Bitfields of arbitrary length. More...

Detailed Description

Bitfields of arbitrary length.

The bitfields in this module have their most significant bytes first and their most significant bits within each byte of the bitfield also first.

Files
file	bitfield.h
	Bitfield operations on bitfields of arbitrary length.

Macros
#define	BITFIELD(NAME, SIZE)
	Declare a bitfield of a given size.

Functions
static void	bf_set (uint8_t field[], size_t idx)
	Set the bit to 1.

static void	bf_set_atomic (uint8_t field[], size_t idx)
	Atomically set the bit to 1.

static void	bf_unset (uint8_t field[], size_t idx)
	Clear the bit.

static void	bf_unset_atomic (uint8_t field[], size_t idx)
	Atomically clear the bit.

static void	bf_toggle (uint8_t field[], size_t idx)
	Toggle the bit.

static void	bf_toggle_atomic (uint8_t field[], size_t idx)
	Atomically toggle the bit.

static bool	bf_isset (const uint8_t field[], size_t idx)
	Check if the bet is set.

static void	bf_or (uint8_t out[], const uint8_t a[], const uint8_t b[], size_t len)
	Perform a bitwise OR operation on two bitfields `out = a \| b`

static void	bf_or_atomic (uint8_t out[], const uint8_t a[], const uint8_t b[], size_t len)
	Atomically perform a bitwise OR operation on two bitfields `out = a \| b`

static void	bf_and (uint8_t out[], const uint8_t a[], const uint8_t b[], size_t len)
	Perform a bitwise AND operation on two bitfields `out = a & b`

static void	bf_and_atomic (uint8_t out[], const uint8_t a[], const uint8_t b[], size_t len)
	Atomically perform a bitwise AND operation on two bitfields `out = a & b`

static void	bf_xor (uint8_t out[], const uint8_t a[], const uint8_t b[], size_t len)
	Perform a bitwise XOR operation on two bitfields `out = a ^ b`

static void	bf_xor_atomic (uint8_t out[], const uint8_t a[], const uint8_t b[], size_t len)
	Atomically perform a bitwise XOR operation on two bitfields `out = a ^ b`

static void	bf_inv (uint8_t out[], const uint8_t a[], size_t len)
	Perform a bitwise NOT operation on a bitfield `out = ~a`

static void	bf_inv_atomic (uint8_t out[], const uint8_t a[], size_t len)
	Atomically perform a bitwise NOT operation on a bitfield `out = ~a`

int	bf_get_unset (uint8_t field[], size_t len)
	Atomically get the number of an unset bit and set it.

int	bf_find_first_set (const uint8_t field[], size_t size)
	Get the index of the first set bit in the field.

int	bf_find_first_unset (const uint8_t field[], size_t size)
	Get the index of the zero bit in the field.

void	bf_set_all (uint8_t field[], size_t size)
	Set all bits in the bitfield to 1.

static void	bf_set_all_atomic (uint8_t field[], size_t size)
	Atomically set all bits in the bitfield to 1.

void	bf_clear_all (uint8_t field[], size_t size)
	Clear all bits in the bitfield to 0.

static void	bf_clear_all_atomic (uint8_t field[], size_t size)
	Atomically clear all bits in the bitfield to 0.

unsigned	bf_popcnt (const uint8_t field[], size_t size)
	Count set bits in the bitfield.

Macro Definition Documentation

◆ BITFIELD

#define BITFIELD	(		NAME,
			SIZE )

Value:

uint8_t NAME[((SIZE) + 7) / 8]

Declare a bitfield of a given size.

Note: SIZE should be a constant expression. This avoids variable length arrays.

Definition at line 43 of file bitfield.h.

Function Documentation

◆ bf_and()

static void bf_and	(	uint8_t	out[],
		const uint8_t	a[],
		const uint8_t	b[],
		size_t	len )

inlinestatic

Perform a bitwise AND operation on two bitfields out = a & b

Precondition: The size of a, b and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The first bitfield
[in]	b	The second bitfield
[in]	len	The number of bits in the bitfields

Definition at line 186 of file bitfield.h.

◆ bf_and_atomic()

static void bf_and_atomic	(	uint8_t	out[],
		const uint8_t	a[],
		const uint8_t	b[],
		size_t	len )

inlinestatic

Atomically perform a bitwise AND operation on two bitfields out = a & b

Precondition: The size of a, b and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The first bitfield
[in]	b	The second bitfield
[in]	len	The number of bits in the bitfields

Definition at line 208 of file bitfield.h.

◆ bf_clear_all()

void bf_clear_all	(	uint8_t	field[],
		size_t	size )

Clear all bits in the bitfield to 0.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

◆ bf_clear_all_atomic()

static void bf_clear_all_atomic	(	uint8_t	field[],
		size_t	size )

inlinestatic

Atomically clear all bits in the bitfield to 0.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

Definition at line 371 of file bitfield.h.

◆ bf_find_first_set()

int bf_find_first_set	(	const uint8_t	field[],
		size_t	size )

Get the index of the first set bit in the field.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

Returns: number of the first set bit; -1 if no bit is set

◆ bf_find_first_unset()

int bf_find_first_unset	(	const uint8_t	field[],
		size_t	size )

Get the index of the zero bit in the field.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

Returns: number of the first unset bit; -1 if all bits are set

◆ bf_get_unset()

int bf_get_unset	(	uint8_t	field[],
		size_t	len )

Atomically get the number of an unset bit and set it.

This function can be used to record e.g., empty entries in an array.

Parameters

[in,out]	field	The bitfield
[in]	len	The number of bits in the bitfield to consider

Returns: number of bit that was set; -1 if no bit was unset

◆ bf_inv()

static void bf_inv	(	uint8_t	out[],
		const uint8_t	a[],
		size_t	len )

inlinestatic

Perform a bitwise NOT operation on a bitfield out = ~a

Precondition: The size of a and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The bitfield to invert
[in]	len	The number of bits in the bitfield

Definition at line 273 of file bitfield.h.

◆ bf_inv_atomic()

static void bf_inv_atomic	(	uint8_t	out[],
		const uint8_t	a[],
		size_t	len )

inlinestatic

Atomically perform a bitwise NOT operation on a bitfield out = ~a

Precondition: The size of a and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The bitfield to invert
[in]	len	The number of bits in the bitfield

Definition at line 294 of file bitfield.h.

◆ bf_isset()

static bool bf_isset	(	const uint8_t	field[],
		size_t	idx )

inlinestatic

Check if the bet is set.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to check

Definition at line 123 of file bitfield.h.

◆ bf_or()

static void bf_or	(	uint8_t	out[],
		const uint8_t	a[],
		const uint8_t	b[],
		size_t	len )

inlinestatic

Perform a bitwise OR operation on two bitfields out = a | b

Precondition: The size of a, b and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The first bitfield
[in]	b	The second bitfield
[in]	len	The number of bits in the bitfields

Definition at line 142 of file bitfield.h.

◆ bf_or_atomic()

static void bf_or_atomic	(	uint8_t	out[],
		const uint8_t	a[],
		const uint8_t	b[],
		size_t	len )

inlinestatic

Atomically perform a bitwise OR operation on two bitfields out = a | b

Precondition: The size of a, b and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The first bitfield
[in]	b	The second bitfield
[in]	len	The number of bits in the bitfields

Definition at line 164 of file bitfield.h.

◆ bf_popcnt()

unsigned bf_popcnt	(	const uint8_t	field[],
		size_t	size )

Count set bits in the bitfield.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

Returns: number of '1' bits in the bitfield

◆ bf_set()

static void bf_set	(	uint8_t	field[],
		size_t	idx )

inlinestatic

Set the bit to 1.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to set

Definition at line 51 of file bitfield.h.

◆ bf_set_all()

void bf_set_all	(	uint8_t	field[],
		size_t	size )

Set all bits in the bitfield to 1.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

◆ bf_set_all_atomic()

static void bf_set_all_atomic	(	uint8_t	field[],
		size_t	size )

inlinestatic

Atomically set all bits in the bitfield to 1.

Parameters

[in]	field	The bitfield
[in]	size	The number of bits in the bitfield

Definition at line 350 of file bitfield.h.

◆ bf_set_atomic()

static void bf_set_atomic	(	uint8_t	field[],
		size_t	idx )

inlinestatic

Atomically set the bit to 1.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to set

Definition at line 62 of file bitfield.h.

◆ bf_toggle()

static void bf_toggle	(	uint8_t	field[],
		size_t	idx )

inlinestatic

Toggle the bit.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to toggle

Definition at line 99 of file bitfield.h.

◆ bf_toggle_atomic()

static void bf_toggle_atomic	(	uint8_t	field[],
		size_t	idx )

inlinestatic

Atomically toggle the bit.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to toggle

Definition at line 110 of file bitfield.h.

◆ bf_unset()

static void bf_unset	(	uint8_t	field[],
		size_t	idx )

inlinestatic

Clear the bit.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to clear

Definition at line 75 of file bitfield.h.

◆ bf_unset_atomic()

static void bf_unset_atomic	(	uint8_t	field[],
		size_t	idx )

inlinestatic

Atomically clear the bit.

Parameters

[in,out]	field	The bitfield
[in]	idx	The number of the bit to clear

Definition at line 86 of file bitfield.h.

◆ bf_xor()

static void bf_xor	(	uint8_t	out[],
		const uint8_t	a[],
		const uint8_t	b[],
		size_t	len )

inlinestatic

Perform a bitwise XOR operation on two bitfields out = a ^ b

Precondition: The size of a, b and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The first bitfield
[in]	b	The second bitfield
[in]	len	The number of bits in the bitfields

Definition at line 230 of file bitfield.h.

◆ bf_xor_atomic()

static void bf_xor_atomic	(	uint8_t	out[],
		const uint8_t	a[],
		const uint8_t	b[],
		size_t	len )

inlinestatic

Atomically perform a bitwise XOR operation on two bitfields out = a ^ b

Precondition: The size of a, b and out must be at least len bits

Note: This operation will also affect unused bits of the bytes that make up the bitfield.

Parameters

[out]	out	The resulting bitfield
[in]	a	The first bitfield
[in]	b	The second bitfield
[in]	len	The number of bits in the bitfields

Definition at line 252 of file bitfield.h.

Detailed Description

Files

Macros

Functions

Macro Definition Documentation

◆ BITFIELD

Function Documentation

◆ bf_and()

◆ bf_and_atomic()

◆ bf_clear_all()

◆ bf_clear_all_atomic()

◆ bf_find_first_set()

◆ bf_find_first_unset()

◆ bf_get_unset()

◆ bf_inv()

◆ bf_inv_atomic()

◆ bf_isset()

◆ bf_or()

◆ bf_or_atomic()

◆ bf_popcnt()

◆ bf_set()

◆ bf_set_all()

◆ bf_set_all_atomic()

◆ bf_set_atomic()

◆ bf_toggle()

◆ bf_toggle_atomic()

◆ bf_unset()

◆ bf_unset_atomic()

◆ bf_xor()

◆ bf_xor_atomic()