anonymous enum

anonymous enum

Enumerator
RLIMIT_CORE
RLIMIT_CPU
RLIMIT_DATA
RLIMIT_FSIZE
RLIMIT_NOFILE
RLIMIT_STACK
RLIMIT_AS

anonymous enum

anonymous enum

Enumerator
RUSAGE_SELF
RUSAGE_CHILDREN

Function Documentation

getpriority()

int getpriority	(	int	which,
		id_t	who )

Obtain the nice value of a process, process group, or user.

In KOS we don't have a concept currently of any of these things, so this is effectively a stub that will only return a value if requested for the default/current id.

Parameters

which	Which type of ID to get the nice value of.
who	Only 0 is currently valid.

Return values

0	On success.
-1	On error, errno will be set as appropriate.

Error Conditions:

EINVAL - which was an invalid value. EINVAL - who was a value other than 0.

Referenced by main().

getrlimit()

int getrlimit	(	int	resource,
		struct rlimit *	rlp )

Gets the maximum resource consumption limits.

Everything will return RLIM_INFINITY as we impose no such limits.

Parameters

resource	The type of resource to get the rlimit for.
rlp	Where to place the rlimit data.

Return values

0	On success.
-1	On error, errno will be set as appropriate.

Error Conditions:

EINVAL - resource was an invalid value.

getrusage()

int getrusage	(	int	who,
		struct rusage *	r_usage )

Get information about cpu utilization.

For the purposes of this function, KOS is treated as having a single process that all threads are running under. As such RUSAGE_SELF will return user time that is the sum of all living threads and system time that is all the rest (IRQs + dead threads). RUSAGE_CHILDREN will return zero.

Parameters

who	RUSAGE_SELF or RUSAGE_CHILDREN.
r_usage	rusage data to be filled.

Return values

0	On success.
-1	On error, errno will be set as appropriate.

Error Conditions:

EINVAL - who was an invalid value.

Referenced by main().

setpriority()

int setpriority	(	int	which,
		id_t	who,
		int	value )

Sets the nice value of a process, process group, or user.

In KOS we don't have a concept currently of any of these things, so this is effectively a stub that will only set a value if requested for the default/current id. This also currently has no impact aside from changing the return of getpriority.

Parameters

which	Which type of ID to set the nice value of.
who	Only 0 is currently valid.
value	nice value to set.

Return values

0	On success.
-1	On error, errno will be set as appropriate.

Error Conditions:

EINVAL - which was an invalid value. EINVAL - who was a value other than 0.

Referenced by main().

setrlimit()

int setrlimit	(	int	resource,
		const struct rlimit *	rlp )

Sets the maximum resource consumption limits.

Just a stub. Errors on bad input, otherwise always succeeds.

Parameters

resource	The type of resource to set the rlimit for.
rlp	Ignored.

Return values

0	On success.
-1	On error, errno will be set as appropriate.

Error Conditions:

EINVAL - resource was an invalid value.