bitarray.h File Reference

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

Go to the source code of this file.

Data Structures
struct	sys_bitarray

Macros
#define	SYS_BITARRAY_DEFINE(name, total_bits)
	Create a bitarray object. More...

Typedefs
typedef struct sys_bitarray	sys_bitarray_t

Functions
int	sys_bitarray_set_bit (sys_bitarray_t *bitarray, size_t bit)
int	sys_bitarray_clear_bit (sys_bitarray_t *bitarray, size_t bit)
int	sys_bitarray_test_bit (sys_bitarray_t *bitarray, size_t bit, int *val)
int	sys_bitarray_test_and_set_bit (sys_bitarray_t *bitarray, size_t bit, int *prev_val)
int	sys_bitarray_test_and_clear_bit (sys_bitarray_t *bitarray, size_t bit, int *prev_val)
int	sys_bitarray_alloc (sys_bitarray_t *bitarray, size_t num_bits, size_t *offset)
int	sys_bitarray_free (sys_bitarray_t *bitarray, size_t num_bits, size_t offset)
bool	sys_bitarray_is_region_set (sys_bitarray_t *bitarray, size_t num_bits, size_t offset)
bool	sys_bitarray_is_region_cleared (sys_bitarray_t *bitarray, size_t num_bits, size_t offset)
int	sys_bitarray_set_region (sys_bitarray_t *bitarray, size_t num_bits, size_t offset)
int	sys_bitarray_clear_region (sys_bitarray_t *bitarray, size_t num_bits, size_t offset)

Macro Definition Documentation

SYS_BITARRAY_DEFINE

#define SYS_BITARRAY_DEFINE	(		name,
			total_bits
	)

Value:

        uint32_t _sys_bitarray_bundles_##name                           \
                [(((total_bits + 8 - 1) / 8) + sizeof(uint32_t) - 1)    \
                 / sizeof(uint32_t)] = {0U};                            \
        sys_bitarray_t name = {                                         \
                .num_bits = total_bits,                                 \
                .num_bundles = (((total_bits + 8 - 1) / 8)              \
                                + sizeof(uint32_t) - 1)                 \
                               / sizeof(uint32_t),                      \
                .bundles = _sys_bitarray_bundles_##name,                \
        }

Create a bitarray object.

Parameters

name	Name of the bitarray object.
total_bits	Total number of bits in this bitarray object.

Typedef Documentation

sys_bitarray_t

typedef struct sys_bitarray sys_bitarray_t

Function Documentation

sys_bitarray_alloc()

int sys_bitarray_alloc	(	sys_bitarray_t *	bitarray,
		size_t	num_bits,
		size_t *	offset
	)

Allocate bits in a bit array

This finds a number of bits (num_bits) in a contiguous of previosly unallocated region. If such a region exists, the bits are marked as allocated and the offset to the start of this region is returned via offset.

Parameters

[in]	bitarray	Bitarray struct
[in]	num_bits	Number of bits to allocate
[out]	offset	Offset to the start of allocated region if successful

Return values

0	Allocation successful
-EINVAL	Invalid argument (e.g. allocating more bits than the bitarray has, trying to allocate 0 bits, etc.)
-ENOSPC	No contiguous region big enough to accommodate the allocation

sys_bitarray_clear_bit()

int sys_bitarray_clear_bit	(	sys_bitarray_t *	bitarray,
		size_t	bit
	)

Clear a bit in a bit array

Parameters

[in]	bitarray	Bitarray struct
[in]	bit	The bit to be cleared

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to clear exceeds the number of bits in bit array, etc.)

sys_bitarray_clear_region()

int sys_bitarray_clear_region	(	sys_bitarray_t *	bitarray,
		size_t	num_bits,
		size_t	offset
	)

Clear all bits in a region.

This clears the number of bits (num_bits) in region starting from offset.

Parameters

bitarray	Bitarray struct
num_bits	Number of bits to test
offset	Starting bit position to test

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to set exceeds the number of bits in bit array, etc.)

sys_bitarray_free()

int sys_bitarray_free	(	sys_bitarray_t *	bitarray,
		size_t	num_bits,
		size_t	offset
	)

Free bits in a bit array

This marks the number of bits (num_bits) starting from offset as no longer allocated.

Parameters

bitarray	Bitarray struct
num_bits	Number of bits to free
offset	Starting bit position to free

Return values

0	Free is successful
-EINVAL	Invalid argument (e.g. try to free more bits than the bitarray has, trying to free 0 bits, etc.)
-EFAULT	The bits in the indicated region are not all allocated.

sys_bitarray_is_region_cleared()

bool sys_bitarray_is_region_cleared	(	sys_bitarray_t *	bitarray,
		size_t	num_bits,
		size_t	offset
	)

Test if bits in a region is all cleared.

This tests if the number of bits (num_bits) in region starting from offset are all cleared.

Parameters

bitarray	Bitarray struct
num_bits	Number of bits to test
offset	Starting bit position to test

Return values

true	All bits are cleared.
false	Not all bits are cleared.

sys_bitarray_is_region_set()

bool sys_bitarray_is_region_set	(	sys_bitarray_t *	bitarray,
		size_t	num_bits,
		size_t	offset
	)

Test if bits in a region is all set.

This tests if the number of bits (num_bits) in region starting from offset are all set.

Parameters

bitarray	Bitarray struct
num_bits	Number of bits to test
offset	Starting bit position to test

Return values

true	All bits are set.
false	Not all bits are set.

sys_bitarray_set_bit()

int sys_bitarray_set_bit	(	sys_bitarray_t *	bitarray,
		size_t	bit
	)

Set a bit in a bit array

Parameters

[in]	bitarray	Bitarray struct
[in]	bit	The bit to be set

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to set exceeds the number of bits in bit array, etc.)

sys_bitarray_set_region()

int sys_bitarray_set_region	(	sys_bitarray_t *	bitarray,
		size_t	num_bits,
		size_t	offset
	)

Set all bits in a region.

This sets the number of bits (num_bits) in region starting from offset.

Parameters

bitarray	Bitarray struct
num_bits	Number of bits to test
offset	Starting bit position to test

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to set exceeds the number of bits in bit array, etc.)

sys_bitarray_test_and_clear_bit()

int sys_bitarray_test_and_clear_bit	(	sys_bitarray_t *	bitarray,
		size_t	bit,
		int *	prev_val
	)

Test the bit and clear it

Parameters

[in]	bitarray	Bitarray struct
[in]	bit	The bit to be tested and cleared
[out]	prev_val	Previous value of the bit (0 or 1)

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to test exceeds the number of bits in bit array, etc.)

sys_bitarray_test_and_set_bit()

int sys_bitarray_test_and_set_bit	(	sys_bitarray_t *	bitarray,
		size_t	bit,
		int *	prev_val
	)

Test the bit and set it

Parameters

[in]	bitarray	Bitarray struct
[in]	bit	The bit to be tested and set
[out]	prev_val	Previous value of the bit (0 or 1)

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to test exceeds the number of bits in bit array, etc.)

sys_bitarray_test_bit()

int sys_bitarray_test_bit	(	sys_bitarray_t *	bitarray,
		size_t	bit,
		int *	val
	)

Test whether a bit is set or not

Parameters

[in]	bitarray	Bitarray struct
[in]	bit	The bit to be tested
[out]	val	The value of the bit (0 or 1)

Return values

0	Operation successful
-EINVAL	Invalid argument (e.g. bit to test exceeds the number of bits in bit array, etc.)