utilities_api.h File Reference

The declarations in this header file contain utility definitions and function prototypes that are used within the SDK but are not part of the API. More...

#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Macros
#define	CDI_NANOSECONDS_PER_SECOND   (1000000000UL)
	Number of nanoseconds in a second.
#define	CONTAINER_OF(ptr, type, member)    (type*)( (char*)(ptr) - offsetof(type, member) )
#define	CONTAINER_FROM(ptr, type, member_pointed_to, desired_member)    (type*)( (char*)(ptr) + (offsetof(type, desired_member) - offsetof(type, member_pointed_to)) )
#define	CDI_ARRAY_ELEMENT_COUNT(array)   ((int)(sizeof(array) / sizeof(array[0])))
#define	CDI_MIN(a, b)   (((a) < (b)) ? (a) : (b))
#define	CDI_MAX(a, b)   (((a) > (b)) ? (a) : (b))
#define	CDI_INVALID_ENUM_VALUE   (-1)
	Define used to represent an invalid enum value.

Functions
static const char *	CdiGetEmptyStringIfNull (const char *source_str)

Detailed Description

The declarations in this header file contain utility definitions and function prototypes that are used within the SDK but are not part of the API.

Macro Definition Documentation

CDI_ARRAY_ELEMENT_COUNT

#define CDI_ARRAY_ELEMENT_COUNT

(

array

)

((int)(sizeof(array) / sizeof(array[0])))

Evaluates to the number of elements in a statically sized array.

Parameters

array

The name of the statically sized array variable whose element count is to be returned.

Returns

The number of elements that comprise the array variable.

CDI_MAX

#define CDI_MAX	(		a,
			b )   (((a) > (b)) ? (a) : (b))

Evaluates to the larger of the two quantities. This is implemented as a macro so that it can be used for any type of arguments so long as they can be compared using the greater than operator. Care must be taken when using this macro as the arguments may get evaluated multiple times; don't specify an auto-incremented variable, for example.

CDI_MIN

#define CDI_MIN	(		a,
			b )   (((a) < (b)) ? (a) : (b))

Evaluates to the smaller of the two quantities. This is implemented as a macro so that it can be used for any type of arguments so long as they can be compared using the less than operator. Care must be taken when using this macro as the arguments may get evaluated multiple times; don't specify an auto-incremented variable, for example.

CONTAINER_FROM

#define CONTAINER_FROM	(		ptr,
			type,
			member_pointed_to,
			desired_member )    (type*)( (char*)(ptr) + (offsetof(type, desired_member) - offsetof(type, member_pointed_to)) )

This macro is used to locate a pointer to a desired member in a structure that is located in the same containing structure.

Parameters

ptr	The address of the known contained structure member.
type	The type of the containing structure.
member_pointed_to	The name of the member within the containing structure whose address is ptr.
desired_member	The name of the contained member whose address is to be returned.

Returns

The address of the containing structure.

CONTAINER_OF

#define CONTAINER_OF	(		ptr,
			type,
			member )    (type*)( (char*)(ptr) - offsetof(type, member) )

This macro is used to locate a pointer to the start of a structure given a pointer to the specified member in the structure.

Parameters

ptr	The address of the contained structure member.
type	The type of the containing structure.
member	The name of the member within the containing structure whose address is ptr.

Returns

The address of the containing structure.

Function Documentation

CdiGetEmptyStringIfNull()

static const char * CdiGetEmptyStringIfNull ( const char * source_str )

inlinestatic

Return an empty string if the string specified is NULL, otherwise the specified string is returned.

Parameters

source_str

Pointer to source string

Returns

Pointer to source_str if it is not NULL, otherwise returns a pointer to an empty string.