xentara::memory::WriteSentinel< Object< Type > > Class Template Reference

A sentinel that protects write access to memory containing a single C++ object. More...

#include <xentara/memory/WriteSentinel_Object.hpp>

Inheritance diagram for xentara::memory::WriteSentinel< Object< Type > >:

Public Types
using	TargetObject = memory::Object< Type >
	The object type describing the structure.
using	Element = typename TargetObject::Element
	The C++ object type.

Public Member Functions
	WriteSentinel (const ObjectBlock< Type > &block)
	Constructor.
	WriteSentinel (const ObjectBlock< Type > &block, CopyOldValuesTag tag)
	Constructor that copies the old values, if necessary.
	~WriteSentinel ()=default
	Destructor.
internal auto	get () const noexcept -> Element &
	Gets the object.
auto	operator* () const noexcept -> Element &
	Gets the object.
auto	operator-> () const noexcept -> Element *
	Member access operator.
auto	commit (std::chrono::system_clock::time_point timeStamp) -> void
	Commits the changes.
template<std::same_as< process::Event >... AdditionalEvents> requires (sizeof...(AdditionalEvents) > 0)
auto	commit (std::chrono::system_clock::time_point timeStamp, const AdditionalEvents &...additionalEvents) -> void
	Commits the changes, raising additional events.
auto	commit (std::chrono::system_clock::time_point timeStamp, std::span< std::reference_wrapper< const process::Event > > additionalEvents) -> void
	Commits the changes, raising a list of additional events.
auto	commit () -> void
	deprecated Deprecated overload of commit() that uses the current time as time stamp.
auto	discard () -> void
	Discards any uncommitted changes.
auto	oldValue () const -> const Element &
	Returns the old value of the block.

Detailed Description

template<typename Type>
class xentara::memory::WriteSentinel< Object< Type > >

A sentinel that protects write access to memory containing a single C++ object.

Note

Objects of this class can be moved, but not copied.

Member Typedef Documentation

Element

template<typename Type >

using xentara::memory::WriteSentinel< Object< Type > >::Element = typename TargetObject::Element

The C++ object type.

TargetObject

template<typename Type >

using xentara::memory::WriteSentinel< Object< Type > >::TargetObject = memory::Object<Type>

The object type describing the structure.

Constructor & Destructor Documentation

WriteSentinel() [1/2]

template<typename Type >

xentara::memory::WriteSentinel< Object< Type > >::WriteSentinel

(

const ObjectBlock< Type > &

block

)

Constructor.

Attention

The new values will be default constructed. To initialize the new values with the old values, use the other constructor.

Parameters

block

The memory block you wish to write to

WriteSentinel() [2/2]

template<typename Type >

xentara::memory::WriteSentinel< Object< Type > >::WriteSentinel	(	const ObjectBlock< Type > &	block,
		CopyOldValuesTag	tag
	)

Constructor that copies the old values, if necessary.

This constructor will initialize the new values with copies of the old values.

Parameters

block	The memory block you wish to write to
tag	Always pass kCopyOldValues as this parameter

~WriteSentinel()

template<typename Type >

xentara::memory::WriteSentinel< Object< Type > >::~WriteSentinel ( )

default

Destructor.

Discards any uncommitted changes.

Member Function Documentation

commit() [1/4]

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::commit

(

)

-> void

deprecated Deprecated overload of commit() that uses the current time as time stamp.

Deprecated:

Replaced by commit(std::chrono::system_clock::time_point timeStamp)

commit() [2/4]

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::commit

(

std::chrono::system_clock::time_point

timeStamp

)

-> void

Commits the changes.

Warning

Do not access the data after you have called commit() or discard()!

Parameters

timeStamp

The time stamp to be used when raising change events.

commit() [3/4]

template<typename Type >

template<std::same_as< process::Event >... AdditionalEvents>
requires (sizeof...(AdditionalEvents) > 0)

auto xentara::memory::WriteSentinel< Object< Type > >::commit	(	std::chrono::system_clock::time_point	timeStamp,
		const AdditionalEvents &...	additionalEvents
	)		-> void

Commits the changes, raising additional events.

This overload allows you to specify one or more additional events to raise together with any change events resulting from the commit. The change events and additional events will be raised atomically as a block, as described in process::Event::raise().

Warning

Do not access the data after you have called commit() or discard()!

Parameters

timeStamp	The time stamp to be used when raising events.
additionalEvents	Additional events to raise together with the change events.

commit() [4/4]

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::commit	(	std::chrono::system_clock::time_point	timeStamp,
		std::span< std::reference_wrapper< const process::Event > >	additionalEvents
	)		-> void

Commits the changes, raising a list of additional events.

This overload allows you to specify a list of additional events to raise together with any change events resulting from the commit. The change events and additional events will be raised atomically as a block, as described in process::Event::raise().

Warning

Do not access the data after you have called commit() or discard()!

Parameters

timeStamp	The time stamp to be used when raising events.
additionalEvents	Additional events to raise together with the change events.

See also

process::EventList

process::FixedEventList

process::StaticEventList

discard()

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::discard

(

)

-> void

Discards any uncommitted changes.

Warning

Do not access the data after you have called commit() or discard()!

get()

template<typename Type >

internal auto xentara::memory::WriteSentinel< Object< Type > >::get ( ) const -> Element &

noexcept

Gets the object.

Returns

The object

oldValue()

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::oldValue

(

)

const -> const Element &

Returns the old value of the block.

This function can be used to access the old value of the block for memory resources that write by allocating a new block and swapping it in for the old one on commit. For memory resources that write data in place, the returned object provides access to the same memory as the writer itself.

Returns

A reference to the old (current) value of the block.

Warning

Do not access the data after you have called commit() or discard()!

operator*()

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::operator* ( ) const -> Element &

noexcept

Gets the object.

Returns

The object

operator->()

template<typename Type >

auto xentara::memory::WriteSentinel< Object< Type > >::operator-> ( ) const -> Element *

noexcept

Member access operator.

Returns

A pointer to the object