stdatomic.h File Reference

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Macros
#define	LOCK_PREFIX   "\n\tlock; "
	The prefix used to lock.
#define	barrier()
	Compile read-write barrier. More...
#define	cpu_relax()
	Pause instruction to prevent excess processor bus usage. More...

Typedefs
typedef volatile unsigned	atomic_t
	Standard structure for atomic operations (see below for volatile explanation).

Functions
static int	atomic_set_and_test (atomic_t *ptr, int value)
	Atomically sets value at ptr. More...
static void	atomic_set (atomic_t *ptr, int value)
	Atomically set the value pointed by ptr to value. More...
static int	atomic_read (const atomic_t *ptr)
	Atomically read the value pointed by ptr. More...
static int	atomic_add (atomic_t *ptr, int value)
	Atomically add value to the value pointed by ptr. More...
static int	atomic_sub (atomic_t *ptr, int value)
	Atomically subtract value from the value pointed by ptr. More...
static int	atomic_inc (atomic_t *ptr)
	Atomically increment the value at ptr. More...
static int	atomic_dec (atomic_t *ptr)
	Atomically decrement the value at ptr. More...
static int	atomic_add_negative (atomic_t *ptr, int value)
	Atomically add value to ptr and checks if the result is negative. More...
static int	atomic_sub_and_test (atomic_t *ptr, int value)
	Atomically subtract value from ptr and checks if the result is zero. More...
static int	atomic_inc_and_test (atomic_t *ptr)
	Atomically increment ptr and checks if the result is zero. More...
static int	atomic_dec_and_test (atomic_t *ptr)
	Atomically decrement ptr and checks if the result is zero. More...
static void	set_bit (int offset, volatile unsigned long *base)
	Atomically sets a bit in memory, using Bit Test And Set (bts). More...
static void	clear_bit (int offset, volatile unsigned long *base)
	Atomically clears a bit in memory. More...
static int	test_bit (int offset, volatile unsigned long *base)
	Atomically tests a bit in memory. More...

Detailed Description

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Macro Definition Documentation

barrier

#define barrier

(

)

Value:

                                       __asm__ __volatile__("" \
                                       :  \
                                       :  \
                                       : "memory")

Compile read-write barrier.

cpu_relax

#define cpu_relax

(

)

Value:

                                         __asm__ __volatile__("pause\n" \
                                         :         \
                                         :         \
                                         : "memory")

Pause instruction to prevent excess processor bus usage.

Function Documentation

atomic_add()

static int atomic_add ( atomic_t *  ptr, int  value  )

inlinestatic

Atomically add value to the value pointed by ptr.

Parameters

ptr	the pointer we are working with.
value	the value we need to add.

Returns

the result of the operation.

atomic_add_negative()

static int atomic_add_negative ( atomic_t *  ptr, int  value  )

inlinestatic

Atomically add value to ptr and checks if the result is negative.

Parameters

ptr	the pointer we are working with.
value	the value we need to add.

Returns

true if the result is negative, false otherwise.

atomic_dec()

static int atomic_dec ( atomic_t *  ptr )

inlinestatic

Atomically decrement the value at ptr.

Parameters

ptr	the pointer we are working with.

Returns

the result of the operation.

atomic_dec_and_test()

static int atomic_dec_and_test ( atomic_t *  ptr )

inlinestatic

Atomically decrement ptr and checks if the result is zero.

Parameters

ptr	the pointer we are working with.

Returns

true if the result is zero, false otherwise.

atomic_inc()

static int atomic_inc ( atomic_t *  ptr )

inlinestatic

Atomically increment the value at ptr.

Parameters

ptr	the pointer we are working with.

Returns

the result of the operation.

atomic_inc_and_test()

static int atomic_inc_and_test ( atomic_t *  ptr )

inlinestatic

Atomically increment ptr and checks if the result is zero.

Parameters

ptr	the pointer we are working with.

Returns

true if the result is zero, false otherwise.

atomic_read()

static int atomic_read ( const atomic_t *  ptr )

inlinestatic

Atomically read the value pointed by ptr.

Parameters

ptr	the pointer we are working with.

Returns

the value we read.

atomic_set()

static void atomic_set ( atomic_t *  ptr, int  value  )

inlinestatic

Atomically set the value pointed by ptr to value.

Parameters

ptr	the pointer we are working with.
value	the value we need to set.

atomic_set_and_test()

static int atomic_set_and_test ( atomic_t *  ptr, int  value  )

inlinestatic

Atomically sets value at ptr.

Parameters

ptr	the pointer we are working with.
value	the value to set.

Returns

The final value of the atomic variable.

atomic_sub()

static int atomic_sub ( atomic_t *  ptr, int  value  )

inlinestatic

Atomically subtract value from the value pointed by ptr.

Parameters

ptr	the pointer we are working with.
value	the value we need to subtract.

Returns

the result of the operation.

atomic_sub_and_test()

static int atomic_sub_and_test ( atomic_t *  ptr, int  value  )

inlinestatic

Atomically subtract value from ptr and checks if the result is zero.

Parameters

ptr	the pointer we are working with.
value	the value we need to subtract.

Returns

true if the result is zero, false otherwise.

clear_bit()

static void clear_bit ( int  offset, volatile unsigned long *  base  )

inlinestatic

Atomically clears a bit in memory.

Parameters

offset	The offset to the bit.
base	The base address.

set_bit()

static void set_bit ( int  offset, volatile unsigned long *  base  )

inlinestatic

Atomically sets a bit in memory, using Bit Test And Set (bts).

Parameters

offset	The offset to the bit.
base	The base address.

test_bit()

static int test_bit ( int  offset, volatile unsigned long *  base  )

inlinestatic

Atomically tests a bit in memory.

Parameters

offset	The offset to the bit.
base	The base address.

Returns

1 if the bit is set, 0 otherwise.