API Description

Atomic variables.

Atomic integers using relaxed memory ordering

Atomic integer types (odp_atomic_u32_t, odp_atomic_u64_t and odp_atomic_u128_t) can be used to implement e.g. shared counters. If not otherwise documented, operations in this API are implemented using RELAXED memory ordering (see memory order descriptions in the C11 specification). Relaxed operations do not provide synchronization or ordering for other memory accesses (initiated before or after the operation), only atomicity of the operation itself is guaranteed.

Operations with non-relaxed memory ordering

An operation with RELEASE memory ordering (odp_atomic_xxx_rel_xxx()) ensures that other threads loading the same atomic variable with ACQUIRE memory ordering see all stores (from the calling thread) that happened before this releasing store.

An operation with ACQUIRE memory ordering (odp_atomic_xxx_acq_xxx()) ensures that the calling thread sees all stores (done by the releasing thread) that happened before a RELEASE memory ordered store to the same atomic variable.

An operation with ACQUIRE-and-RELEASE memory ordering (odp_atomic_xxx_acq_rel_xxx()) combines the effects of ACQUIRE and RELEASE memory orders. A single operation acts as both an acquiring load and a releasing store.

Data Structures
union	odp_atomic_op_t
	Atomic operations. More...

Typedefs
typedef union odp_atomic_op_t	odp_atomic_op_t
	Atomic operations. More...

typedef struct odp_atomic_u128_s	odp_atomic_u128_t
	Atomic 128-bit unsigned integer. More...

typedef struct odp_atomic_u64_s	odp_atomic_u64_t
	Atomic 64-bit unsigned integer. More...

typedef struct odp_atomic_u32_s	odp_atomic_u32_t
	Atomic 32-bit unsigned integer. More...

Functions
void	odp_atomic_init_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Initialize atomic uint32 variable. More...

uint32_t	odp_atomic_load_u32 (odp_atomic_u32_t *atom)
	Load value of atomic uint32 variable. More...

void	odp_atomic_store_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Store value to atomic uint32 variable. More...

uint32_t	odp_atomic_fetch_add_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Fetch and add to atomic uint32 variable. More...

void	odp_atomic_add_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Add to atomic uint32 variable. More...

uint32_t	odp_atomic_fetch_sub_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Fetch and subtract from atomic uint32 variable. More...

void	odp_atomic_sub_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Subtract from atomic uint32 variable. More...

uint32_t	odp_atomic_fetch_inc_u32 (odp_atomic_u32_t *atom)
	Fetch and increment atomic uint32 variable. More...

void	odp_atomic_inc_u32 (odp_atomic_u32_t *atom)
	Increment atomic uint32 variable. More...

uint32_t	odp_atomic_fetch_dec_u32 (odp_atomic_u32_t *atom)
	Fetch and decrement atomic uint32 variable. More...

void	odp_atomic_dec_u32 (odp_atomic_u32_t *atom)
	Decrement atomic uint32 variable. More...

void	odp_atomic_max_u32 (odp_atomic_u32_t *atom, uint32_t new_max)
	Update maximum value of atomic uint32 variable. More...

void	odp_atomic_min_u32 (odp_atomic_u32_t *atom, uint32_t new_min)
	Update minimum value of atomic uint32 variable. More...

int	odp_atomic_cas_u32 (odp_atomic_u32_t atom, uint32_t old_val, uint32_t new_val)
	Compare and swap atomic uint32 variable. More...

uint32_t	odp_atomic_xchg_u32 (odp_atomic_u32_t *atom, uint32_t new_val)
	Exchange value of atomic uint32 variable. More...

void	odp_atomic_init_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Initialize atomic uint64 variable. More...

uint64_t	odp_atomic_load_u64 (odp_atomic_u64_t *atom)
	Load value of atomic uint64 variable. More...

void	odp_atomic_store_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Store value to atomic uint64 variable. More...

uint64_t	odp_atomic_fetch_add_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Fetch and add to atomic uint64 variable. More...

void	odp_atomic_add_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Add to atomic uint64 variable. More...

uint64_t	odp_atomic_fetch_sub_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Fetch and subtract from atomic uint64 variable. More...

void	odp_atomic_sub_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Subtract from atomic uint64 variable. More...

uint64_t	odp_atomic_fetch_inc_u64 (odp_atomic_u64_t *atom)
	Fetch and increment atomic uint64 variable. More...

void	odp_atomic_inc_u64 (odp_atomic_u64_t *atom)
	Increment atomic uint64 variable. More...

uint64_t	odp_atomic_fetch_dec_u64 (odp_atomic_u64_t *atom)
	Fetch and decrement atomic uint64 variable. More...

void	odp_atomic_dec_u64 (odp_atomic_u64_t *atom)
	Decrement atomic uint64 variable. More...

void	odp_atomic_max_u64 (odp_atomic_u64_t *atom, uint64_t new_max)
	Update maximum value of atomic uint64 variable. More...

void	odp_atomic_min_u64 (odp_atomic_u64_t *atom, uint64_t new_min)
	Update minimum value of atomic uint64 variable. More...

int	odp_atomic_cas_u64 (odp_atomic_u64_t atom, uint64_t old_val, uint64_t new_val)
	Compare and swap atomic uint64 variable. More...

uint64_t	odp_atomic_xchg_u64 (odp_atomic_u64_t *atom, uint64_t new_val)
	Exchange value of atomic uint64 variable. More...

void	odp_atomic_init_u128 (odp_atomic_u128_t *atom, odp_u128_t val)
	Initialize atomic odp_u128_t variable. More...

odp_u128_t	odp_atomic_load_u128 (odp_atomic_u128_t *atom)
	Load value of atomic odp_u128_t variable. More...

void	odp_atomic_store_u128 (odp_atomic_u128_t *atom, odp_u128_t val)
	Store value to atomic odp_u128_t variable. More...

int	odp_atomic_cas_u128 (odp_atomic_u128_t atom, odp_u128_t old_val, odp_u128_t new_val)
	Compare and swap atomic odp_u128_t variable. More...

uint32_t	odp_atomic_load_acq_u32 (odp_atomic_u32_t *atom)
	Load value of atomic uint32 variable using ACQUIRE memory ordering. More...

void	odp_atomic_store_rel_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Store value to atomic uint32 variable using RELEASE memory ordering. More...

void	odp_atomic_add_rel_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Add to atomic uint32 variable using RELEASE memory ordering. More...

void	odp_atomic_sub_rel_u32 (odp_atomic_u32_t *atom, uint32_t val)
	Subtract from atomic uint32 variable using RELEASE memory ordering. More...

int	odp_atomic_cas_acq_u32 (odp_atomic_u32_t atom, uint32_t old_val, uint32_t new_val)
	Compare and swap atomic uint32 variable using ACQUIRE memory ordering. More...

int	odp_atomic_cas_rel_u32 (odp_atomic_u32_t atom, uint32_t old_val, uint32_t new_val)
	Compare and swap atomic uint32 variable using RELEASE memory ordering. More...

int	odp_atomic_cas_acq_rel_u32 (odp_atomic_u32_t atom, uint32_t old_val, uint32_t new_val)
	Compare and swap atomic uint32 variable using ACQUIRE-and-RELEASE memory ordering. More...

uint64_t	odp_atomic_load_acq_u64 (odp_atomic_u64_t *atom)
	Load value of atomic uint64 variable using ACQUIRE memory ordering. More...

void	odp_atomic_store_rel_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Store value to atomic uint64 variable using RELEASE memory ordering. More...

void	odp_atomic_add_rel_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Add to atomic uint64 variable using RELEASE memory ordering. More...

void	odp_atomic_sub_rel_u64 (odp_atomic_u64_t *atom, uint64_t val)
	Subtract from atomic uint64 variable using RELEASE memory ordering. More...

int	odp_atomic_cas_acq_u64 (odp_atomic_u64_t atom, uint64_t old_val, uint64_t new_val)
	Compare and swap atomic uint64 variable using ACQUIRE memory ordering. More...

int	odp_atomic_cas_rel_u64 (odp_atomic_u64_t atom, uint64_t old_val, uint64_t new_val)
	Compare and swap atomic uint64 variable using RELEASE memory ordering. More...

int	odp_atomic_cas_acq_rel_u64 (odp_atomic_u64_t atom, uint64_t old_val, uint64_t new_val)
	Compare and swap atomic uint64 variable using ACQUIRE-and-RELEASE memory ordering. More...

int	odp_atomic_lock_free_u64 (odp_atomic_op_t *atomic_op)
	Query which atomic uint64 operations are lock-free. More...

int	odp_atomic_cas_acq_u128 (odp_atomic_u128_t atom, odp_u128_t old_val, odp_u128_t new_val)
	Compare and swap atomic odp_u128_t variable using ACQUIRE memory ordering. More...

int	odp_atomic_cas_rel_u128 (odp_atomic_u128_t atom, odp_u128_t old_val, odp_u128_t new_val)
	Compare and swap atomic odp_u128_t variable using RELEASE memory ordering. More...

int	odp_atomic_cas_acq_rel_u128 (odp_atomic_u128_t atom, odp_u128_t old_val, odp_u128_t new_val)
	Compare and swap atomic odp_u128_t variable using ACQUIRE-and-RELEASE memory ordering. More...

int	odp_atomic_lock_free_u128 (odp_atomic_op_t *atomic_op)
	Query which atomic odp_atomic_u128_t operations are lock-free. More...

Typedef Documentation

◆ odp_atomic_op_t

typedef union odp_atomic_op_t odp_atomic_op_t

Atomic operations.

Atomic operations listed in a bit field structure.

◆ odp_atomic_u128_t

odp_atomic_u128_t

Atomic 128-bit unsigned integer.

Atomic 128-bit unsigned integer

◆ odp_atomic_u64_t

odp_atomic_u64_t

Atomic 64-bit unsigned integer.

Atomic 64-bit unsigned integer

◆ odp_atomic_u32_t

odp_atomic_u32_t

Atomic 32-bit unsigned integer.

Atomic 32-bit unsigned integer

Function Documentation

◆ odp_atomic_init_u32()

void odp_atomic_init_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Initialize atomic uint32 variable.

Initializes the atomic variable with 'val'. This operation is not atomic. Application must ensure that there's no race condition while initializing the variable.

Parameters

atom	Pointer to atomic variable
val	Value to initialize the variable with

◆ odp_atomic_load_u32()

uint32_t odp_atomic_load_u32 ( odp_atomic_u32_t * atom )

Load value of atomic uint32 variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable

◆ odp_atomic_store_u32()

void odp_atomic_store_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Store value to atomic uint32 variable.

Parameters

atom	Pointer to atomic variable
val	Value to store in the variable

◆ odp_atomic_fetch_add_u32()

uint32_t odp_atomic_fetch_add_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Fetch and add to atomic uint32 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be added to the variable

Returns: Value of the variable before the addition

Examples: odp_atomic_perf.c, and odp_pktio_perf.c.

◆ odp_atomic_add_u32()

void odp_atomic_add_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Add to atomic uint32 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be added to the variable

Examples: odp_atomic_perf.c, odp_icache_perf.c, odp_ipfragreass.c, odp_packet_gen.c, odp_stress.c, and odp_timer_perf.c.

◆ odp_atomic_fetch_sub_u32()

uint32_t odp_atomic_fetch_sub_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Fetch and subtract from atomic uint32 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be subtracted from the variable

Returns: Value of the variable before the subtraction

Examples: odp_atomic_perf.c.

◆ odp_atomic_sub_u32()

void odp_atomic_sub_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Subtract from atomic uint32 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be subtracted from the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_fetch_inc_u32()

uint32_t odp_atomic_fetch_inc_u32 ( odp_atomic_u32_t * atom )

Fetch and increment atomic uint32 variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable before the increment

Examples: odp_atomic_perf.c.

◆ odp_atomic_inc_u32()

void odp_atomic_inc_u32 ( odp_atomic_u32_t * atom )

Increment atomic uint32 variable.

Parameters

atom	Pointer to atomic variable

Examples: odp_atomic_perf.c, odp_packet_gen.c, odp_timer_perf.c, and odp_traffic_mgmt.c.

◆ odp_atomic_fetch_dec_u32()

uint32_t odp_atomic_fetch_dec_u32 ( odp_atomic_u32_t * atom )

Fetch and decrement atomic uint32 variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable before the subtraction

Examples: odp_atomic_perf.c, and odp_sched_perf.c.

◆ odp_atomic_dec_u32()

void odp_atomic_dec_u32 ( odp_atomic_u32_t * atom )

Decrement atomic uint32 variable.

Parameters

atom	Pointer to atomic variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_max_u32()

void odp_atomic_max_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	new_max
	)

Update maximum value of atomic uint32 variable.

Compares value of atomic variable to the new maximum value. If the new value is greater than the current value, writes the new value into the variable.

Parameters

atom	Pointer to atomic variable
new_max	New maximum value to be written into the atomic variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_min_u32()

void odp_atomic_min_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	new_min
	)

Update minimum value of atomic uint32 variable.

Compares value of atomic variable to the new minimum value. If the new value is less than the current value, writes the new value into the variable.

Parameters

atom	Pointer to atomic variable
new_min	New minimum value to be written into the atomic variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_u32()

int odp_atomic_cas_u32	(	odp_atomic_u32_t *	atom,
		uint32_t *	old_val,
		uint32_t	new_val
	)

Compare and swap atomic uint32 variable.

Compares value of atomic variable to the value pointed by 'old_val'. If the values are equal, the operation writes 'new_val' into the atomic variable and returns success. The operation returns failure only when the values are not equal (strong CAS operation). The current value of atomic variable is written into 'old_val' on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_xchg_u32()

uint32_t odp_atomic_xchg_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	new_val
	)

Exchange value of atomic uint32 variable.

Atomically replaces the value of atomic variable with the new value. Returns the old value.

Parameters

atom	Pointer to atomic variable
new_val	New value of the atomic variable

Returns: Value of the variable before the operation

Examples: odp_atomic_perf.c.

◆ odp_atomic_init_u64()

void odp_atomic_init_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Initialize atomic uint64 variable.

Initializes the atomic variable with 'val'. This operation is not atomic. Application must ensure that there's no race condition while initializing the variable.

Parameters

atom	Pointer to atomic variable
val	Value to initialize the variable with

Examples: odp_atomic_perf.c, odp_classifier.c, odp_sched_perf.c, odp_stress.c, odp_switch.c, and odp_timer_accuracy.c.

◆ odp_atomic_load_u64()

uint64_t odp_atomic_load_u64 ( odp_atomic_u64_t * atom )

Load value of atomic uint64 variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable

Examples: odp_atomic_perf.c, odp_classifier.c, odp_sched_perf.c, odp_switch.c, and odp_timer_accuracy.c.

◆ odp_atomic_store_u64()

void odp_atomic_store_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Store value to atomic uint64 variable.

Parameters

atom	Pointer to atomic variable
val	Value to store in the variable

Examples: odp_atomic_perf.c, and odp_switch.c.

◆ odp_atomic_fetch_add_u64()

uint64_t odp_atomic_fetch_add_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Fetch and add to atomic uint64 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be added to the variable

Returns: Value of the variable before the addition

Examples: odp_atomic_perf.c.

◆ odp_atomic_add_u64()

void odp_atomic_add_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Add to atomic uint64 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be added to the variable

Examples: odp_atomic_perf.c, odp_classifier.c, and odp_sched_perf.c.

◆ odp_atomic_fetch_sub_u64()

uint64_t odp_atomic_fetch_sub_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Fetch and subtract from atomic uint64 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be subtracted from the variable

Returns: Value of the variable before the subtraction

Examples: odp_atomic_perf.c.

◆ odp_atomic_sub_u64()

void odp_atomic_sub_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Subtract from atomic uint64 variable.

Parameters

atom	Pointer to atomic variable
val	Value to be subtracted from the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_fetch_inc_u64()

uint64_t odp_atomic_fetch_inc_u64 ( odp_atomic_u64_t * atom )

Fetch and increment atomic uint64 variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable before the increment

Examples: odp_atomic_perf.c, odp_stress.c, and odp_timer_accuracy.c.

◆ odp_atomic_inc_u64()

void odp_atomic_inc_u64 ( odp_atomic_u64_t * atom )

Increment atomic uint64 variable.

Parameters

atom	Pointer to atomic variable

Examples: odp_atomic_perf.c, odp_classifier.c, and odp_timer_accuracy.c.

◆ odp_atomic_fetch_dec_u64()

uint64_t odp_atomic_fetch_dec_u64 ( odp_atomic_u64_t * atom )

Fetch and decrement atomic uint64 variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable before the decrement

Examples: odp_atomic_perf.c.

◆ odp_atomic_dec_u64()

void odp_atomic_dec_u64 ( odp_atomic_u64_t * atom )

Decrement atomic uint64 variable.

Parameters

atom	Pointer to atomic variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_max_u64()

void odp_atomic_max_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	new_max
	)

Update maximum value of atomic uint64 variable.

Compares value of atomic variable to the new maximum value. If the new value is greater than the current value, writes the new value into the variable.

Parameters

atom	Pointer to atomic variable
new_max	New maximum value to be written into the atomic variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_min_u64()

void odp_atomic_min_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	new_min
	)

Update minimum value of atomic uint64 variable.

Compares value of atomic variable to the new minimum value. If the new value is less than the current value, writes the new value into the variable.

Parameters

atom	Pointer to atomic variable
new_min	New minimum value to be written into the atomic variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_u64()

int odp_atomic_cas_u64	(	odp_atomic_u64_t *	atom,
		uint64_t *	old_val,
		uint64_t	new_val
	)

Compare and swap atomic uint64 variable.

Compares value of atomic variable to the value pointed by 'old_val'. If the values are equal, the operation writes 'new_val' into the atomic variable and returns success. The operation returns failure only when the values are not equal (strong CAS operation). The current value of atomic variable is written into 'old_val' on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_xchg_u64()

uint64_t odp_atomic_xchg_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	new_val
	)

Exchange value of atomic uint64 variable.

Atomically replaces the value of atomic variable with the new value. Returns the old value.

Parameters

atom	Pointer to atomic variable
new_val	New value of the atomic variable

Returns: Value of the variable before the operation

Examples: odp_atomic_perf.c.

◆ odp_atomic_init_u128()

void odp_atomic_init_u128	(	odp_atomic_u128_t *	atom,
		odp_u128_t	val
	)

Initialize atomic odp_u128_t variable.

Initializes the atomic variable with 'val'. This operation is not atomic. Application must ensure that there's no race condition while initializing the variable.

Parameters

atom	Pointer to atomic variable
val	Value to initialize the variable with

Examples: odp_atomic_perf.c, and odp_ipfragreass.c.

◆ odp_atomic_load_u128()

odp_u128_t odp_atomic_load_u128 ( odp_atomic_u128_t * atom )

Load value of atomic odp_u128_t variable.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_store_u128()

void odp_atomic_store_u128	(	odp_atomic_u128_t *	atom,
		odp_u128_t	val
	)

Store value to atomic odp_u128_t variable.

Parameters

atom	Pointer to atomic variable
val	Value to store in the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_u128()

int odp_atomic_cas_u128	(	odp_atomic_u128_t *	atom,
		odp_u128_t *	old_val,
		odp_u128_t	new_val
	)

Compare and swap atomic odp_u128_t variable.

Compares value of atomic variable to the value pointed by 'old_val'. If the values are equal, the operation writes 'new_val' into the atomic variable and returns success. The operation returns failure only when the values are not equal (strong CAS operation). The current value of atomic variable is written into 'old_val' on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_load_acq_u32()

uint32_t odp_atomic_load_acq_u32 ( odp_atomic_u32_t * atom )

Load value of atomic uint32 variable using ACQUIRE memory ordering.

Otherwise identical to odp_atomic_load_u32() but ensures ACQUIRE memory ordering.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable

Examples: odp_atomic_perf.c, and odp_timer_perf.c.

◆ odp_atomic_store_rel_u32()

void odp_atomic_store_rel_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Store value to atomic uint32 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_store_u32() but ensures RELEASE memory ordering.

Parameters

atom	Pointer to atomic variable
val	Value to store in the variable

Examples: odp_atomic_perf.c, and odp_timer_perf.c.

◆ odp_atomic_add_rel_u32()

void odp_atomic_add_rel_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Add to atomic uint32 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_add_u32() but ensures RELEASE memory ordering.

Parameters

atom	Pointer to atomic variable
val	Value to be added to the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_sub_rel_u32()

void odp_atomic_sub_rel_u32	(	odp_atomic_u32_t *	atom,
		uint32_t	val
	)

Subtract from atomic uint32 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_sub_u32() but ensures RELEASE memory ordering.

Parameters

atom	Pointer to atomic variable
val	Value to be subtracted from the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_acq_u32()

int odp_atomic_cas_acq_u32	(	odp_atomic_u32_t *	atom,
		uint32_t *	old_val,
		uint32_t	new_val
	)

Compare and swap atomic uint32 variable using ACQUIRE memory ordering.

Otherwise identical to odp_atomic_cas_u32() but ensures ACQUIRE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_rel_u32()

int odp_atomic_cas_rel_u32	(	odp_atomic_u32_t *	atom,
		uint32_t *	old_val,
		uint32_t	new_val
	)

Compare and swap atomic uint32 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_cas_u32() but ensures RELEASE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_acq_rel_u32()

int odp_atomic_cas_acq_rel_u32	(	odp_atomic_u32_t *	atom,
		uint32_t *	old_val,
		uint32_t	new_val
	)

Compare and swap atomic uint32 variable using ACQUIRE-and-RELEASE memory ordering.

Otherwise identical to odp_atomic_cas_u32() but ensures ACQUIRE-and-RELEASE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_load_acq_u64()

uint64_t odp_atomic_load_acq_u64 ( odp_atomic_u64_t * atom )

Load value of atomic uint64 variable using ACQUIRE memory ordering.

Otherwise identical to odp_atomic_load_u64() but ensures ACQUIRE memory ordering.

Parameters

atom	Pointer to atomic variable

Returns: Value of the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_store_rel_u64()

void odp_atomic_store_rel_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Store value to atomic uint64 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_store_u64() but ensures RELEASE memory ordering.

Parameters

atom	Pointer to atomic variable
val	Value to store in the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_add_rel_u64()

void odp_atomic_add_rel_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Add to atomic uint64 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_add_u64() but ensures RELEASE memory ordering.

Parameters

atom	Pointer to atomic variable
val	Value to be added to the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_sub_rel_u64()

void odp_atomic_sub_rel_u64	(	odp_atomic_u64_t *	atom,
		uint64_t	val
	)

Subtract from atomic uint64 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_sub_u64() but ensures RELEASE memory ordering.

Parameters

atom	Pointer to atomic variable
val	Value to be subtracted from the variable

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_acq_u64()

int odp_atomic_cas_acq_u64	(	odp_atomic_u64_t *	atom,
		uint64_t *	old_val,
		uint64_t	new_val
	)

Compare and swap atomic uint64 variable using ACQUIRE memory ordering.

Otherwise identical to odp_atomic_cas_u64() but ensures ACQUIRE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_rel_u64()

int odp_atomic_cas_rel_u64	(	odp_atomic_u64_t *	atom,
		uint64_t *	old_val,
		uint64_t	new_val
	)

Compare and swap atomic uint64 variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_cas_u64() but ensures RELEASE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_acq_rel_u64()

int odp_atomic_cas_acq_rel_u64	(	odp_atomic_u64_t *	atom,
		uint64_t *	old_val,
		uint64_t	new_val
	)

Compare and swap atomic uint64 variable using ACQUIRE-and-RELEASE memory ordering.

Otherwise identical to odp_atomic_cas_u64() but ensures ACQUIRE-and-RELEASE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_lock_free_u64()

int odp_atomic_lock_free_u64 ( odp_atomic_op_t * atomic_op )

Query which atomic uint64 operations are lock-free.

Lock-free implementations have higher performance and scale better than implementations using locks. User can decide to use e.g. uint32 atomic variables instead of uint64 to optimize performance on platforms that implement a performance critical operation using locks.

Init operations (e.g. odp_atomic_init_u64()) are not atomic. This function clears the op.init bit but will never set it to one.

Parameters

atomic_op Pointer to atomic operation structure for storing operation flags. All bits are initialized to zero during the operation. The parameter is ignored when NULL.

Return values

0	None of the operations are lock-free
1	Some of the operations are lock-free
2	All operations are lock-free

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_acq_u128()

int odp_atomic_cas_acq_u128	(	odp_atomic_u128_t *	atom,
		odp_u128_t *	old_val,
		odp_u128_t	new_val
	)

Compare and swap atomic odp_u128_t variable using ACQUIRE memory ordering.

Otherwise identical to odp_atomic_cas_u128() but ensures ACQUIRE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_rel_u128()

int odp_atomic_cas_rel_u128	(	odp_atomic_u128_t *	atom,
		odp_u128_t *	old_val,
		odp_u128_t	new_val
	)

Compare and swap atomic odp_u128_t variable using RELEASE memory ordering.

Otherwise identical to odp_atomic_cas_u128() but ensures RELEASE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_cas_acq_rel_u128()

int odp_atomic_cas_acq_rel_u128	(	odp_atomic_u128_t *	atom,
		odp_u128_t *	old_val,
		odp_u128_t	new_val
	)

Compare and swap atomic odp_u128_t variable using ACQUIRE-and-RELEASE memory ordering.

Otherwise identical to odp_atomic_cas_u128() but ensures ACQUIRE-and-RELEASE memory ordering on success. Memory ordering is RELAXED on failure.

Parameters

	atom	Pointer to atomic variable
[in,out]	old_val	Pointer to the old value of the atomic variable. Operation updates this value on failure.
	new_val	New value to be written into the atomic variable

Returns: 0 on failure, !0 on success

Examples: odp_atomic_perf.c.

◆ odp_atomic_lock_free_u128()

int odp_atomic_lock_free_u128 ( odp_atomic_op_t * atomic_op )

Query which atomic odp_atomic_u128_t operations are lock-free.

Lock-free implementations have higher performance and scale better than implementations using locks.

Init operations (e.g. odp_atomic_init_u128()) are not atomic. This function clears the op.init bit but will never set it to one.

Note: 128-bit atomic API includes only init, load, store and CAS operations.

Parameters

atomic_op Pointer to atomic operation structure for storing operation flags. All bits are initialized to zero during the operation. The parameter is ignored when NULL.

Return values

0	None of the 128-bit atomic operations are lock-free
1	Some of the 128-bit atomic operations are lock-free
2	All 128-bit atomic operations are lock-free

Examples: odp_atomic_perf.c.

API Description

Data Structures

Typedefs

Functions

Typedef Documentation

◆ odp_atomic_op_t

◆ odp_atomic_u128_t

◆ odp_atomic_u64_t

◆ odp_atomic_u32_t

Function Documentation

◆ odp_atomic_init_u32()

◆ odp_atomic_load_u32()

◆ odp_atomic_store_u32()

◆ odp_atomic_fetch_add_u32()

◆ odp_atomic_add_u32()

◆ odp_atomic_fetch_sub_u32()

◆ odp_atomic_sub_u32()

◆ odp_atomic_fetch_inc_u32()

◆ odp_atomic_inc_u32()

◆ odp_atomic_fetch_dec_u32()

◆ odp_atomic_dec_u32()

◆ odp_atomic_max_u32()

◆ odp_atomic_min_u32()

◆ odp_atomic_cas_u32()

◆ odp_atomic_xchg_u32()

◆ odp_atomic_init_u64()

◆ odp_atomic_load_u64()

◆ odp_atomic_store_u64()

◆ odp_atomic_fetch_add_u64()

◆ odp_atomic_add_u64()

◆ odp_atomic_fetch_sub_u64()

◆ odp_atomic_sub_u64()

◆ odp_atomic_fetch_inc_u64()

◆ odp_atomic_inc_u64()

◆ odp_atomic_fetch_dec_u64()

◆ odp_atomic_dec_u64()

◆ odp_atomic_max_u64()

◆ odp_atomic_min_u64()

◆ odp_atomic_cas_u64()

◆ odp_atomic_xchg_u64()

◆ odp_atomic_init_u128()

◆ odp_atomic_load_u128()

◆ odp_atomic_store_u128()

◆ odp_atomic_cas_u128()

◆ odp_atomic_load_acq_u32()

◆ odp_atomic_store_rel_u32()

◆ odp_atomic_add_rel_u32()

◆ odp_atomic_sub_rel_u32()

◆ odp_atomic_cas_acq_u32()

◆ odp_atomic_cas_rel_u32()

◆ odp_atomic_cas_acq_rel_u32()

◆ odp_atomic_load_acq_u64()

◆ odp_atomic_store_rel_u64()

◆ odp_atomic_add_rel_u64()

◆ odp_atomic_sub_rel_u64()

◆ odp_atomic_cas_acq_u64()

◆ odp_atomic_cas_rel_u64()

◆ odp_atomic_cas_acq_rel_u64()

◆ odp_atomic_lock_free_u64()

◆ odp_atomic_cas_acq_u128()

◆ odp_atomic_cas_rel_u128()

◆ odp_atomic_cas_acq_rel_u128()

◆ odp_atomic_lock_free_u128()