hf::SeqlockSnapshot< T > Class Template Reference

#include <SeqlockSnapshot.h>

Inheritance diagram for hf::SeqlockSnapshot< T >:

Public Member Functions
	SeqlockSnapshot () noexcept=default
	~SeqlockSnapshot () override
	SeqlockSnapshot (const SeqlockSnapshot &)=delete
SeqlockSnapshot &	operator= (const SeqlockSnapshot &)=delete
void	Publish (const T &value) noexcept override
	Atomically replace the published snapshot with value.
uint32_t	Read (T &out) const noexcept override
	Read the latest coherent snapshot.
uint32_t	Seq () const noexcept override
	Monotonic change counter (each successful Publish adds 2).
bool	WaitForChange (uint32_t timeout_ms) noexcept override
	Block up to timeout_ms waiting for any change since the last call to WaitForChange / ClearWaitEvent.
bool	ClearWaitEvent () noexcept override
	Drop any pending change-signal without waiting.
Public Member Functions inherited from hf::SnapshotReader< T >
virtual	~SnapshotReader () noexcept=default
Public Member Functions inherited from hf::SnapshotWriter< T >
virtual	~SnapshotWriter () noexcept=default

Private Member Functions
void	SignalChange_ () noexcept
bool	EnsureEventGroup_ () noexcept

Private Attributes
std::atomic< uint32_t >	seq_ {0}
T	payload_ {}
OS_EventGroup	event_group_ {}
bool	event_group_created_ {false}

Static Private Attributes
static constexpr OS_Ulong	kEventBit_ = 0x1U

Constructor & Destructor Documentation

SeqlockSnapshot() [1/2]

template<typename T >

hf::SeqlockSnapshot< T >::SeqlockSnapshot ( )

defaultnoexcept

~SeqlockSnapshot()

template<typename T >

hf::SeqlockSnapshot< T >::~SeqlockSnapshot ( )

inlineoverride

SeqlockSnapshot() [2/2]

template<typename T >

hf::SeqlockSnapshot< T >::SeqlockSnapshot ( const SeqlockSnapshot< T > &  )

delete

Member Function Documentation

ClearWaitEvent()

template<typename T >

bool hf::SeqlockSnapshot< T >::ClearWaitEvent ( )

inlineoverridevirtualnoexcept

Drop any pending change-signal without waiting.

Implements hf::SnapshotReader< T >.

EnsureEventGroup_()

template<typename T >

bool hf::SeqlockSnapshot< T >::EnsureEventGroup_ ( )

inlineprivatenoexcept

operator=()

template<typename T >

SeqlockSnapshot & hf::SeqlockSnapshot< T >::operator= ( const SeqlockSnapshot< T > &  )

delete

Publish()

template<typename T >

void hf::SeqlockSnapshot< T >::Publish ( const T &  value )

inlineoverridevirtualnoexcept

Atomically replace the published snapshot with value.

Single-writer only. Increments Seq() by 2 and signals waiters.

Implements hf::SnapshotWriter< T >.

Read()

template<typename T >

uint32_t hf::SeqlockSnapshot< T >::Read ( T &  out ) const

inlineoverridevirtualnoexcept

Read the latest coherent snapshot.

Returns

current sequence (post-read); always even on success.

Implements hf::SnapshotReader< T >.

Seq()

template<typename T >

uint32_t hf::SeqlockSnapshot< T >::Seq ( ) const

inlineoverridevirtualnoexcept

Monotonic change counter (each successful Publish adds 2).

Implements hf::SnapshotReader< T >.

SignalChange_()

template<typename T >

void hf::SeqlockSnapshot< T >::SignalChange_ ( )

inlineprivatenoexcept

WaitForChange()

template<typename T >

bool hf::SeqlockSnapshot< T >::WaitForChange ( uint32_t  timeout_ms )

inlineoverridevirtualnoexcept

Block up to timeout_ms waiting for any change since the last call to WaitForChange / ClearWaitEvent.

Implements hf::SnapshotReader< T >.

Member Data Documentation

event_group_

template<typename T >

OS_EventGroup hf::SeqlockSnapshot< T >::event_group_ {}

private

event_group_created_

template<typename T >

bool hf::SeqlockSnapshot< T >::event_group_created_ {false}

private

kEventBit_

template<typename T >

constexpr OS_Ulong hf::SeqlockSnapshot< T >::kEventBit_ = 0x1U

staticconstexprprivate

payload_

template<typename T >

T hf::SeqlockSnapshot< T >::payload_ {}

private

seq_

template<typename T >

std::atomic<uint32_t> hf::SeqlockSnapshot< T >::seq_ {0}

mutableprivate

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The documentation for this class was generated from the following file:

• SeqlockSnapshot.h