pmm_load.h File Reference

Load data structures. More...

#include <pthread.h>

Go to the source code of this file.

Data Structures
struct	pmm_loadhistory
struct	pmm_load

Typedefs
typedef struct pmm_loadhistory	PMM_Loadhistory
typedef struct pmm_load	PMM_Load

Functions
struct pmm_load *	new_load ()
struct pmm_loadhistory *	new_loadhistory ()
int	init_loadhistory (struct pmm_loadhistory *h, int size)
void	add_load (struct pmm_loadhistory *h, struct pmm_load *l)
int	check_loadhistory (struct pmm_loadhistory *h)
void	print_loadhistory (const char *output, struct pmm_loadhistory *h)
void	print_load (const char *output, struct pmm_load *l)

Detailed Description

Load data structures.

Data structures representing the load and load history of a system

Definition in file pmm_load.h.

Typedef Documentation

typedef struct pmm_load PMM_Load

this is a record of system load

typedef struct pmm_loadhistory PMM_Loadhistory

this is a circular array of load history, size determined at run time

Function Documentation

void add_load	(	struct pmm_loadhistory *	h,
		struct pmm_load *	l
	)

This function copies the structure l into the load history structure which is a circular array.

Parameters

h	pointer to the load history structure
l	pointer to the load to be copied into the next free/expired element of the circular array

Definition at line 120 of file pmm_load.c.

int check_loadhistory

(

struct pmm_loadhistory *

h

)

Do some sanity checking on the load history structure

Parameters

h	pointer to load history

Returns

1 if load history passes check, 0 if it fails

Definition at line 160 of file pmm_load.c.

int init_loadhistory	(	struct pmm_loadhistory *	h,
		int	size
	)

Function initialises the array and indexes that are used to store the load history (in a circular type array)

Parameters

h	pointer to a load history structure
size	size of the circular array

Returns

0 on success, -1 on failure

TODO check that history is not already allocated, free in this case first

Definition at line 90 of file pmm_load.c.

struct pmm_load* new_load ( )

read

initialized a new load observation structure

Returns

pointer to an allocated and intialized load structure

Definition at line 191 of file pmm_load.c.

struct pmm_loadhistory* new_loadhistory ( )

read

Allocates and initialises memory for a new load history structure. This is a circular array arrangement with pointers to the beginning and end. Iteration over the array is done using the modulus operator to wrap the physically beginning and end addresses.

note for a given size we must keep size+1 elements in the array. Thus we store two different sizes. 'size' refers to the number of accessible elements in the circular array. 'size_mod' refers to actual allocated elements in the array and is only to be used when iterating through the accessible elements using i+1size_mod. 'size_mod' will always be the accessible size 'size' + 1

Returns

pointer to a new loadhistory structure or NULL on failure

Definition at line 50 of file pmm_load.c.

void print_load	(	const char *	output,
		struct pmm_load *	l
	)

prints a single load observation

Parameters

output	output stream to print to
l	pointer to load structure to print

Definition at line 233 of file pmm_load.c.

void print_loadhistory	(	const char *	output,
		struct pmm_loadhistory *	h
	)

prints a load history sequence

Parameters

output	output stream to print to
h	pointer to the load history

Definition at line 211 of file pmm_load.c.