atomic.h File Reference

FreeRTOS atomic operation support. More...

#include <stdint.h>

Go to the source code of this file.

Macros
#define	ATOMIC_ENTER_CRITICAL()   portENTER_CRITICAL()
#define	ATOMIC_EXIT_CRITICAL()   portEXIT_CRITICAL()
#define	portFORCE_INLINE
#define	ATOMIC_COMPARE_AND_SWAP_SUCCESS   0x1U
#define	ATOMIC_COMPARE_AND_SWAP_FAILURE   0x0U

Functions
static portFORCE_INLINE uint32_t	Atomic_CompareAndSwap_u32 (uint32_t volatile *pulDestination, uint32_t ulExchange, uint32_t ulComparand)
	Performs an atomic compare-and-swap operation on the specified values. More...
static portFORCE_INLINE void *	Atomic_SwapPointers_p32 (void *volatile *ppvDestination, void *pvExchange)
	Atomically sets the address pointed to by *ppvDestination to the value of *pvExchange. More...
static portFORCE_INLINE uint32_t	Atomic_CompareAndSwapPointers_p32 (void *volatile *ppvDestination, void *pvExchange, void *pvComparand)
	Performs an atomic compare-and-swap operation on the specified pointer values. More...
static portFORCE_INLINE uint32_t	Atomic_Add_u32 (uint32_t volatile *pulAddend, uint32_t ulCount)
	Atomically adds count to the value of the specified pointer points to. More...
static portFORCE_INLINE uint32_t	Atomic_Subtract_u32 (uint32_t volatile *pulAddend, uint32_t ulCount)
	Atomically subtracts count from the value of the specified pointer pointers to. More...
static portFORCE_INLINE uint32_t	Atomic_Increment_u32 (uint32_t volatile *pulAddend)
	Atomically increments the value of the specified pointer points to. More...
static portFORCE_INLINE uint32_t	Atomic_Decrement_u32 (uint32_t volatile *pulAddend)
	Atomically decrements the value of the specified pointer points to. More...
static portFORCE_INLINE uint32_t	Atomic_OR_u32 (uint32_t volatile *pulDestination, uint32_t ulValue)
	Performs an atomic OR operation on the specified values. More...
static portFORCE_INLINE uint32_t	Atomic_AND_u32 (uint32_t volatile *pulDestination, uint32_t ulValue)
	Performs an atomic AND operation on the specified values. More...
static portFORCE_INLINE uint32_t	Atomic_NAND_u32 (uint32_t volatile *pulDestination, uint32_t ulValue)
	Performs an atomic NAND operation on the specified values. More...
static portFORCE_INLINE uint32_t	Atomic_XOR_u32 (uint32_t volatile *pulDestination, uint32_t ulValue)
	Performs an atomic XOR operation on the specified values. More...

Detailed Description

FreeRTOS atomic operation support.

This file implements atomic functions by disabling interrupts globally. Implementations with architecture specific atomic instructions can be provided under each compiler directory.

Macro Definition Documentation

ATOMIC_COMPARE_AND_SWAP_SUCCESS

#define ATOMIC_COMPARE_AND_SWAP_SUCCESS   0x1U

Compare and swap succeeded, swapped.

ATOMIC_COMPARE_AND_SWAP_FAILURE

#define ATOMIC_COMPARE_AND_SWAP_FAILURE   0x0U

Compare and swap failed, did not swap.

Function Documentation

Atomic_CompareAndSwap_u32()

static portFORCE_INLINE uint32_t Atomic_CompareAndSwap_u32 ( uint32_t volatile *  pulDestination, uint32_t  ulExchange, uint32_t  ulComparand  )

static

Performs an atomic compare-and-swap operation on the specified values.

Atomic compare-and-swap

Parameters

[in,out]	pulDestination	Pointer to memory location from where value is to be loaded and checked.
[in]	ulExchange	If condition meets, write this value to memory.
[in]	ulComparand	Swap condition.

Returns

Unsigned integer of value 1 or 0. 1 for swapped, 0 for not swapped.

Note

This function only swaps *pulDestination with ulExchange, if previous *pulDestination value equals ulComparand.

Atomic_SwapPointers_p32()

static portFORCE_INLINE void* Atomic_SwapPointers_p32 ( void *volatile *  ppvDestination, void *  pvExchange  )

static

Atomically sets the address pointed to by *ppvDestination to the value of *pvExchange.

Atomic swap (pointers)

Parameters

[in,out]	ppvDestination	Pointer to memory location from where a pointer value is to be loaded and written back to.
[in]	pvExchange	Pointer value to be written to *ppvDestination.

Returns

The initial value of *ppvDestination.

Atomic_CompareAndSwapPointers_p32()

static portFORCE_INLINE uint32_t Atomic_CompareAndSwapPointers_p32 ( void *volatile *  ppvDestination, void *  pvExchange, void *  pvComparand  )

static

Performs an atomic compare-and-swap operation on the specified pointer values.

Atomic compare-and-swap (pointers)

Parameters

[in,out]	ppvDestination	Pointer to memory location from where a pointer value is to be loaded and checked.
[in]	pvExchange	If condition meets, write this value to memory.
[in]	pvComparand	Swap condition.

Returns

Unsigned integer of value 1 or 0. 1 for swapped, 0 for not swapped.

Note

This function only swaps *ppvDestination with pvExchange, if previous *ppvDestination value equals pvComparand.

Atomic_Add_u32()

static portFORCE_INLINE uint32_t Atomic_Add_u32 ( uint32_t volatile *  pulAddend, uint32_t  ulCount  )

static

Atomically adds count to the value of the specified pointer points to.

Atomic add

Parameters

[in,out]	pulAddend	Pointer to memory location from where value is to be loaded and written back to.
[in]	ulCount	Value to be added to *pulAddend.

Returns

previous *pulAddend value.

Atomic_Subtract_u32()

static portFORCE_INLINE uint32_t Atomic_Subtract_u32 ( uint32_t volatile *  pulAddend, uint32_t  ulCount  )

static

Atomically subtracts count from the value of the specified pointer pointers to.

Atomic subtract

Parameters

[in,out]	pulAddend	Pointer to memory location from where value is to be loaded and written back to.
[in]	ulCount	Value to be subtract from *pulAddend.

Returns

previous *pulAddend value.

Atomic_Increment_u32()

static portFORCE_INLINE uint32_t Atomic_Increment_u32 ( uint32_t volatile *  pulAddend )

static

Atomically increments the value of the specified pointer points to.

Atomic increment

Parameters

[in,out]

pulAddend

Pointer to memory location from where value is to be loaded and written back to.

Returns

*pulAddend value before increment.

Atomic_Decrement_u32()

static portFORCE_INLINE uint32_t Atomic_Decrement_u32 ( uint32_t volatile *  pulAddend )

static

Atomically decrements the value of the specified pointer points to.

Atomic decrement

Parameters

[in,out]

pulAddend

Pointer to memory location from where value is to be loaded and written back to.

Returns

*pulAddend value before decrement.

Atomic_OR_u32()

static portFORCE_INLINE uint32_t Atomic_OR_u32 ( uint32_t volatile *  pulDestination, uint32_t  ulValue  )

static

Performs an atomic OR operation on the specified values.

Atomic OR

Parameters

[in,out]	pulDestination	Pointer to memory location from where value is to be loaded and written back to.
[in]	ulValue	Value to be ORed with *pulDestination.

Returns

The original value of *pulDestination.

Atomic_AND_u32()

static portFORCE_INLINE uint32_t Atomic_AND_u32 ( uint32_t volatile *  pulDestination, uint32_t  ulValue  )

static

Performs an atomic AND operation on the specified values.

Atomic AND

Parameters

[in,out]	pulDestination	Pointer to memory location from where value is to be loaded and written back to.
[in]	ulValue	Value to be ANDed with *pulDestination.

Returns

The original value of *pulDestination.

Atomic_NAND_u32()

static portFORCE_INLINE uint32_t Atomic_NAND_u32 ( uint32_t volatile *  pulDestination, uint32_t  ulValue  )

static

Performs an atomic NAND operation on the specified values.

Atomic NAND

Parameters

[in,out]	pulDestination	Pointer to memory location from where value is to be loaded and written back to.
[in]	ulValue	Value to be NANDed with *pulDestination.

Returns

The original value of *pulDestination.

Atomic_XOR_u32()

static portFORCE_INLINE uint32_t Atomic_XOR_u32 ( uint32_t volatile *  pulDestination, uint32_t  ulValue  )

static

Performs an atomic XOR operation on the specified values.

Atomic XOR

Parameters

[in,out]	pulDestination	Pointer to memory location from where value is to be loaded and written back to.
[in]	ulValue	Value to be XORed with *pulDestination.

Returns

The original value of *pulDestination.